JP2001179420A - Die cast die, and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a die cast die which is sufficient in corrosion resistance against the molten or partially solidified metal, excellent in releasability and capable of increasing the service life, and its manufacturing method. SOLUTION: In the die cast die to cast the molten or partially solidified metal, a part of or an entire part of a surface in contact with at least the molten or partially solidified metal is modified into the surface of a compound or a mixture of a die base metal element modified by the ion implantation and an implanted element.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die casting die for molding a metal in a molten or semi-molten state, such as an aluminum alloy, a magnesium alloy, a zinc alloy, and the like, and a method for producing the same.

[0002]

2. Description of the Related Art In a die for a die-casting, it has been widely practiced to coat a surface in contact with a molten metal as a molding material. Most of them use a physical vapor deposition method such as PVD method or a chemical vapor deposition method such as CVD method, and apply titanium carbide (TiC), titanium nitride (T
iN), a film of titanium carbonitride (TiCN) or the like with a thickness of several μm.

[0003] These coatings are high in hardness and excellent in abrasion resistance. In terms of corrosion resistance to the molten metal to be cast, these coatings are different from those of steel, nickel alloy, cobalt alloy, tungsten base alloy and the like of a mold base material. Although it has the advantage of being excellent, it is not sufficient in terms of heat resistance to extend the life of the mold.

To solve this problem, Japanese Patent Laid-Open No.
No. 12266 describes that a base material of a mold is coated with a ceramic film made of TiAlN (titanium aluminum nitride) having better heat resistance than these films.

According to this TiAlN film, T
Although the durability of the mold can be improved to some extent as compared with a film such as iN, film defects and the like, which are problems of the film forming method itself such as the PVD method and the CVD method, occur, and the mold has a long service life. It was still not enough to make the transition.

This is because the molten metal penetrates into the base material from a defective portion such as a pinhole of the coating and the base material is eroded. Even if the coating itself is not eroded, the function of the coating is impaired.

[0007] This is described in the publication "Mold Technology, Vol. 5, No. 10 (1990), page 31". In practice, however, titanium carbide (PVD or CVD) is used. T
iC), titanium nitride (TiN), titanium carbonitride (TiC)
It is widely known to those skilled in the art that coatings such as N) and titanium aluminum nitride (TiAlN) have defects such as pinholes, which adversely affect the corrosion resistance of the mold against molten metal. Therefore, in the above publication, PVD method and CVD
Because the film formed by the method does not have sufficient corrosion resistance due to local erosion phenomenon due to its surface defects, a multilayer coating is provided as a countermeasure or a chrome plating film is provided as an undercoat It is suggested to improve the corrosion resistance.

[0008]

However, the method of providing a chromium plating film, when applied to a die for aluminum die casting, causes chromium in the plating film to react with aluminum as molten metal to form an alloy. Substantial improvement in corrosion resistance was difficult. In addition, the use of a multilayer film increases the cost, makes it difficult to design the film such as setting the film thickness, and increases the film stress.

Further, even if a film having a bond containing a metal such as titanium (Ti) or chromium (Cr) is formed by the PVD method, the CVD method, or the like, the film becomes a complete ceramic film. And some metal components such as titanium and chromium remain. The metal component is oxidized by the heat of the molten metal to be cast to accelerate the deterioration of the mold, or reacts with the molten metal to cause seizure or melting.

That is, the metal component remaining in the coating and the molten metal to be cast form an intermetallic compound at a high temperature, and this intermetallic compound adheres to the die surface (seizure), or the molten metal, that is, the die-cast product side. In this case, the mold is damaged (melted).

This is a phenomenon peculiar to die casting in which a molten metal is cast using a metal base metal mold, and is also a problem.

[0012] In particular, in die casting, in which a molten metal is cast at a high speed, there is a problem that peeling is likely to occur from an interface between a mold and a coating. This is because, due to the large frictional resistance between the molten metal flowing on the surface and the coating film, the coating film is peeled off from the mold when the molten metal flows on the mold surface.

Therefore, there is no film defect such as pinholes or residual metals, the adhesion between the film and the mold is high, and reducing the frictional resistance of the surface is the biggest problem of the die casting mold.

The present invention has been made in view of the above-mentioned problems of the prior art, and has sufficient corrosion resistance to a metal in a molten or semi-molten state, has good mold release properties, and has a long life. An object of the present invention is to provide a die casting mold capable of extending the life and a method of manufacturing the same.

[0015]

According to a first aspect of the present invention, there is provided a die casting mold for casting a metal in a molten or semi-molten state. A part or all of a surface in contact with a metal in a semi-molten state is a compound surface or a mixture surface of a base material element modified by ion implantation and an implanted element.

According to a second aspect of the present invention, there is provided a die casting mold,
In a die casting mold for casting a metal in a molten or semi-molten state, at least a part or all of a surface in contact with the metal in the molten or semi-molten state is coated with a ceramic film modified by ion implantation. It is characterized by the following.

According to the third aspect of the present invention, there is provided a die casting mold,
In a die casting mold for casting a metal in a molten or semi-molten state, at least a part or all of the surface in contact with the metal in the molten or semi-molten state, nitride-based ceramic, oxide-based ceramic, carbide-based ceramic, A ceramic film containing at least one selected from boride-based ceramics is formed, and ions containing at least one of nitrogen ions, oxygen ions, carbon ions, boron ions, and an inert gas are implanted into the ceramic film. It is characterized by having been done.

According to a fourth aspect of the present invention, there is provided a die casting mold,
In a die casting mold for casting a metal in a molten or semi-molten state, at least a part or all of the surface in contact with the metal in the molten or semi-molten state, nitride-based ceramic, oxide-based ceramic, carbide-based ceramic, A ceramic film containing at least one selected from boride-based ceramics is formed, and the ceramic film is subjected to at least one treatment selected from a nitriding treatment, an oxidation treatment, a carbonization treatment, and a boride treatment. It is characterized by the following.

According to a fifth aspect of the present invention, there is provided a method of manufacturing a die casting die for casting a metal in a molten or semi-molten state, wherein the method is in contact with at least the metal in the molten or semi-molten state. The method is characterized by including a step of implanting ions into part or all of the surface.

According to a sixth aspect of the present invention, there is provided a method of manufacturing a die casting mold for casting a metal in a molten or semi-molten state, wherein the method is in contact with at least the metal in the molten or semi-molten state. The method includes a step of forming a ceramic film on part or all of the surface, and a step of implanting ions into the surface of the ceramic film.

According to a seventh aspect of the present invention, there is provided a method of manufacturing a die casting die, wherein the ceramic film is made of a nitride ceramic, an oxide ceramic, A ceramic film containing at least one selected from carbide-based ceramics and boride-based ceramics, wherein the ions are ions containing at least one of nitrogen ions, oxygen ions, carbon ions, boron ions, and an inert gas. It is characterized by the following.

According to a eighth aspect of the present invention, there is provided a method for manufacturing a die casting mold for casting a metal in a molten or semi-molten state, wherein the method is in contact with at least the metal in the molten or semi-molten state. Forming a ceramic film containing at least one selected from a nitride ceramic, an oxide ceramic, a carbide ceramic, and a boride ceramic on part or all of the surface; Performing at least one treatment selected from a treatment, an oxidation treatment, a carbonization treatment, and a boride treatment.

According to the first and fifth aspects of the present invention, the ion implantation is a technique for accelerating ions to forcibly add an element to the surface of a mold. That is, by injecting ions into at least a part or all of the surface of the die casting die that is in contact with the metal in the molten or semi-molten state, collision between the elements to be injected of the die base material and the ions to be injected, The recoil excites the elements on the surface to be implanted, so that the elements on the surface to be implanted and the elements to be implanted are synthesized, and a compound surface or a mixture surface thereof is obtained.

On the surface into which the ions are implanted, the crystals are small, dense and uniform, and crystal growth due to heat can be suppressed. Further, the hardness of the ion-implanted base material surface is improved, the coefficient of friction is reduced, and the wear resistance is improved.

Further, the desired base material surface can be produced by appropriately changing the elements to be implanted and the ions to be implanted. Further, by changing the ion implantation conditions, it is possible to form a surface in which the ion amount and the ion implantation depth of the base material surface are changed.

According to the second and sixth aspects of the present invention, in order to form a ceramic film on at least a part or all of a surface of a die for die casting that comes into contact with a metal in a molten or semi-molten state, it is necessary to use a physical method. A PVD method as a vapor deposition method, a CVD method as a chemical vapor deposition method, or the like is used.

As described above, defects such as pinholes and residual metals exist on the surface of the ceramic film formed by such a film forming method, but the pinholes disappear by ion implantation into the surface of the ceramic film. Alternatively, the metal is completely removed from the surface of the ceramic film by being diffused, and the residual metal is also combined with the implanted ions to form a complete ceramic film.

The surface of the ceramic film completely blocks the contact between the metal in the molten or semi-molten state and the mold base material,
The metal can be prevented from penetrating into the mold base material.

The surface of the ceramic film into which the ions are implanted has small, dense and uniform crystals, and can suppress crystal growth due to heat. Further, the hardness of the base material surface is improved, the friction coefficient is reduced, and the wear resistance is improved.

According to the third and seventh aspects of the present invention, at least one of a nitride ceramic, an oxide ceramic, a carbide ceramic, and a boride ceramic formed by a PVD method, a CVD method, or the like. By implanting ions containing at least one of nitrogen ions, oxygen ions, carbon ions, boron ions, and an inert gas into the ceramic film containing the film, collisions and recoils with ions implanted with the metal present on the surface of the ceramic film are performed. As a result, the surface of the ceramic film is excited and reacted, the surface of the ceramic film is reformed into a complete ceramic surface containing no metal, and a surface having excellent heat resistance and oxidation resistance can be obtained.

When an inert gas (argon, neon, or the like) is injected, a compound with a metal is not formed as in the case of ion injection, but by forming a mixture surface with a simple metal, The same operation and effect as those of the ion-implanted surface are exhibited.

Further, by injecting ions containing at least one of nitrogen ions, oxygen ions, carbon ions, boron ions and an inert gas into the ceramic film, the pinholes are eliminated or diffused, so that the pinholes are removed from the surface of the ceramic film. Is completely removed. Such a ceramic film surface can completely block the contact between the molten or semi-molten metal and the mold base material, and can prevent the metal from penetrating into the mold base material.

As described above, by removing film defects such as residual metal and pinholes, excellent heat resistance and oxidation resistance can be obtained.
The inherent properties of ceramics, such as high hardness, excellent abrasion resistance, and excellent corrosion resistance to a cast molten or semi-molten metal, can be maximized.

According to the fourth and eighth aspects of the present invention, the ceramic film formed by the PVD method, the CVD method or the like is subjected to at least one treatment selected from a nitriding treatment, an oxidation treatment, a carbonization treatment and a boride treatment. By performing the above, the surface of the ceramic film on which the residual metal is present is modified into a complete ceramic surface containing no metal, and a surface having excellent heat resistance and oxidation resistance can be obtained.

The die casting mold thus obtained is excellent in heat resistance and oxidation resistance, high in hardness and excellent in abrasion resistance, and is suitable for casting a molten or semi-molten metal. The original characteristics of ceramics, such as excellent corrosion resistance, can be maximized.

In the first to eighth aspects of the present invention, the term “die casting” refers to “a molten or semi-molten metal is press-fitted or poured into a precision mold, and a highly accurate casting with excellent precision is obtained. Casting method for mass production in a short time. "

[0037]

(Embodiment 1) Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 1 is a sectional view showing an ion implantation apparatus used in the method for manufacturing a die casting mold according to the present embodiment, and FIG. 2 is a perspective view showing the die casting mold according to the present embodiment.

As shown in FIG. 2, the die casting die 50 of the present embodiment has a cavity 5 for casting a molten metal.
1 are provided on a pair of mold bodies 52, 53 having contact surfaces 52a, 53a facing each other, and a slide pin mold 1 sandwiched between the mold bodies 52, 53.

The mold bodies 52, 53 are provided with contact surfaces 52a, 5
3a can be brought into close contact with each other and separated from each other.
An injection port 54 (hereinafter, referred to as an injection port 54) for forming an injection port for molten metal into a cavity (hereinafter, referred to as a cavity 51) formed by the cavity section 51 at the time of close contact is divided into two parts. In this state, it is formed so as to communicate with each cavity portion 51. The facing contact surfaces 52a, 53a of the mold bodies 52, 53 are brought into close contact with each other. In this state of contact, molten metal is injected into the cavity 51 from the injection port 54 to cast a casting. In FIG. 2, for simplicity of illustration, means for positioning the mold bodies 52 and 53 relative to each other and means for taking out a casting are omitted.

The slide pin type 1 has a cylindrical large-diameter shaft portion 1.
a and a cylindrical small-diameter shaft portion 1b are stepped pins connected in the axial direction, and the mold body 52 is adapted to correspond to the outer diameter of the large-diameter shaft portion 1a and the small-diameter shaft portion 1b. , 53 are disposed in semicircular recesses respectively formed on the contact surfaces 52a, 53a, and when the mold bodies 52, 53 are in close contact with each other, the large-diameter shaft portion 1a
Is fixed to the mold bodies 52 and 53 by being sandwiched between the mold bodies 52 and 53. In this fixing, the small-diameter shaft 1
b penetrates through the center of the cavity 51. Therefore, the slide pin mold 1 functions as a mold for forming a through hole at the center of the casting, and is taken out of the mold bodies 52 and 53 in the axial direction when the casting is taken out.

In the present embodiment, the reforming process is performed by ion implantation such that the outer peripheral surface of the small diameter shaft portion 1b of the slide pin mold 1 held by the mold main bodies 52, 53 is brought into contact with the molten metal. As such a slide pin type 1, S
KD61 (HRC52) is used as a base material. In addition, since the slide pin mold 1 is pulled out from a solidified metal (cast product) after casting, in addition to the erosion resistance, oxidation resistance, and heat resistance required for a normal die casting mold, wear resistance and high hardness are required. And other characteristics are required. In this embodiment, the diameter of the small-diameter shaft portion 1b is 8 mm and the length is 110 mm.
mm, the diameter of the large-diameter shaft portion 1a is 18 mm, and the length is 80 m.
m.

The ion implanter 30 for performing the above-mentioned reforming process
Has a vacuum vessel 7 and a holder 2 provided in the vacuum vessel 7 as shown in FIG.

The holder 2 holds the large-diameter shaft portion 1a in a state where the slide pin mold 1 is set up, so that the large-diameter shaft portion 1a on the small-diameter shaft portion 1b side is partially held in the vacuum vessel 7 by the holder 2.
And the entire small-diameter shaft portion 1b is projected above the holder 2, so that the protruding portion can be subjected to a reforming process by ion implantation.
The holder 2 is fixed to a cooling plate 2a connected to a cooling water supply device (not shown), and is cooled by the cooling plate 2a.

On the upper part of the vacuum vessel 7, a slide pin type 1
An ion source 3 for supplying ions 8 to be injected into the large-diameter shaft portion 1a and the small-diameter shaft portion 1b into the vacuum vessel 7 is provided. The ions 8 from the ion source 3 are projected above the holder 2 and The outer peripheral surfaces of the small-diameter shaft portion 1b and the large-diameter shaft portion 1a of the slide pin mold 1 are irradiated. An introduction port 4 for introducing an ionized gas communicates with the ion source 3.

Further, an ion flow measuring device 5 for measuring the number of ions applied to the slide pin mold 1 is arranged in the vacuum vessel 7. A vacuum pump 6 is connected to the vacuum container 7.
Thus, the pressure is reduced to a predetermined pressure.

Next, a step of implanting ions into the surface of the slide pin mold 1 of the die casting mold 50 by the ion implantation apparatus 30 having the above configuration will be described.

In this ion implantation apparatus 30, the vacuum pin 6 is evacuated by the vacuum pump 6 while the slide pin mold 1 is held upright on the holder 2, and 6 × 10 ⁻⁴ Pa
The following high vacuum is used. Then, the ions 8 are irradiated from the ion source 3 onto the outer peripheral surfaces of the small diameter shaft portion 1b and the large diameter shaft portion 1a of the slide pin mold 1 protruding from the holder 2.

In the present embodiment, nitrogen gas is ionized by introducing 1 to 5 SCCM of nitrogen gas into an ionizer (not shown) and generating plasma. This ionized N
⁺ Ions and N ₂ ⁺ ions are mass-separated, and only desired nitrogen ions are introduced into the ion source 3 through the ion inlet 4.

In this case, the accelerated energy of the irradiated nitrogen ions
Energy of 45 keV and beam current density of 40 μA / cm
²And The ion irradiation dose is 1.5 × 10¹⁸ions /
cm ²And The method of the ion source 3 is
It is not limited to the method used for the form,
A man type, a bucket type, or the like may be employed.

The surface 1c of the slide pin mold 1 (base material 9) formed by the above method is, as shown in FIG.
At a depth of 1500 ° from the surface 1c, the injected nitrogen-containing FeN layer 10 exists as a compound surface. The FeN layer 10 is composed of FeN synthesized by exciting the Fe element by collision and recoil between the metal Fe on the surface 1 c of the slide pin type 1 and the implanted nitrogen ions.
Layer.

At this time, nitrogen ions are implanted so as to be in a supersaturated state.
At a depth of 500 °, complete F without metal Fe
It is modified into a compound layer of eN or a mixture layer of FeN compound and nitrogen, from which the amount of nitrogen decreases gradually toward the base material 9.

As described above, the nitrogen ions are supplied to the slide pin type 1
When supersaturated implantation is performed on the surface 1c, the acceleration energy of the irradiated ions is desirably 5 keV or more. If the acceleration energy is less than 5 keV, the processing surface of the surface 1c is excessively damaged by the etching effect, which is not preferable. On the other hand, if the acceleration energy is 200 keV or more, the treated surface is heated, which adversely affects the base material 9, which is not preferable. Beam current density 200μA / cm
^In the case of ^two or more, the treated surface becomes rough, which is not preferable for forming a precise functional surface of the mold. It should be noted that the beam current density can be implemented even at 5 μA / cm ² .

In this embodiment, N ₂ ⁺ ions are implanted, but N ⁺ ions may be implanted, or both N ₂ ⁺ ions and N ⁺ ions may be implanted.

Using such a slide pin mold 1, a magnesium alloy (AZ91D) was actually cast by combining a pair of mold bodies 52 and 53 as shown in FIG.
The mold bodies 52 and 53 have not been processed.

As a result, in the case of a slide pin type subjected to a gas nitrocarburizing treatment, which is one of the conventional treatment methods, 30
At the 00 shot, the fusion of magnesium to the mold surface was severe, the slide pin mold could not be removed from the cast product, and the surface was severely deteriorated by abrasion, making casting difficult.

On the other hand, as in the present embodiment, the slide pin type 1 in which nitrogen ions are implanted into the surface 1c of the base material 9 is used.
When was used, casting that satisfied the product standard was possible even with 8000 shots.

Further, when the magnesium fused to the slide pin mold 1 was removed with a remover and the surface thereof was observed, in the case of the conventional gas nitrocarburized slide pin mold, the scratches at the time of removal were easily confirmed. And erosion considerably progressed. On the other hand, in the slide pin mold 1 of the present embodiment, scratches and erosion were only slightly recognized.

Further, the casting of the product and the removal of the magnesium fused to the slide pin mold 1 were repeated to confirm the final life until the slide pin mold became completely unusable. In the case of the slide pin type, the damage is noticeable at 15,000 shots, and erosion occurs over the entire outer peripheral surface, and the fusion of magnesium is intense. This caused the slide pin type to slide and could not be removed, making it unusable.

On the other hand, with the slide pin mold 1 of the present embodiment, a product satisfying the product standard could be cast even after 25,000 shot casting.

According to the present embodiment, the surface 1c of the slide pin die 1, which is a die-casting die, is modified into a complete FeN layer free of metallic Fe by supersaturated nitrogen ion implantation. Crystals can be refined and densely uniform. Thereby, crystal growth due to heat during use at a high temperature can be suppressed. Also, FeN
On the surface of the layer, the coefficient of friction is reduced, the wear resistance is improved, and the hardness is also improved because crystal distortion and compressive stress remain due to ion implantation. Further, in the slide pin mold 1, the progress of deterioration of the mold surface is slowed down,
Good mold releasability can be maintained, and it is difficult for the cast product to be damaged and the mold life is prolonged.

In this embodiment, the same effect can be obtained by performing the processing performed on the slide pin mold 1 on the surfaces of the mold bodies 52 and 53 where the cavities 51 are formed. .

(Embodiment 2) Embodiment 2 of the present invention will be described. The die casting die according to the present embodiment has the same configuration as that of the first embodiment, and FIGS. 1 and 2 will be used in the following description.

In the present embodiment, as the base material 9 of the slide pin mold 1 of the first embodiment, an unheated MA
S1 is used. In the present embodiment, the small-diameter shaft portion 1b of the slide pin mold 1 has a diameter of 15 mm and a length of 120 m.
m, and the large-diameter shaft portion 1a has a diameter of 20 mm and a length of 80 mm
The slide pin mold 1 is processed so that the outer peripheral surface of the small-diameter shaft portion 1b has a cavity 51.
In contact with the molten metal.

The outer peripheral surfaces of the small-diameter shaft portion 1b and the large-diameter shaft portion 1a of the slide pin mold 1 are coated with a TiN film to a thickness of 3 μm by using a film forming apparatus of a plasma CVD method.
A TiAlN film as a ceramic film is 3 μm on the N film.
It was coated to form a two-layer structure. In order to improve the adhesion between the slide pin mold 1 and the base material, a TiN film as an intermediate layer was coated on the base material, and a TiAlN film having excellent heat resistance was coated as a mold surface. Things.

Next, the ion implantation apparatus 30 shown in FIG.
The step of implanting ions into the surface of the slide pin mold 1 having the two-layer structure will be described.

While the slide pin mold 1 is held in the holder 2 of FIG. 1, the inside of the vacuum vessel 7 is evacuated by the vacuum pump 6 to a high vacuum of 6 × 10 ⁻⁴ Pa or less. Then, ions 8 are irradiated from the ion source 3 to the surface of the two-layered TiAlN film of the slide pin type 1.

In the present embodiment, nitrogen gas is ionized by introducing 1 to 5 SCCM of nitrogen gas into an ionizer (not shown) and generating plasma. The ionized N ⁺ and N ₂ ⁺ ions are separated by mass to obtain a desired ion ratio (for example, 1: 2), and the ion inlet 4
From the ion source 3. The acceleration energy of the irradiated nitrogen ions is 45 keV and the beam current density is 40 μA /
cm ² . The amount of ion irradiation is 1.5 × 10 ¹⁸ ions
s / cm ² .

The surface of the slide pin mold 1 formed by the above method is, as schematically shown in FIG.
The TiN film 12 formed by the above-mentioned plasma CVD method exists on the upper surface of the MAS 1 of the above, and the TiAlN film 13 by the above-mentioned plasma CDV method exists on the upper surface of the TiN film 12. At a depth of 1500 ° from the surface of the TiAlN film 13, there is a modified TiAlN layer 14 as a modified ceramic film containing ion-implanted nitrogen.

The modified TiAlN layer 14 is formed of the metal Ti existing in the TiAlN film 13 on the surface of the slide pin mold 1.
A modified TiAlN layer 14 containing TiAlN synthesized by exciting the Ti element or the Al element by collision or recoil between the Al and metal Al and the implanted nitrogen ions. At this time, by implanting nitrogen ions so as to be in a supersaturated state, a depth of 1500 ° at which the nitrogen ions penetrate is reformed into a complete TiAlN layer 14 in which no metal Ti or metal Al is present. Towards 11, the amount of nitrogen gradually decreases.

Further, the modified Ti implanted with nitrogen ions
The surface of the AlN layer 14 has small, uniform and dense crystals. In addition, T formed by plasma CVD
The iAlN film 13 has a hole-like defect called a pinhole, but by implanting nitrogen ions,
Since the components on the surface of the TiAlN film 13 are diffused by the implanted ions, the pinholes are also diffused at the same time and no longer exist on the surface. This can be confirmed, for example, by an etching test.

As described above, the nitrogen ions are transferred to the TiAlN film 13.
When supersaturated implantation is performed on the surface of the substrate, the acceleration energy of the irradiated ions is preferably 5 keV or more. If the acceleration energy is less than 5 keV, it is not preferable because damage to the treated surface becomes excessive due to the etching effect. On the other hand, if the acceleration energy is 200 keV or more, the treated surface is heated, which adversely affects the base material 11, which is not preferable. When the beam current density is 200 μA / cm ² or more, the treated surface is roughened, which is not preferable for forming a precise mold functional surface.

Using such a slide pin mold 1, aluminum (ADC 12) was actually cast by combining a pair of mold bodies 52 and 53 as shown in FIG. The mold bodies 52 and 53 have not been processed.

As a result, in the conventional case in which the base material 11 is merely a slide pin type made of MAS1 and is coated with a TiN film and a TiAlN film by the plasma CVD method, 1
At 3000 shots, the aluminum was strongly fused to the surface of the slide pin mold, and the slide pin mold had cavity 5
No. 1 (cast product) did not come off, and casting became difficult.

On the other hand, as in this embodiment, ions are implanted so that the surface of the TiAlN film 13 is
When the slide pin mold 1 having the AlN layer 14 was used, there was no problem in the operation of the slide pin mold 1 even with 55,000 shots, and casting satisfying the product standard was possible.

Further, in a conventional slide pin type in which only a TiN film and a TiAlN film were formed by the plasma CVD method, after removing the aluminum fused to the surface of the TiAlN film with a removing agent, the surface was observed. However, melting damage was confirmed in the TiAlN film, and peeling and flaws were also generated.

On the other hand, in the slide pin mold 1 of the present embodiment, after casting until the fusion of aluminum occurs on the surface of the modified TiAlN layer 14, the surface from which aluminum was removed was observed. No erosion, peeling or scratches were observed, and the initial state was maintained.

Further, the casting of the product and the removal of the aluminum fused to the slide pin mold 1 were repeated, and the final life until the slide pin mold could not be used completely was confirmed. In the conventional slide pin type described above, Ti
AlN film almost disappeared at 36000 shots, melting damage progressed, aluminum was severely fused, and even if the fused aluminum was removed, fusion immediately occurred, and the slide pin type could not slide and could not come off. , Became unusable.

On the other hand, with the slide pin mold 1 of the present embodiment, a product satisfying the product standard could be stably cast even with 175000 shot casting.

As described above, by using the slide pin mold 1 of the present embodiment, the progress of deterioration of the mold surface is slowed down, and good mold releasability is maintained. It can be performed.

Further, according to the present embodiment, the base material 11 of the slide pin die 1 of the die-casting die is applied to the TiN film 1.
2 and a TiAlN film 13 on the TiN film 12.
After covering the surface of the TiAlN film 13, nitrogen ions are supersaturated and implanted into the surface of the TiAlN film 13.
The metal components Ti and Al existing therein are nitrided, and the surface of the slide pin mold 1 can be made into a modified TiAlN layer 14 which is a complete ceramic, and the metal component on the surface reacts with the molten metal. Can be prevented.

Thus, the phenomenon that the molten metal is fused to the surface of the slide pin mold 1 can be eliminated.
The advantage of high hardness, which is a characteristic of the ceramic film, and excellent wear resistance and corrosion resistance to the molten metal to be cast can be maximized.

In addition, since pinholes on the surface of the TiAlN film 13 can be eliminated and molten metal can be prevented from penetrating from the pinholes into the base material 11 during casting, fusion and peeling caused by this can be prevented. Melting damage can be eliminated. Furthermore, Ti modified by supersaturated ion implantation
Since the crystal on the surface of the AlN layer (modified TiAlN layer 14) is refined and densely uniform, when used as a die-casting mold, the formation of oxides due to heat is suppressed, and wear is reduced. In addition, since crystal growth is also suppressed, progress of deterioration can be delayed.

In particular, in the slide pin type 1 which is pulled out in the axial direction as in the present embodiment, due to the high hardness of the ion-implanted surface and the reduction of the friction coefficient, scratches due to pulling out are particularly difficult to occur, and the durability is improved. There is also the effect of doing.

In the present embodiment, the TiN film 12 and the TiAlN film 13 are formed by the plasma CVD method. However, the same effect can be obtained by other methods such as CVD, PVD, and thermal spraying. Have

In the present embodiment, a TiAlN film 13 having excellent heat resistance is formed as a second layer on the TiN film 12 for improving the adhesion to the base material 11, and its T
Nitrogen ions were implanted into the surface of the iAlN film 13, but the ceramic film selected as the second layer was TiN, TiC
N, TiNO, TiAlCN, TiAlNO, TiCr
Other Ti-based ceramics such as N, CrN, CrNO, Cr
C such as CN, CrAlN, CrAlCN, CrAlNO
r-based ceramics, Al-based ceramics such as Al ₂ O ₃ , B
Similar effects can be obtained with a boride-based ceramic such as N, a nitride-based ceramic such as Si ₃ N _4, or a mixture thereof. In this case, the intermediate layer between the second film and the base material 11 can be appropriately changed from the TiN film 12.

Further, depending on the type of these films, the ions to be implanted can be appropriately selected from nitrogen, oxygen, carbon, boron, an inert gas or the like, and can be implanted. Depending on the combination of the film and the ions to be implanted, it is also possible to synthesize a compound other than the compound that constituted the film.
When oxygen ions are implanted into the 1N film 13, TiAl
Aluminum oxide and titanium oxide are generated on the surface of the N film 13. In this case, the same effect as in the present embodiment can be obtained. For these films and the ions to be implanted, it is desirable to select a material that is the most excellent in terms of material in terms of mold releasability, use temperature, hardness, reactivity, durability, cost, and the like.

In addition, according to ion implantation, since the implanted element can be supersaturated on the surface, a compound having various characteristics in which the metal element does not completely remain in the film, or a mixture of this compound and the implanted element A surface can be obtained.

It is possible to further heat-treat the slide pin type 1 in which nitrogen ions have been supersaturated into the TiAlN film 13. This heat treatment stabilizes the surface thermally and makes the surface harder. (For example, Hv
About 250).

(Embodiment 3) Embodiment 3 of the present invention will be described with reference to FIGS. FIG. 5 is a cross-sectional view showing an ion nitriding apparatus used in the method for manufacturing a die casting die of the present embodiment, and FIG. 6 is a perspective view showing the die casting die of the present embodiment. The die casting mold according to the present embodiment is used for casting a microscope frame.

As shown in FIG. 6, a die casting mold 60 of the present embodiment has a cavity 61 for casting a molten metal.
Are provided. An injection port 64 for injecting the molten metal into the cavity 61 is formed in one mold body 62. In FIG. 6,
In order to simplify the illustration, means for positioning the mold bodies 62 and 63 relative to each other and means for taking out a casting are omitted.

In the mold bodies 62 and 63, the cavity 61 is formed in a state where the opposed contact surfaces 62a and 63a are in close contact with each other. In this state of contact, molten metal is injected into the cavity 61 from the injection port 64. A casting is cast.
In the present embodiment, the inner surface of one mold body 63 forming the cavity 61 is processed.

As shown in FIG. 5, the ion nitriding device 31 for performing the inner surface treatment includes a vacuum furnace 16 provided with a vacuum pump 18 and a gas supply device 19.
The mold body 63 is set therein. The vacuum furnace 16 is cooled by cooling water (not shown). The inside of the vacuum furnace 16 is evacuated by a vacuum pump 18, and gas is supplied from a gas supply device 19 to the inside. The power supply unit 17 is connected to the mold body 63.

The die body 63 of the die casting die 60 is
The inner surface comes into contact with the molten metal. The mold body 63 is processed by a base material made of SKD61 (HRC50), and a microscope frame is cast from aluminum.

In the present embodiment, the inner surface of the mold body 63 (the inner surface of the cavity 61) and the surface thereof (the contact surface 63a around the cavity 61 that contacts the contact surface 62a of the other mold body 62) On the other hand, by using a high-frequency magnetron sputtering method, the Cr film is formed to at least 0.1 mm.
Then, the Cr film was coated with a Cr ₂ N film as a ceramic film at least 1.5 μm to form a two-layer structure as a whole. Since the inner surface of the mold body 63 is concave, the coating of each film was performed while adjusting the direction of the mold body 63. The two-layer structure is achieved by coating a Cr film as an intermediate layer in order to improve the adhesion to the mold base material, and coating a heat-resistant Cr ₂ N film as a ceramic film on the mold surface. It was done.

Next, a process of treating the surface of the mold body 63 by the ion nitriding apparatus 31 having the above-described configuration will be described. The mold body 63 is set in the ion nitriding apparatus 31, and the inside of the vacuum furnace 16 is evacuated by the vacuum pump 18 to 1.3 to 13P.
a, and then pure nitrogen gas is supplied to the gas supply device 1
9, and the pressure in the vacuum furnace 16 is controlled to 150 to 1500 Pa in accordance with the processing conditions. In the present embodiment, the pressure is controlled to 500 Pa.

In this state, a glow discharge is generated by applying a DC voltage of 250 V between the vacuum furnace 16 as an anode and the mold body 63 as a cathode and the power supply unit 17 therebetween. This ionizes pure nitrogen gas,
The ionized nitrogen is accelerated, and the nitrogen ions collide at high speed with the inner surface of the mold body 63 and the Cr ₂ N film on the peripheral surface.

At this time, the high kinetic energy of the nitrogen ions is converted into heat energy,
In addition to heating 3, some directly inject nitrogen ions and some cause cathode sputtering,
₂ pops out electrons and Cr atoms from the surface of the _N film, the Cr atoms form a CrN bonded to atomic nitrogen generated by electrons.

This CrN is deposited on the surface of the Cr ₂ N film, decomposed into the next lower nitride due to high temperature and collision with nitrogen ions, releases nitrogen, and partly returns to the plasma gas.
By repeating this phenomenon, the metal Cr is nitrided remaining in Cr 2 _N film formed using the RF magnetron sputtering method, it becomes a complete ceramic surface there is no residual metallic Cr, Cr ₂ The surface which was N changes to CrN, and is modified to a nitrogen-rich surface to become a mixture surface of ceramic and nitrogen.

The mold body 6 formed by the above method
7, a Cr film 21 is present on the upper surface of the base material 20 made of SKD 61, and a Cr ₂ N film 22 is present on the upper surface thereof, as schematically shown in FIG. Then, at a depth of 5000 ° from the surface that comes into contact with air (that is, comes into contact with the contact surface 62a of the other mold body 62), a layer (modified CrN layer) 23 that has been modified to CrN by ion nitriding is formed. The amount of nitrogen decreases from the modified CrN layer 23 toward the base material 20 in a graded manner. Therefore, at a depth of 5000 ° into which nitrogen ions are implanted, metal C
r has been modified to a completely ceramic CrN without the presence of r.

The Cr ₂ N film 22 formed by the high-frequency magnetron sputtering method has a hole-like defect called a pinhole. However, by ion-nitriding, surface components are diffused by ions. Therefore, the pinhole is also diffused at the same time and does not exist on the surface.

Using the mold body 63 as described above, FIG.
The casting is performed by assembling a die casting mold 60 shown in FIG.
The other mold body 62 has a contact surface 62
The same processing as described above is performed on the surface on the a side. Casting is performed by melting and supplying aluminum (ADC12).

As a result, in the case of a conventional die-casting die having a two-layer structure coated with a Cr film and a Cr ₂ N film formed by a high-frequency magnetron sputtering method,
At 8000 shots, erosion progressed from the pinholes on the film surface, the aluminum was severely fused, the mold could not be released, and casting became difficult.

On the other hand, when the die casting die 60 of the present embodiment was used, casting satisfying the product standard was possible even with 40000 shots. In this die casting mold 60, no erosion was confirmed even after 40000 shots, and the initial state was maintained.

[0104] Further, the final life until the die casting die could not be used completely was confirmed by repeating the casting of the product and the removal of the fused aluminum. As a result, the conventional die casting die was made of Cr ₂ N. Melting of the film progresses at 28,000 shots, severe fusion of aluminum occurs, and even if the fused aluminum is removed, fusion occurs immediately, making the film unusable. The inside dimensions were out of specification due to erosion. On the other hand, the die casting die 60 of the present embodiment was able to stably cast a product that satisfies the product standard even after the 110000 shot casting.

As described above, the mold body 62 according to the present embodiment,
By using the die-casting die 60 in combination with 63, the progress of the deterioration of the die surface is slowed down, and good releasability is maintained, so that the life can be extended until the die can no longer be used. it can.

Also, according to the present embodiment, the contact surfaces 62a, 63 of the die bodies 62, 63 of the die casting die 60.
a is coated with a Cr ₂ N film 22, and the surface thereof is subjected to ion nitriding, whereby the metal component Cr present in the Cr ₂ N film 22 is nitrided, and the surface is completely completed with the modified CrN layer 23. It is possible to make the CrN ceramic suitable for use and to prevent the metal component on the surface from reacting with the molten metal. Thereby, the heat resistance is higher than that of the Cr ₂ N film 22, the progress of oxidation is slowed, and the phenomenon that the molten metal is fused to the mold surface can be eliminated. In addition, it is possible to make the most of the advantages of having excellent wear resistance and corrosion resistance against the molten metal to be cast.

Further, pinholes on the surface of the Cr ₂ N film 22 can be eliminated, and the molten metal can be prevented from penetrating from the pinholes into the base material 20 during casting. Peeling, erosion, etc. can be eliminated. Furthermore, since the crystal on the surface of the CrN film (modified CrN layer 23) modified by the ion nitriding treatment is refined and densely uniform, when used as a die-casting mold, the oxide due to heat Is suppressed, wear is reduced, and crystal growth is also suppressed, so that the progress of deterioration can be delayed.

As described above, when ion nitriding is used, since the object to be processed is used directly as a cathode, the entire surface can be uniformly nitrided. As a result, even a die-casting die having a complicated shape can be uniformly processed with respect to the whole.

In the present embodiment, the Cr ₂ N ceramic film to be ion-nitrided is formed by the high-frequency magnetron sputtering method.
A film formed by a VD method, thermal spraying or the like has the same effect.

In this embodiment, a Cr ₂ N film 22 is formed as a second layer on the Cr film 21 for improving the adhesion to the base material 20, and the surface thereof is subjected to ion nitriding. However, the ceramic film selected as the second layer is made of Ti
N, TiCN, TiNO, TiAlN, TiAlCN,
Ti-based ceramics such as TiAlNO and TiCrN, Cr
N, CrO, CrNO, CrCN, CrAlN, CrA
Other Cr-based ceramics such as 1CN, CrAlNO, Al
Similar effects can be obtained with Al-based ceramics such as ₂ O ₃ , boride-based ceramics such as BN, nitride-based ceramics such as Si ₃ N ₄ , and mixtures thereof.

Further, in this embodiment, the ion nitriding method is used, but the gas nitriding method, the salt bath nitriding method, the gas soft nitriding method,
The same effect can be obtained by using a nitrosulphurizing method or a gas sulphurizing method, but from the viewpoint of removing pinholes present in the film,
Ion nitriding, which allows ions to strike the surface and diffuse pinholes, is desirable. In addition, a treatment selected from a nitriding treatment, an oxidation treatment, a carbonization treatment, and a boride treatment can be appropriately selected depending on the type of the above film. Depending on the combination of the film and the treatment, it is also possible to synthesize compounds other than the compounds that make up the film, and select the most excellent surface according to mold release, use temperature, hardness, reactivity, durability, cost, etc. It is desirable.

(Embodiment 4) Embodiment 4 of the present invention will be described with reference to FIG. FIG. 8 is a perspective view showing a die casting mold according to the present embodiment.

The die casting mold 70 is for casting a camera body, and has a pair of mold bodies 72 and 73 forming a cavity 71 for casting a molten metal. An injection port 74 for injecting the molten metal into the cavity 71 is formed in the mold body 72.

A core or insert is attached to a portion of each of the mold bodies 72 and 73 forming the cavity 71 so as to correspond to the shape of the casting. The mold bodies 72 and 73 are provided with the opposed contact surfaces 72a and 73.
A cavity 71 is formed in a state in which “a” is in close contact, and in this close contact state, molten metal is injected into the cavity 71 from an injection port 74 and casting is performed. In addition, in order to simplify illustration,
The means for positioning the mold bodies 72 and 73 relative to each other and the means for removing the cast product are omitted.

In this embodiment, the die casting mold 70 is used.
In the mold body 73 having a concave casting surface, processing is performed on the casting surface, and this processing is performed using the ion implantation apparatus 30 shown in FIG. Therefore, in the present embodiment, the slide pin mold 1 in FIG. SKD61 (HRC50) is used as a base material of the mold body 73.

The casting surface of the mold body 73 of the present embodiment is
It has a complicated shape with large and small irregularities, and the molten metal is easily fused to the innermost part (recess) of the complex shape. Therefore, it is required that the innermost portion be provided with erosion resistance, thermal oxidation resistance, and heat resistance. Therefore, the mold body 73
Low temperature thermal CVD on the entire surface of the mold base material in advance
Using a method, a TiN film as a ceramic film was formed to a thickness of 5 μm.

In this embodiment, in the ion implantation apparatus 30 shown in FIG.
3 is held by the holder 2. Further, a pulse power supply device (not shown) is connected between the holder 2 for holding the mold body 73 and the vacuum vessel 7, so that a negative voltage can be applied to the mold body 73. Other configurations in FIG. 1 of the present embodiment are the same as those of the first embodiment, and thus description thereof is omitted.

Next, the step of surface treatment of the mold body 73 will be described. First, with the mold body 73 placed on the holder 2 of the ion implantation apparatus 30, the inside of the vacuum vessel 7 is evacuated by the vacuum pump 6 to make a high vacuum of 8 × 10 ⁻⁴ Pa or less.

In the present embodiment, nitrogen gas is introduced into a non-illustrated ionizer at 1 to 5 SCCM to generate plasma and ionize the nitrogen gas. Next, the ionized N ⁺ ions and N ₂ ⁺ ions are mass-separated, and only desired N ₂ ⁺ ions are introduced into the ion source 3 from the ion inlet 4.

The ion source 3 irradiates the ions 8 toward the mold body 73. The acceleration energy at this time is, for example, a voltage of 80 V, and the N ₂ ⁺ ions are introduced so as to fill the inside of the vacuum vessel 7. . At this time, the ion introduction amount is such that the ion irradiation amount to the mold body 73 is 1.5 × 10 ¹⁸ i
ons / cm ² and the beam current density is 40 μA / cm
^{And 2} .

While introducing such N ₂ ⁺ ions into the vacuum vessel 7, the holder 2 was turned on by a pulse power supply (not shown).
A negative pulse voltage of 30 kV is applied to the mold main body 73 through. At this time, the pulse width of 2 μS is 5000
The pulse frequency was set to pps. Such a processing method
PSII (Plasma Immersion Ion Implantation) and a method called uneven portion of the casting surface of the mold body 73 by a negative pulse voltage, N ₂ against particular deepest portion (recess)
⁺ Ions can be implanted.

In this embodiment, the ion implantation apparatus 30 shown in FIG. 1 is used. However, the mold body 73 as an object to be processed is immersed in nitrogen plasma, and a negative pulse voltage is applied to the mold body 73. Another method such as a method of applying the voltage may be used.

The ionization by the above-mentioned PSII method
When injecting₂ ⁺Ions continuously in vacuum vessel 7
Instead of applying a negative pulse voltage while introducing
And N ₂ ⁺After introducing the ions into the vacuum vessel 7, once
N₂ ⁺Is stopped and the pulse voltage is applied to the mold body 73.
Apply and ion implant, then reintroduce ions
It is also possible to carry out by means.

The surface of the mold body 73 manufactured according to the present embodiment has a TiN film 25 as a ceramic film on the upper surface of the base material 24 as schematically shown in FIG.
At a depth of 1000 ° from the surface of the film 25, the modified Ti as a modified ceramic layer containing the implanted nitrogen is used.
An N layer 26 is present. This modified TiN layer 26 is made of T
This is a modified TiN layer containing TiN synthesized by exciting the Ti element by collision and recoil between the metal Ti existing in the iN film 25 and the implanted nitrogen ions.

In this case, T is set so as to be in a supersaturated state.
By implanting nitrogen ions into the iN film 25, at a depth of 1000 ° at which nitrogen ions penetrate, the TiN layer is reformed into a complete ceramic TiN layer in which metal Ti does not exist, and from the modified TiN layer 26 toward the base material 24. As a result, the amount of nitrogen gradually decreases. Complete ceramic modified TiN layer 26
In addition, the crystal is small, uniform and dense, and the pinholes existing in the TiN film 25 before the nitrogen ion implantation have disappeared.

Next, the die body 73 and the die body 72 were combined to form a die-casting die 70, and the camera body was actually cast with magnesium (AZ91D). T formed by the method
In the case of a die casting mold coated with an iN film, 230
In addition to the fusion of magnesium at the corners of the recesses of the casting surface in the 00 shot, fusion was also generated and accumulated near the gate portion for injecting the molten metal into the cavity.

On the other hand, when the die casting mold 70 of the present embodiment in which nitrogen ions are implanted into the surface thereof by the PSII method is used, the melting of magnesium on the casting surface of the mold and the vicinity of the gate portion can be performed even at 75,000 shots. There was no wear, and casting satisfying the product standards was possible.

When the surface of the TiN film was observed after removing the magnesium fused to the mold of the prior art with a removing agent, the TiN film was peeled or melted at the corner of the complicated shape or near the gate. Loss was confirmed, and scratches were also found. On the other hand, in the die casting mold 70 of the present embodiment, no peeling, erosion, scratches, etc. were confirmed, and the initial state was maintained.

Further, by repeating the casting of the product and the removal of the fused magnesium, and confirming the final life until the die casting die can no longer be completely used, the conventional die casting die was 86,000 shots. And T
The iN coating is almost completely lost and the erosion proceeds, and the fusion of magnesium is intense. Further, even if the fused magnesium is removed, the fusion occurs immediately and finally the molten metal is injected into the cavity. Due to severe abrasion in the vicinity, the dimensions were out of the standard and became unusable.

On the other hand, in the die casting mold 70 of the present embodiment, a camera body satisfying the product standard could be stably cast even after casting 450,000 shots.

According to this embodiment, the base material 24 of the die body 73 of the die casting die 70 is coated with the TiN film 25, and nitrogen ions are implanted into the surface thereof by the PSII method so as to be supersaturated. As a result, Ti, which is a metal component existing in the TiN film 25, is completely nitrided, and T
The surface of the iN film 25 is made of modified TiN which is a perfect ceramic.
The layer 26 can be used to prevent the metal component on the surface from reacting with the molten metal. Thereby, the phenomenon that the molten metal is fused to the surface of the mold can be avoided, and the advantages of high hardness, which is a characteristic of the TiN ceramic film, and excellent wear resistance and excellent corrosion resistance to the molten metal to be cast are obtained. be able to.

Further, by eliminating pinholes on the surface of the TiN film 25, it is possible to prevent molten metal from infiltrating from the pinholes into the mold base material 24 during casting. Peeling and melting of the film 25 can be eliminated. Further, the crystal on the surface of the TiN layer (modified TiN layer) 26 modified by ion implantation becomes finer,
And because it is densely uniform, when used as a die casting mold, the formation of oxides due to heat is suppressed,
Wear is reduced, and the progress of deterioration can be delayed.

In addition, the ion implantation surface has high hardness and a low friction coefficient, so that scratches and the like are not easily formed, and the durability is also improved. Further, by performing the ion implantation by the PSII method, it is possible to perform the ion implantation process on all surfaces even in a mold body for a camera body having a complicated shape.

In this embodiment, the low temperature thermal CVD method is used for forming the TiN ceramic film.
It goes without saying that the same effect can be obtained even if the film is formed by the D method, the PVD method, the thermal spraying or the like.

In the first to fourth embodiments, the so-called narrow-die casting, in which molten metal is press-fitted into precision die-casting dies 50, 60, and 70, is described. Due to its action, it can be universally applied to die casting in the broad sense defined above, including the technology described below.

For example, there is a technique called thixomolding (or thixocasting) in which a semi-molten metal is press-fitted into a mold and cast. Thixomolding is a technique used for precision casting of highly oxidizable metals such as magnesium.
It is to be injected and cast into a mold in a low-temperature, semi-molten state. Apart from this, there is a general casting technique in which molten metal is poured into a mold and then cast.

The present invention is intended to prevent the mold base material from being brought into contact with the metal to be cast, since the casting surface of the mold in contact with the metal to be cast has been modified into a perfect ceramic without defects. Therefore, the present invention can be applied to any casting method in which metal is cast using a metal mold, and produces an effect.

The technical idea having the following configuration is derived from the above-described specific embodiment. (Supplementary Note) (1) In a die casting mold for casting a molten or semi-molten metal, at least a part or all of a surface in contact with the molten or semi-molten metal is modified by ion implantation. A die casting die having a compound surface or a mixture surface in which a metal of a material element and an injection element does not exist.

(2) In a die casting mold for casting a metal in a molten or semi-molten state, at least a part or all of a surface in contact with the metal in the molten or semi-molten state is modified by ion implantation and at least the surface is modified. A die casting die, characterized by being coated with a ceramic film having no metal.

According to the die for die casting described in the appendix (1),
Even when the metal comes into contact with a molten or semi-molten metal, oxidation does not occur on the contact surface, and seizure and melting damage do not occur, so that the life of the mold can be extended.

According to the die-casting die described in (2),
By eliminating pinholes generated in the ceramic film, fusion with a molten metal, peeling and melting of the modified ceramic film can be prevented, and the life of the mold can be extended.

[0142]

According to the first and fifth aspects of the present invention, in a die casting mold for casting a metal in a molten or semi-molten state and a method of manufacturing the same, at least one surface in contact with the metal in the molten or semi-molten state. Ions are implanted in all or part of the surface, and the surface of the compound or mixture of the base material element and the implanted element is reformed, so that the modified surface is small, dense and uniform, and crystal growth by heat is prevented. Can be suppressed. In addition, the modified surface has an improved hardness, a reduced friction coefficient, and improved wear resistance.

As a result, the progress of deterioration of the mold surface is slowed down, good mold releasability can be maintained, and the life of the mold can be extended. Furthermore, since the occurrence of scratches and the like can be prevented by increasing the hardness of the surface and improving the wear resistance, scratches and the like hardly occur on the appearance of the cast product, the mold can be used for a long time, and the life of the mold can be extended.

According to the second and sixth aspects of the present invention, in a die casting mold for casting a metal in a molten or semi-molten state and a method of manufacturing the same, at least a part of a surface in contact with the metal in a molten or semi-molten state. A ceramic film is formed on the entire surface, and ions are implanted into the surface of the ceramic film to form a modified ceramic film. Therefore, the modified mold surface becomes a complete ceramic surface containing no metal component. For this reason, it is possible to prevent the metal component on the surface from reacting with the molten or semi-molten metal.

Thus, fusion of the molten or semi-molten metal to the mold surface can be prevented, the hardness is high, the abrasion resistance is excellent, and the molten or semi-molten metal to be cast can be prevented. The original characteristics of the ceramic film, such as excellent corrosion resistance, can be maximized. In addition, since the pinholes have disappeared in the modified ceramic film, it is possible to prevent the molten or semi-molten metal from penetrating from the pinholes into the base material during casting, improve corrosion resistance, and improve mold life. Life can be extended.

According to the third and seventh aspects of the present invention, in a die casting mold for casting a metal in a molten or semi-molten state and a method of manufacturing the same, at least a part of a surface in contact with the metal in the molten or semi-molten state. A ceramic film containing at least one selected from nitride-based ceramics, oxide-based ceramics, carbide-based ceramics, and boride-based ceramics is formed on all of them, and nitrogen ions, oxygen ions, carbon In order to modify the ceramic film by injecting ions containing at least one of ions, boron ions and inert gas, the material is the most important depending on the releasability, operating temperature, hardness, reactivity, durability, cost, etc. A good material can be selected to form the mold surface.

According to the fourth and eighth aspects of the present invention, in a die casting mold for casting a metal in a molten or semi-molten state and a method for producing the same, at least a part of a surface in contact with the metal in a molten or semi-molten state. A ceramic film containing at least one selected from nitride-based ceramics, oxide-based ceramics, carbide-based ceramics, and boride-based ceramics is formed on all of the surfaces, and the surface of the ceramic film is subjected to nitriding, oxidation, and carbonization. Treatment, the modification by at least one treatment selected from boration treatment, the metal component existing on the surface of the ceramic film can be completely ceramicized, and the crystal on the treated surface is refined,
Dense casting can be performed precisely and uniformly, and even a complicated shape die can be uniformly processed.

Further, the releasability, operating temperature, hardness, reactivity,
Depending on durability, cost, etc., the most suitable material and processing method can be selected to form the mold surface. Further, the progress of deterioration of the die surface of the die for die casting is slowed down, good releasability can be maintained, and the life of the die can be extended.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an ion implantation apparatus used for a method for manufacturing a die casting die according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view showing the die casting die according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating a layer configuration of a die casting mold according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view illustrating a layer configuration of a die casting mold according to a second embodiment of the present invention.

FIG. 5 is a sectional view showing an ion nitriding apparatus used in a method for manufacturing a die for die casting according to a third embodiment of the present invention.

FIG. 6 is an exploded perspective view showing a die casting mold according to a third embodiment of the present invention.

FIG. 7 is a sectional view showing a layer configuration of a die casting mold according to a third embodiment of the present invention.

FIG. 8 is an exploded perspective view showing a die casting die according to a fourth embodiment of the present invention.

FIG. 9 is a cross-sectional view showing a layer configuration of a die casting mold according to a fourth embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 1 slide pin type 9, 11, 20, 24 base material 10 FeN layer 12 TiN film 13 TiAlN film 14 modified TiAlN layer 21 Cr film 22 Cr ₂ N film 23 modified CrN layer 25 TiN film 26 modified TiN layer 50, 60, 70 Die casting mold 52, 53, 62, 63, 72, 73 Mold body

Claims (8)

[Claims] In a die casting mold for casting a metal in a molten or semi-molten state, at least a part or all of a surface in contact with the metal in the molten or semi-molten state is modified by ion implantation. A die-casting mold characterized by having a compound surface or a mixture surface of an element and an implanted element. 2. A die casting mold for casting a metal in a molten or semi-molten state, wherein at least a part or all of a surface in contact with the metal in the molten or semi-molten state is modified by ion implantation. A die casting die, characterized by being coated with: 3. A die casting mold for casting a metal in a molten or semi-molten state, wherein at least a part or all of a surface in contact with the metal in the molten or semi-molten state is a nitride ceramic or an oxide ceramic. , At least one selected from carbide-based ceramics and boride-based ceramics
And a ceramic film containing at least one of nitrogen ions, oxygen ions, carbon ions, boron ions, and an inert gas is implanted into the ceramic film. Mold. 4. In a die casting mold for casting a metal in a molten or semi-molten state, at least a part or all of a surface in contact with the metal in the molten or semi-molten state is made of a nitride ceramic or an oxide ceramic. , At least one selected from carbide-based ceramics and boride-based ceramics
A die for a die casting, wherein a ceramic film including at least one of the following is formed, and the ceramic film is subjected to at least one treatment selected from a nitriding treatment, an oxidation treatment, a carbonization treatment, and a boride treatment. 5. A method for manufacturing a die casting mold for casting a metal in a molten or semi-molten state, the method comprising the step of implanting ions into at least a part or all of a surface in contact with the metal in the molten or semi-molten state. A method for manufacturing a die for die casting, comprising: 6. A method for manufacturing a die casting mold for casting a metal in a molten or semi-molten state, wherein a ceramic film is formed on at least a part or all of a surface in contact with the metal in the molten or semi-molten state. A method for producing a die for a die casting, comprising: a step of implanting ions into the surface of the ceramic film. 7. The ceramic film according to claim 1, wherein the ceramic film includes at least one selected from a nitride ceramic, an oxide ceramic, a carbide ceramic, and a boride ceramic. 7. The method for producing a die casting die according to claim 6, wherein the ion is an ion containing at least one of an ion, a carbon ion, a boron ion, and an inert gas. 8. A method for manufacturing a die casting mold for casting a metal in a molten or semi-molten state, wherein at least a part or all of a surface in contact with the metal in the molten or semi-molten state is made of a nitride ceramic, an oxide, Forming a ceramic film containing at least one selected from ceramics, carbide ceramics, and boride ceramics; and nitriding, oxidizing, and carbonizing the ceramic film.
Performing at least one treatment selected from boring treatments.