JPS5933064A - Production of composite casting - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Kokuhaimei is a method for producing a coalesced product, specifically, it has a composite phase consisting of a mixture of metal and charcoal and compound particles such as tungsten carbide. This article relates to a method for manufacturing patrol forces by casting superior composite materials.

Conventionally, this type of composite material has been manufactured using a powder metallurgy method, for example, by combining tungsten carbide, powder, and Kobal 1 to
There is a method in which the powder is mixed with powder, molded, and then sintered, and the tljed sintered body is subjected to machining to produce the desired product. Only [7, its production jIl'E,"',i,'
□' □ is cumbersome, has low productivity, and is expensive to lose. Is there a limit to the shape and size of products that can be manufactured?9. I can't make something or something large (9,1).

It is our aim to provide an inexpensive and simple manufacturing method for the composite material F-1 having the shape and size of 51, which eliminates the disadvantages listed in 1. ].

Other objects of the present invention include excellent wear resistance, etc.
We provide a manufacturing method for composite materials suitable for molds, roll materials, etc. ``'T a desk.

The feature of the present invention is that when using molten metal such as iron or navel, and carbide powder with a larger specific gravity than that of a single molten metal (!: flj type, 17 type, 179, specific gravity i After that, by sedimenting the carbide particles, a composite phase in which molten metal and carbide particles are mixed is completely formed and solidified in a predetermined part of the mold. A composite casting is manufactured by cutting and removing a metal phase portion (consisting essentially only of metal) from a composite phase portion.

The following is a detailed explanation of Kihatsu. Figure 1 shows a concrete example of the manufacturing procedure for composite castings using wood starting methods. In the figure, (1) is the mold, (4) is the molten metal casting popper, (
6) is a ladle, and (7) is a carbide powder cast-5.

The cast chestnut (1) consists of an upper part (1 bow) and a lower part (1 and 2) (the part and the lower part may be integrally formed), and the molten metal part is the lower part (1 bow) as described below. 1.2) are satisfied,
The molten metal is cast as soon as it reaches the second part (1. 2) ζ:: Referred to as the "Product Department">.tJ-ron, the Product Department (1 and 2) is shaped into any shape and size depending on the purpose, base, and composite powder.Also, 1. For convenience of casting, the upper part (work 1) has a tapered shape that expands to "1" in the illustrated example, but it may have an appropriate shape "F" if it does not interfere with casting.

The mold (1) shown in the figure is a fired mold used for example in the lost wax precision casting method, and is installed in a case (3) in a furnace together with a pack sand mold (2). If heated, it can be used as a heat-insulating mold.

Carbide powder (P) is stored in the carbide powder input device (7), and is fed to the hopper (4) via the input amount adjusting pulp (8).
A predetermined amount of carbide powder is dispensed within '.

In the apparatus described in 1, □ molten metal is injected from the ladle (6) into the hopper (4), and carbide powder (P) is injected into the hopper (4).
) If injected into all hoppers, molten metal (V) and powder (P□
) is in a mixed state, and the three seams at the bottom of the hopper (
5) and is cast into the mold (1). At the beginning of casting, carbide particles (P)' are formed as shown in Fig. 2 (1).
The particles are almost uniformly dispersed over the entire area of the molten metal in the mold, but due to the difference in specific gravity of the molten metal, the heavier carbide particles settle downward, and as shown in the figure (ID), the product parts (1 and 2) ) accumulates in the molten metal (M)2 carbide particles (
A composite phase consisting of P') is formed.

Upper part (1 bow:) r, i result of gravity separation of carbide particles'
11, the result is essentially only molten metal. ′：：
: After solidifying the molten metal in this way, from the mold! Collect the cast body (C) in the shape shown in Figure 3, cut and remove the part (C.1) that is essentially made of metal along the a-a line, and The structure of the product part ('C) obtained as a composite casting is schematically shown in □. death,
When the metal (M) is used, the surface of the metal (M) is coated and the gaps between the particles are completely filled, and the carbide particles and metal form a strong knot. The ratio is '1:'1 to '3:l (volume ratio). □ ・″″-1-Note’ In IJF construction,
The molten metal was cast in many ways, exceeding 71 liters (4,000 liters) to form the product, but only one molten metal was cast, which corresponded to the riser required for the product part.
2 △ Toni J: The name of the composite casting is also strong in non-111 acid.

However, if the molten metal casting mechanism is restricted in this way, it becomes difficult to completely cover the surfaces of carbide particles and fill the gaps between the particles. Especially when throwing carbide powder! If the relative ratio of molten metal L to the amount of J is small, the temperature of the pig will decrease (・
(This is caused by the carbide powder taking away the heat from the molten metal) and the resulting viscosity rapidly approaches.
That's right, I'm currently #'>h. In order to avoid this problem, it is interesting to cast 14 times a day of molten metal, as described in +JFR, and let the carbide particles settle in the molten metal and coagulate from the particles to the product part. As Kl rises, carbide particles and gold are tightly bound together to form a dense outer composite structure. From this point of view, it is preferable that the ratio of the casting amount of the molten metal to the amount of the carbide powder is -1, for example: 1 part by weight of the carbide powder to 2 to 2 parts by weight of the molten metal. At the end of the day, if the product is sufficiently sedimented and aggregated by specific gravity separation, it can be administered! ? 1. Needless to say, the product should be long enough to form a complex phase of the product. □ In the casting of Mokuhaimei, it is necessary to mass-produce the mold and ensure that the carbide particles are sufficiently agglomerated in the product parts (1 and 2) before the drying process begins. For this purpose, it is preferable to begin dosing the carbide powder at the same time as the molten metal is cast, and to finish dosing the entire amount by the time about 415 of the total cast amount of the molten metal has been cast. However, due to the force of the cast molten metal, heat being taken away by the casting mold and the projected carbide particles, foaming may begin to solidify before the carbide particles have finished settling and agglomerating into the product. In order to delay the solidification, for example, the casting temperature of the molten metal is increased, the mold is preheated, or the carbide powder is preheated and administered. □It is also effective to implement a combination of 2 or more.・In addition to this temperature compensation method, it is also effective to select carbide powder that easily settles in the molten metal, ie, one with a large particle size, or one with a large difference in specific gravity from the molten metal. It is. −□
□ ・-□ The carbide powder used for the unexploded 1y'1 is a powder with a large specific gravity difference from the molten metal, as described above, in order to prevent rapid sedimentation in the molten metal and agglomeration in the product/product parts. □Strong bond with metal in composite phase: In order to obtain a bonded state, □Forged □Metal and metal joints are used. (1 for wetness)
One good one is preferred. Further, in order to improve the wear resistance of the cast material, it is desirable that the carbide particles themselves have high hardness. It is necessary to have a high melting point that does not melt or disappear easily.A preferable example of a silica that satisfies this requirement is tungsten carbide I.
) (Wc, W2c) i': □Raise vignetting□ru (specific gravity 15.7 (WC), 17."2"" (W 2C),
Melting point □2800°C). Curved tungsten carbide is also used for decapitation. However, since there are carbides with a specific gravity of about 4.9 to 17.2, in combination with the molten metal described below, the specific gravity is about 10.
It is desirable to choose the second option. These carbides can be used in a single or mixed bow.

The particle size of the carbide powder is 75-3o from the viewpoint of promoting sedimentation in the molten metal and the performance of the resulting composite casting.

The box surface of the μ method is preferable, and there is no particular limit to the shape of the particles; for example, □ crushed □ grains with rich irregularities □ are also preferably used. : □ If you preheat the bowl and put it in one pot, then when administering it at a temperature higher than □, the carbide is easily oxidized by heating and is insufficient. □ For example, to prevent oxidation.゛□An effective measure is to cover the surface of the grain with a protective film such as electroless three-gel plating.

On the other hand, metals such as cobalt (C,0) and nickel (
Examples include Ni), iron (Fe), Co-based alloys, Ni-based alloys, Fe-based alloys, etc., and are selected depending on the intended use and usage conditions of the composite casting.

All of these metals have good wettability to the carbide and form a composite phase that is strongly bonded to the carbide particles.

The production method of the present invention does not require any other special conditions. The mold used is as exemplified above.

However, the casting may be carried out by heating to an appropriate temperature, for example, 500° C. or higher, as required. The ratio of carbide particles to metal in the composite phase formed can be limited to a desired value by appropriately selecting, for example, the shape, particle size, particle size distribution, specific gravity, etc. of the carbide particles.

Next, examples of the present invention will be described.

EXAMPLE Using a casting apparatus as shown in FIG.
At the same time, preheated tungsten carbide (W2C) powder (with electroless nickel-boron (Ni-B) on the particle surface) is injected into the hopper from the loading M(7). The mixture was poured into the molten metal and cast into the mold (1).

Note that the administration of the carbide powder started at the same time as the start of pouring the molten metal, and ended when the total amount of the molten metal was poured. The dosage is determined by experience so that the ratio of metal:carbide powder in the composite phase formed in the product part in the mold is ＼'30.
This was determined taking into consideration that the ratio would be near 0 (volume ratio). Details of the casting conditions are as follows.

(A) Mold The mold (firing mold) (1) was placed in the case (3) together with Panxand (2) and preheated to 950°C in the furnace. The temperature of the mold product parts (1 and 2) during casting is 85,000.
″′r: There was.

Mold dimensions (see Figure 5): Height of the top (l/1) di
) 150 mm, height of product part (1/2) n2) 100 scale, upper diameter (dl) 120 mm, product part diameter (d2) 80
you.

(B) Gold FA (d)/-d cast iron) (1) Chemical composition (wt%): C8,38%, 5iO
176%, Mn0.68%, Ni4.41%, CrL5
7%, Mo 0.38%, remaining W Fe 0 (11) Casting flea: 9,7 kq (ii+) Casting temperature: 1610°C (C') Carbide powder (W2C powder) (1) Particle size 2 150-250 μm (it)Ni-B plating thickness: approx. 1. Q71m (output) Preheating temperature: 500°C (1v) Dosage ql: 6.1 kq A cast body having the shape shown in Fig. 8 was obtained by the above casting,
The upper metal phase portion (C-1) consisting essentially of metal was cut and removed, and the lower composite phase portion (C.2)'f: was collected as a product (composite casting). The volume ratio of metal:carbide in the obtained composite casting was 82:68, and the hardness was HItA.
It was 86. The metal structure is shown in FIG. It can be seen that the carbide particles are densely and uniformly distributed, the surface of each particle is completely coated with metal, and the interstices between the particles are filled with metal, so that they are firmly bonded.

As described above, according to the present invention, a casting having a composite phase in which carbide particles are densely and firmly bonded via metal can be obtained. In particular, the present invention does not require special equipment or conditions, and the process is simpler and more productive than, for example, powder metallurgy, and the manufacturing cost is extremely low. Furthermore, there is a large degree of freedom in the casting shape, and composite materials of various shapes can be obtained as desired, from large to small objects, and the machining allowance for subsequent machining can be small.

The composite casting obtained by the present invention is suitable as, for example, a mold material, a roll material, and other wear-resistant materials. Of course, its uses are not limited to wear-resistant applications, but can also be used for various purposes by imparting heat resistance and other mechanical and chemical properties by selecting the metal and carbide powder and controlling the composite ratio of the two appropriately. I can do it.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional explanatory diagram showing a concrete example of the final casting process, and Fig. 2 (I) and (1) show the mixture of carbide particles in the metal molten metal in the mold over time. Schematic representation of change
Fig. 3 is a vertical cross-sectional view of the cast body;
Figure 4 is a group of composite castings! & is schematically shown! Uzu,
Figure 5 is! Vertical section diagram FJ'1 showing an example of the shape of the mold, No. 6
The figure is a photograph substituted for a drawing showing the structure of a composite casting under an optical microscope. I: Casting (, 4: Hopper, 7: Carbide charging device 7/f
, M: metal, P: carbide particles. Agent Patent Attorney Miyazaki Shin 8th Department = 327- Figure 6 □ Proceeding Amendment 1, Indication of Matters, 1982 Patent Disclosure 14.31'2・Oi2,
Title of the invention: Method for manufacturing composite casting. 3. Person making the amendment ・Relationship with the case Patent applicant 44, Agent 5, Date of amendment order (voluntary) (1) On page 6, line 11 of the specification fee, after “It will be minted”, write the following information: Added, ``Injection of the molten metal and powder into the mold may start and end at the same time, or the start and end times of each may be similar to each other.In short, 1. The two are sufficiently combined in the mold, the surfaces of the carbide particles are covered with molten metal, and the carbide particles are sufficiently settled and aggregated in the product part at the bottom of the mold, and the gaps between the aggregated particles are filled with molten metal. 5 points of the Ta-shaped gate, so that it can be done! You just have to control it accordingly." Li, layer: □-□- ku 2) Ming a + Book i 10' Tribute 3, line '□8', Part-time job...This recarbonized material has the following correction: rwa (specific gravity 15'7, melting point '2800°C, W20
(specific gravity 17.2, melting point 2806° C.), and tungmetine carbides such as tungsten double carbide (for example, tungsten titanium double carbide). However, the specific gravity of this double carbide differs greatly depending on the composition, for example, tungsten titanium double carbide. (3) On page 11, line 5 of the specification, the following information is added next to "Selected." [For example, as for iron-based alloys, □
Low-alloyed cast irons, including the more Nihard cast irons shown,
Various types of high-alloy cast iron and cast steel are used. Jo...
9) Mei No. 13 WT line 5, ``Product''
□Corrected to "roll-shaped (cylindrical) product". (hereinafter “2”) □ □

Claims (1)

[Scope of Claims] (1) Molten metal and carbide powder having a higher specific gravity than the molten metal are cast in a mold, and the carbide particles are precipitated due to the difference in specific gravity. A metal phase consisting only of molten metal and a composite phase consisting of a mixture of molten metal and carbide particles are formed and solidified, and after solidification, the metal and metal phase portions are cut and removed, and the composite phase portion is made into a product. A method for producing composite castings characterized by obtaining □.
- (2) The above-mentioned (1), characterized in that the introduction of the carbide powder starts at the same time as the start of casting of the molten metal, and ends by the time when 4/'5 of the total amount of the molten metal is cast.
A method for manufacturing a composite casting as described in section. (3) Item (1) t or item (2) above, characterized in that carbide powder is added in an amount such that the volume ratio of metal to carbide particles in the composite phase portion is 1 = 1 to 1:3. 6 (4) The method for manufacturing composite castings described in Item □ (1) above, characterized in that the casting amount of the metal molten metal and the amount of carbide powder input are in a weight ratio of 2:1 to 5:1. The method for manufacturing a composite casting according to any one of Items 1 to 3. (5) The method for producing composite iron i according to any one of Items (1) to (4) above, characterized in that the mold is preheated. □ (6) Method 0 for manufacturing a composite casting according to item (5) above, characterized in that the preheating temperature of the mold is 500°C or higher.
' □ (7) Any one of the above paragraphs (1) and (6), characterized in that the carbide powder is preheated.
Method of manufacturing the described composite article. (8) The method for manufacturing composite casting □ according to item (7) above, characterized in that the preheating temperature of the carbide powder is 300°C or higher □ - (9) The carbide powder is coated with nickel-based plating. Article 2 (7) or (8)
) The method for manufacturing composite castings described in section 2. □00
Gold i (iron, nickel □ or cobalt, iron-based alloy, nickel-based alloy, or 1, cobalt-based alloy as a sign of 1-description (1) does not exist.
□No. (9) Item ゛・I, Shifting Force<L〉 (Described composite iron, Monotono East: Construction...:,, -, 0π° (Is4'l
a・ny', ;=;薯９::Q, f''>';y2,
4451.・The method for producing a composite casting according to item 1, characterized in that it is made of titanium carbide. 0 □The specific gravity of tungsten ditankerite is 10~
17.2”--The method for producing a composite casting according to item (11).