JP5964639B2 - Amorphous alloy plastic working method and plastic working apparatus - Google Patents

Description

  The present invention relates to a method and an apparatus for plastic working an amorphous alloy (including metallic glass, including those having a non-amorphization rate of 100%), and forms an amorphous alloy by injection on a preheated substrate. Immediately after that, the amorphous alloy is plastically deformed by, for example, rolling with a grooved roll.

  Although amorphous alloys have many excellent performances such as corrosion resistance, wear resistance, soft magnetism, and catalytic properties, they have not been widely developed as industrial members. One of the reasons is that it hardly plastically deforms.

  Regarding plastic deformation of metallic glass, which is a kind of amorphous alloy, there are the following prior art documents.

Akihisa Inoue: Material Science and Engineering of Bulk Metallic Glass Toru Yamazaki: Creation of high-strength metal-based nano-micromaterials through mesoscale structure control

  An amorphous alloy has large elastic deformation and high breaking strength at room temperature, but has almost no plastic deformability, and has a drawback that it easily undergoes structural relaxation or crystallization and brittle fracture even at elevated temperatures. On the other hand, when the metallic glass is heated to the glass transition temperature, it becomes a supercooled liquid Newtonian viscous state, and can be uniformly formed at a low strain rate and applied to various products (the above non-patent document). 1). Amorphous alloys have superior properties such as higher strength, higher soft magnetic properties, and higher corrosion resistance than metallic glass, so if they can be plastically processed, they will be applied to more industrial materials. However, at present, even if an amorphous alloy having the characteristics of high strength, low Young's modulus, and high elastic limit strain is plastically deformed, there is almost no elongation and it cannot be solved. Therefore, plastic processing is performed by reheating a metal glass prepared by a single roll method or a sputtering method to form a supercooled liquid state or by nanocrystallization (Non-Patent Document 2).

  An amorphous alloy that is not metallic glass cannot be plastically processed by the same method as metallic glass because the temperature range in which it is in a supercooled liquid state is extremely narrow. Such an amorphous alloy is manufactured by rapidly cooling a molten metal. However, even if an amorphous material that has undergone a rapid cooling process is heated and heated again from room temperature, it does not enter a supercooled liquid phase state. Therefore, it is impossible to carry out plastic processing in an amorphous state. Conventional methods for producing amorphous alloys (so-called single roll method, twin roll method, etc.) are those that rapidly cool molten metal to room temperature, so that even if the manufactured amorphous alloy is heated, it remains amorphous. It cannot be ready for plastic working.

  The present invention provides a method and apparatus that enables plastic working even for amorphous alloys other than metallic glass.

  The present invention forms an amorphous alloy film by spraying (spraying) on the surface of a heated substrate, and immediately after that (for example, after the time when the amorphous alloy is cooled to below the crystallization temperature). While the amorphous alloy does not fall below a temperature range having plastic fluidity, the film is subjected to compression processing (including pressing and rolling).

As described above, with the exception of metallic glass, an amorphous alloy does not enter a supercooled liquid phase even when heated to an elevated temperature, and cannot be plastically processed. However, when an amorphous alloy film is formed on a substrate by spraying (spraying), immediately after the formation, the temperature near the glass transition temperature is cooled relatively slowly while the film still does not drop to room temperature. Time zone can be provided. The inventors have made a hypothesis that the amorphous alloy may be compression-processed in the temperature range of the time zone, and have conducted a test and have arrived at the present invention.
That is, if the amorphous alloy film is cooled slowly below a predetermined temperature (near the crystallization temperature) by heating the base material to be sprayed, the amorphous alloy is plastically flowed in the above-mentioned time zone. It can be kept for a while in the temperature range. If compression processing was performed during that time, it was confirmed that the amorphous alloy film could be plastically deformed as hypothesized.
According to this method, the amorphous glass (non-metallic glass), which has the characteristics of high strength, low Young's modulus, and high elastic limit strain at room temperature, is extremely narrow in the supercooled liquid state. It becomes possible to perform plastic working in the same manner as in FIG. The amorphous alloy film that has been subjected to plastic working can be peeled off from the base material later, or can be made into a final product or an intermediate product in the previous stage together with the base material without being peeled depending on the application.

In the processing method of the invention, it is desirable that the amorphous alloy is compressed as described above while it is in a temperature range having plastic fluidity and immediately below the glass transition temperature.
This is because the amorphous (amorphous) alloy does not change to crystalline unless it is directly below the glass transition temperature and exceeds the crystallization temperature.

In particular, metal powder is sprayed and melted with a flame by a spray gun, and cooled by a cooling gas (including mist) before the flame reaches the base material (that is, such gas-cooled thermal spraying). The above injection should be performed (using a gun).
It is difficult to make the molten metal particles amorphous by spraying and melting metal powder together with the flame, but as described above, the flame before it reaches the base material is cooled with a cooling gas. If injection is performed, it is easy to rapidly cool the molten metal particles to a predetermined temperature to make them amorphous. Therefore, according to this method, it is possible to smoothly carry out the plastic working by forming an amorphous alloy film that is not metal glass on the substrate.

It is advantageous to use a metal thin plate as the base material and perform compression rolling with a grooved roll as the compression processing. The “groove” of the grooved roll includes various concave portions (and convex portions adjacent thereto), and therefore the “grooved roll” includes irregularly shaped rolls of all shapes.
When an amorphous alloy film is formed on the surface of a substrate that is a thin metal plate by spraying, and the amorphous alloy film is passed through a rolling mill with the substrate, the amorphous plastic film is continuously plasticized. Processing can be performed. The thin metal plate as the base material may not be separated depending on the use, but may be separated from the amorphous alloy film as shown below.

It is also preferable to peel the amorphous alloy film from the base material simultaneously with the compression processing or after the compression processing.
When the amorphous alloy film is peeled off, it is generally easy to use it for various purposes thereafter. In order to peel the amorphous alloy film from the base material, it is preferable to apply or spray a separating agent on the surface of the base material before the jetting. Further, when a metal thin plate is used as a base material, if a different diameter single-drive rolling mill in which the upper and lower rolls have a diameter difference and only one of the upper and lower rolls is driven during rolling is used, The film is easy to peel from the material.

In the present invention, for example, an amorphous alloy film of Ni72-Mo4.5-Nb10-B13-Cu0.5 (% Atom) is formed on the surface of a heated metal thin plate by spraying, and the amorphous alloy is heated to a temperature of 300 ° C. to 500 ° C. In this state, it is preferable to carry out compression rolling with a load of 10 tons or more within 7 seconds after the injection.
Thereby, plastic processing of the amorphous alloy film of the above components can be performed.

In order to perform the above-described plastic working method, an apparatus including a supply means for the metal thin plate, a preheating means for the metal thin plate, an injector for forming an amorphous alloy film, a rolling mill, and a temperature control means for the amorphous alloy film is used. It is good to do.
If such an apparatus is used, a series of processes in which an amorphous alloy film is formed on the surface of a thin metal sheet to be supplied and preheated by spraying, and then the film is subjected to compression rolling with a grooved roll to plastically process the film is smoothly performed. Can be realized.

  According to the present invention, an amorphous alloy sheet can be plastically deformed and processed into a final product shape, or the final product can be preformed.

It is a schematic diagram which shows formation of a jet film, and compression rolling by a grooved roll. A schematic diagram showing the shape of the groove by displaying the surface of the grooved roll in a flat plate shape is appended to the left side. It is a side view which shows a large sized quench transition control injector. It is a whole side view of a plastic working apparatus. It is measurement data which shows the operation performance of amorphous alloy injection and channel rolling. It is each external appearance photograph of the amorphous alloy thin plate (those which are not metal glass. Photograph left side) rolled with the grooved roll, and the similarly rolled metal glass thin plate. It is an optical microscope photograph of the cross section of the amorphous alloy thin plate rolled with the grooved roll. It is a chart which shows the roughness of the amorphous alloy thin plate (the surface and back surface) and base material (the surface) rolled with the grooved roll.

  If the developed ultra-quenching transition injection technology is utilized, there is a possibility that the amorphous alloy can be plastically processed at a high temperature near the glass transition temperature immediately after injection. Therefore, we tested for the first time in the world whether plastic deformation could occur by rolling, which is a compression process, near the glass transition temperature. In general, the crystallization temperature refers to a temperature at which the amorphous transitions to a crystallized state during heating, but means a temperature at which the amorphous transitions from a supercooled liquid to a crystallized state during cooling. On the other hand, the glass transition temperature generally refers to the temperature at which the amorphous state transitions to the supercooled liquid during heating, and indicates the temperature at which the supercooled liquid becomes amorphous during cooling.

  Figure 1 shows the amorphous alloy semi-melt compression rolling method using a grooved (grooved) roll mill. The semi-molten metal sprayed onto the base material on the entrance side of the rolling mill is bitten into the rolling mill at a high temperature of 300 ° C. to 500 ° C. to give a groove shape. The work roll is made of roll bearing steel and has a diameter of 125mm both above and below. Assuming a fuel cell separator as the final product, the upper work roll was provided with 53 grooves in the width direction with a groove width of 1.0 mm, a peak width of 1.0 mm, a depth of 0.6 mm, and a length (circumferential direction) of 121 mm. In order to investigate the influence of the strength of the base material, two types of SS400 having a tensile strength of 400 MPa and SPHC having a tensile strength of 300 MPa were used. The injected material is Ni72-Mo4.5-Nb10-B13-Cu0.5 (% Atom), an amorphous alloy, and the crystallization temperature is 520 ° C. If it is rolled below 500 ° C, crystallization can be prevented.

  The apparatus of the present invention is a continuous production equipped with a large ultra-quick transition control injector (that is, an injection device. Cooling capacity: more than 1 million degrees per second. Fig. 2) that enables the production of amorphous alloy with a thickness of 300 µm or more. Equipment (FIG. 3). 2 has a plurality of material injection holes arranged at equal intervals in the width direction (perpendicular to the paper surface), and gas injection holes on the outer side (left and right sides of the paper surface). A gas gun that has a structure in which gas is injected as a flame to melt the material and is cooled rapidly with water mist, etc., and the material is injected uniformly in the width direction, so that a thin plate with a uniform thickness in the width direction can be formed It is.

The large ultra-quick transition control injector of FIG. 2 is configured as follows. That is,
a) In order to make the cross-section of the flame 1 containing material particles horizontally long (approx. 300 mm in width), each spray connected to the material particle injection port 5 and the flame injection ports 6 and 7 (on the front surface (bottom surface)) A plurality of mouths) are continuously arranged along a straight line in the width direction.
b) Nitrogen gas (inert gas) 2 injection ports 8 for rectifying and cooling the flame 1 at positions on both sides of the material particle injection port 5 and the flame injection ports 6 and 7 along the straight line. A plurality are continuously arranged.
c) At the positions on both sides of the material particle injection port 5, the flame injection ports 6 and 7 and the inert gas 2 injection port 8, the injection port 4 of the water mist 3 for cooling the flame 1 is connected to the straight line. The mist nozzle is provided as a slit along the line.

The angle of the injection port 4 of the water mist 3 is determined so that the mist 3 to be injected approaches the flame 1, and the angle can be changed according to the chemical composition of the material particles. Moreover, the injection pressure of the nitrogen gas 2 and the water mist 3 can be changed similarly. Due to the action of the nitrogen gas 2 and the water mist 3, the cooling rate of the flame (flame including material particles) 1 reaches 400,000 to 1 million ° C./second.
The water mist 3 is decomposed into oxygen and hydrogen by contact with the flame 1 with a high thermal power, and the amount of oxygen in the flame 1 is reduced so that the amount of oxygen injected from the flame injection port 7 is reduced. , 50-80% of the amount of oxygen required for complete combustion.

A facility for continuously plastic working an amorphous alloy film is shown in FIG.
This equipment forms an amorphous alloy film on the surface of a metal thin plate substrate by thermal spraying, then rolls it with a grooved roll, and then peels the amorphous alloy film (thin plate) that has been plastically deformed from the thin plate substrate. To collect. This facility will be described in detail below.

The basic equipment and functions of the equipment shown in FIG. 3 are as follows.
Payoff reel 11: For receiving a thin base coil.
Surface polishing device 12: Abrasive material is sprayed onto the surface of a substrate using compressed air produced by a compressor.
Separating agent application and spraying device 13: A device for applying a separating material to facilitate separation of the amorphous alloy thin plate and the thin plate base material. It may be provided between the thin plate base material heating device 16 and the ultra rapid cooling transition control injector 17.
Preheater 14: Heats the thin plate substrate from room temperature to about 350 ° C. This time, two rows of propane burners were arranged in the width direction.
Leveler 15: This corrects the shape collapsed by heating the thin plate substrate.
Thin plate substrate heating / soaking device 16: Heats the thin plate to 200-500 ° C. When the thin plate heating temperature is lower than 200 ° C., when rolling an amorphous alloy produced by injection, the plastic fluidity is insufficient and the amorphous film is cracked. On the other hand, when the thin plate base material is heated to a temperature higher than 500 ° C., an amorphous alloy film is not generated because the molten alloy powder becomes higher than the crystallization temperature at the time of injection by a large ultra-quick transition control injector. The equipment here adopted an infrared system.
Large super rapid transition control injector 17: Amorphous alloy film production device that forms the basis of the production of amorphous alloy film and amorphous alloy sheet. The configuration and the like are as described above (see FIG. 2).
Dust collector 19: A dust collector installed on the front face of the rolling mill collects the residual powder of the amorphous alloy after the injection and recovers the surplus gas used in the large-scale ultra-quenching transition control injector. The gas energy used to melt the amorphous alloy powder is less than 10% of the total. Therefore, if the surplus gas is not recovered, the ambient temperature around the rolling mill is 450 ° C., the surface of the amorphous alloy film on the thin plate substrate is 600 ° C. or more, and the amorphous film starts to crystallize. Since the inside of the dust collector becomes hot because a large amount of gas is collected, the dust collector and the piping before the dust collector are cooled with water mist and the temperature inside the dust collector is controlled to be 80 ° C or lower. Hoods for dust collection are provided at the left and right of the passage position of the thin plate base material and at the position surrounding the upper part of the rolling mill, and water mist for cooling is sprayed toward them. Water mist for cooling is also injected into suction ducts connected to each dust collection hood, and suction gas is sent to the dust collector body through the ducts.
Groove roll rolling machine 18: An amorphous alloy film is pressed together with a thin plate base material to perform groove-shaped plastic working. It also has the effect of crushing consistent holes and vacancies in the amorphous alloy film and increasing the surface smoothness.
Thin plate substrate winder 20: Winds the thin plate substrate separated from the amorphous alloy film.
Amorphous alloy thin plate winder 21: Winds the separated amorphous alloy film as a thin plate.

The following facilities may be added to the illustrated facilities. That is,
Amorphous alloy thin plate heating device: A device for holding a separated amorphous alloy thin plate in the plastic flow temperature range.
Warm processing machine: A machine that further processes and molds an amorphous alloy sheet kept at a plastic flow temperature.

The plastic working of the amorphous alloy sheet using the apparatus shown in FIG. 3 is performed as follows.
That is, first, the thin plate base material is placed from the payoff reel 11 to the tension reel (winding machine 20), the payoff reel 11 is activated, and the thin plate base material is fed from the left to the right in the drawing. The thin plate substrate to be fed is subjected to surface polishing or application of a separating material, preheated and corrected in shape, heated and soaked to a predetermined temperature, and an amorphous alloy film is formed by the large super rapid cooling transition control injector 17.
Immediately thereafter, the amorphous alloy film and the thin plate base material are rolled by a rolling mill 18. The rolling temperature at the time of rolling is a plastic fluid region (temperature of 300 to 500 ° C.) regardless of whether the alloy film is amorphous (not metallic glass) or metallic glass. The rolling reduction is 10 to 50% of the thickness of the amorphous alloy sheet, and the rolling speed is 2 to 20 m / min. The surface temperature of the amorphous film is measured with a thermocouple or the like, and the heating of the thin plate substrate is controlled by the preheater 14 or the heating / soaking device 16 accordingly.
After rolling, the separated thin plate base material and amorphous alloy thin plate are wound up by winders 20 and 21, respectively. Further, an amorphous alloy thin plate preheating device and a warm processing machine may be placed in front of the amorphous alloy thin plate winder to further plastically process the amorphous alloy thin plate.

  FIG. 4 shows a chart relating to the rolling entry temperature, rolling exit temperature, load, and the like. SS400 with a plate thickness of 2 mm is passed as a base material with a roll gap of about 1.8 mm, and the rolling load at that time is 15 tons. Although the substrate surface temperature before jetting measured by the contact temperature type is not stable, it is generally constant at 300 ° C. from the results. Injection was performed until the temperature of the exhaust gas increased and decreased, and the amorphous alloy was compressed and rolled with a grooved roll in about 5 seconds after injection of about 300 μm. The rolling load before injection is 15 tonf, and the rolling load during injection is increased up to 25 tonf to 30 tonf. The reason why the rolling load increases with time is considered to be that the roll is heated and expands. It can be seen that the rolling exit temperature (film temperature after rolling) is substantially constant 310 ° C., and rolling is performed at a temperature lower than the glass transition temperature.

  FIG. 5 shows the appearance of the amorphous alloy film after groove roll rolling, and it can be seen that the film is beautifully compressed and deformed into a groove. As a feature, not only the amorphous film but also the groove shape is deformed up to the base material, and a phenomenon generally called transfer occurs. When comparing two types of base materials, SS400 with a tensile strength of 400 MPa and SPHC with a tensile strength of 300 MPa, it was confirmed that the groove of the amorphous film after channel rolling becomes deeper when soft SPHC is used as the base material. However, since SPHC is soft, it is necessary to perform profile control to suppress the elongation in order to obtain a sample with good flatness.

  FIG. 6 shows an optical micrograph of the amorphous alloy film (cross section separated from the substrate) that has been groove-rolled as described above. A good quality amorphous film is formed even when rolling with high load.

  Since the groove depth and shape of the amorphous film after rolling were not clear in the optical micrograph shown above, the groove depths on the front and back surfaces of the amorphous alloy film and the surface of the base material SS400 were measured with a roughness meter as shown in FIG. It was. The groove depth was 0.07 mm on the surface of the amorphous film, 0.05 mm on the back surface, and 0.07 mm on the base material SS400. Since the groove depth attached to the roll is 0.6 mm, there is a possibility that the amorphous alloy is not completely filled during rolling or is spring-backed after rolling. This is because the surface of the amorphous alloy has a lower roughness than the back surface. Further, the groove depth on the amorphous back surface is 0.05 mm, which is smaller than the groove depth of the base material 0.07 mm.

Conventionally, it has been considered that amorphous alloys have almost no plastic deformation ability because they are not viscous and have only a few percent elastic deformation below the glass transition temperature. However, from this result, there is a possibility of a new phenomenon that the amorphous alloy has viscosity even below the glass transition temperature. Since the conventional amorphous alloy manufacturing method rapidly cools to room temperature, the fluidity and plastic deformability immediately after the formation of the amorphous alloy cannot be investigated. However, the fluidity and plastic deformability immediately after the formation of the amorphous alloy could be investigated for the first time by the process of plastic deformation by rolling immediately after injection performed by the inventors.
When the amorphization rate of the above-mentioned grooved rolled material is measured by DSC, it is as high as about 80% and is sufficiently amorphized during jet quenching. That is, the possibility of being in a supercooled liquid layer state higher than the glass transition temperature during the groove rolling is small.
The principle that plastic processing of amorphous alloys, which was said to be impossible in the past, was achieved by applying semi-molten rolling compression immediately after forming an amorphous alloy film with a super-cooled large transition control spray gun. It is presumed that the supercooled liquid layer is brought about when the surface layer is heated by being strongly pressed in the elastic region of the amorphous alloy just below the transition point.

14 Preheating machine (preheating means)
16 Heating and soaking equipment
17 Injection machine
18 Rolling mill
20, 21 Winder

Claims (7)

Forming an amorphous alloy film on the surface of the substrate by spraying, and immediately after that, compressing the film while the amorphous alloy does not fall below the temperature range of plastic fluidity ;
And heating the base material before the injection so that the film does not fall below the temperature range having composition fluidity from the time of the injection to the time of compression processing and does not exceed the crystallization temperature. A method for plastic processing of an amorphous alloy. 2. The amorphous alloy according to claim 1, wherein the metal powder is injected and melted together with a flame by a spray gun, and the injection is performed by cooling with a cooling gas before the flame reaches the base material . Plastic working method. 3. The amorphous alloy according to claim 1 , wherein the amorphous alloy film is prevented from reaching a crystallization temperature or higher by sucking surplus gas generated by the jetting before compression processing and sending the gas to a dust collector. Plastic processing method.   The method for plastic working an amorphous alloy according to any one of claims 1 to 3, wherein a metal thin plate is used as the base material, and compression rolling is performed by a grooved roll as the compression processing. Before the jetting, a separating agent is applied or sprayed on the surface of the base material, and when performing the compression rolling, the upper and lower rolls have a diameter difference and only one of the upper and lower rolls is driven. The method of plastically processing an amorphous alloy according to claim 4, wherein the amorphous alloy film is peeled from the substrate by using a machine .   An amorphous alloy film of Ni72-Mo4.5-Nb10-B13-Cu0.5 (% Atom) is formed on the surface of the heated metal sheet by spraying, and the amorphous alloy is maintained at a temperature of 300 ° C to 500 ° C. The method for plastic working an amorphous alloy according to any one of claims 1 to 5, wherein the compression rolling is performed with a load of 10 tons or more within 7 seconds after the injection. It is an apparatus for the plastic working method according to any one of claims 4 to 6 , wherein said thin metal sheet supplying means, said thin metal sheet preheating means, an injector for forming an amorphous alloy film, a rolling mill, an amorphous material An amorphous alloy plastic processing apparatus comprising temperature control means for an alloy film.