JPS61117003A - Highly hard material type tool and manufacturing method thereof - Google Patents

Abstract

PURPOSE:To make improvements in strength, abrasion resistance and tenacity, by constituting it in a way of putting a work part consisting of a highly hard material and a support part consisting of a highly strength material solidly together by means of homogeneous joining via a joining surface, in case of a press metal mold punch or the like. CONSTITUTION:A punch tip molding part 1, manufactured with a sintered hard alloy or ceramics composed of more than one type of a carbide, a nitride, a carbon nitride, boride and a silicide of periodic table 4a, 5a, 6a group metals and more than one type of bond metals of Fe, Co, Ni, etc., and a punch shank part 2 are vacuum-brazed at a joining surface via a brazing material 11 of Cu, Ni systems, etc., and then high temperature hydrostatic pressure applied homogeneous joining takes place. And, otherwise, they are joined together together by means of vacuum hot press homogeneous joining, electron beam welding, cam cell type HIP homogeneous joining, vacuum hot press joining, etc. With this constitution, abrasion resistance, strength and tenacity are all improvable.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention is applicable to high-hardness materials (periodic table 4a, Sa, 6a
One or more of group metal carbides, nitrides, carbonitrides, borides, or silicides and a combined metal (mainly Fe, Co.

The present invention relates to a tool in which a processing part made of cemented carbide made of one or more types of Ni) or ceramics) and a support part made of a high-strength material (tool steel, special steel, etc.) are joined and integrated.

(Prior Art) Tools are required to have excellent properties such as strength, wear resistance, and toughness. As materials for tools, high-strength materials (tool steel, special steel, and other steels suitable for tools) and high-hardness materials (cemented carbide and ceramics) are used. The former has excellent toughness, and the latter has excellent hardness (wear resistance).
It is inherently difficult to obtain a material with excellent properties of both toughness and hardness. Conventional tools are either processed products of tool steel, special steel, etc., or are integrally molded products of cemented carbide, and the material is selected depending on the purpose of wear resistance, impact resistance, cutting, etc. It's here. In addition, a hardened layer is further formed on the surface of the steel by a surface hardening treatment method, and a tool with excellent properties in both toughness and hardness is manufactured.

As an example of a tool, manufacturing of a press die punch for cold forging, warm forging, and hot forging will be described. tool steel,
Materials such as special steel are processed into punch shapes by cutting, etc., and heat treated to give them toughness and hardness (800 to 1260
C hardening and tempering at 100 to 570 C), finish polishing or finish cutting the material, and then add C to the tool surface to further improve wear resistance.
A surface hardening treatment method is applied to form a hardened layer using the VD method, and then heat treatment (quenching at 800-1260°C and ioo-570°C
The hardened coating layer formed by CVD treatment (tempering) has high hardness and has poor affinity with iron-based materials, thereby reducing its frictional resistance.

(Problems to be solved by the invention) Conventional tools are either processed products of tool steel, special steel, etc., or are integrally molded products of cemented carbide, so when used, problems due to the characteristics of the materials occur. will occur. For example, the disadvantage of punches for press molds made of conventional materials (tool steel, special steel, etc.) is that the tip of the punch (processed part) undergoes high repeated compressive stress during forging.

As it is subjected to thermal shock, friction with the material to be forged, etc., the tip of the punch may suffer from vertical cracks, horizontal cracks, peeling, and permanent deformation due to insufficient strength, insufficient hardness, material segregation, etc.

Damage such as breakage and abrasion is likely to occur. On the other hand, punches for press molds that have been subjected to surface hardening treatment that goes beyond conventional methods,
The base material, such as tool steel, undergoes plastic deformation due to stress during forging in the initial stage of forging, which causes cracks in the surface hardened layer and causes peeling of the hardened layer as forging progresses, resulting in easy wear and seizure6. Therefore, the excellent wear resistance of the hardened coating layer cannot be fully realized, the desired tool life cannot be obtained, and process losses such as mold replacement occur.

Furthermore, due to variations in the quenching state of the tool steel base material during heat treatment, there were large differences in tool life even under the same forging conditions.

Although cemented carbide materials have high hardness, they are brittle compared to tool steels, etc. Therefore, punches for press molds made of cemented carbide materials are manufactured by using a precision press machine (Kai) to reduce tensile and bending stress. It cannot be used unless the stress state conditions do not occur, and the conditions of use are very restricted.

An object of the present invention is to provide a tool that is excellent in strength, wear resistance, and II properties, and a method for manufacturing the same.

(Means for solving the problem) In the present invention, by joining a high-hardness material such as cemented carbide and a high-strength material such as tool steel to take advantage of the advantages of both materials, 1) the material Solve the problem of selection constraints.

In the high-hardness material welding type tool according to the present invention, a machining part that contacts a workpiece to perform machining and a support part that supports this machining part are integrally diffusion-bonded via a joint surface, and the above-mentioned machining is possible. part is made of a high-hardness material, the support part is made of a high-strength material, and if necessary, the surface of the processed part,
At least a portion of the surface of the support portion that is continuous with the surface of the processed portion is coated with a hardened layer.

Furthermore, the method for manufacturing a high-hardness material welding tool according to the present invention includes:
A diffusion material is interposed and fixed between the surface of the processed part material to be joined and the opposing surface of the support part material to be joined,
Next, all of this diffusion material is diffused through both surfaces under pressure, and the processed part material and the support part material are directly diffusion-bonded at the bonding surfaces, with the processed part made of a high-hardness material and the support made of a high-strength material. (Function) The tool for welding high-hardness materials according to the present invention is required to have high wear resistance, hardness, etc. The processing part uses high hardness material,
By using a high-strength material for the support part that requires high toughness, the advantages of both materials can be utilized.

Further, in the method for manufacturing a high-hardness material joining type tool according to the present invention, a diffusion material is diffused into the processing portion and the support portion under pressure to integrally diffusion bond the processing portion and the support portion.

(Example) Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIGS. 1(a) to (d) show a cross section of a punch for a press die. During manufacturing, the punch shape and mold.

The joint position and joint surface shape are designed based on the shape of the forged product, forging material, calculated stress, etc., resulting in high wear resistance and heat resistance.

A high-hardness material (cemented carbide, ceramics) is used for the punch tip molding part 1, which requires compressive strength, and a high-strength material (tool steel, etc.) is used for the punch shank part 2, which requires strong toughness. Both joining members 1 and 2 are prepared with dimensions including finishing machining allowance, and the roughness of the joint surface 3 is 100 μm or less. Here, (a), (c), and (d) are punches for punching. In addition, in the punch for punching (c) + (d), the joint surface 3 is concave or conical to widen the joint surface. On the other hand, (b) is a punch for drawing, and the length of the punch tip is made longer than the length of other punches to improve the wear resistance of the surrounding area that comes into contact with the workpiece. We are trying to

When bonding, the bonding surface 3 is cleaned and removed by 1) impurities such as surface oxides by pickling and degreasing, and then both members 1 and 2 are combined and bonded using one of the bonding methods described below. Implement. Finally, the final shaped product is molded.

Next, the joining method will be explained with reference to FIGS. 2 to 5.

■ Vacuum brazing properties (see Figure 2) (a) Tip part (high hardness material) 1 and shank part (tool #
4) Charge a Cu-based or Ni-based brazing filler metal 11 to an arbitrary thickness into the joint between 2 and 2, and (b) vacuum braze at a predetermined temperature for several minutes to several tens of minutes. (c) High temperature isostatic pressurization (
HIP) diffusion bonding (800-1200℃, 200-10
00 atm) or vacuum hot press diffusion bonding (800 atm)
~1200°C, 200~1000 atm) 6 However, the thickness of the brazing filler metal 11 is as follows:
The thickness is selected such that it completely diffuses and penetrates into the bonding members 1 and 2, and cannot exist in a single phase between the bonding members 1 and 2 after bonding. Furthermore, the brazing filler metal 11 must not form a brittle intermediate compound with both joining members 1.2 during the diffusion joining process.

(■ Electron beam welding method (see Figure 3) (a) Tip (
Insert an insert metal 112 such as N1 of an arbitrary thickness into the joint between the high-hardness material) 1 and the shank part (high-strength material) 2, or (b) electron beam welding of the peripheral edge 13 of the joint part to vacuum seal the joint surfaces; (c) then HIP diffusion bonding (1000-1300°C, 20°C) of both members 1 and 2;
0-1000 atm) or vacuum hot press diffusion bonding (1000-1300°C, 200-too much).

Atmospheric pressure). However, the insert metal 12 must not form a brittle intermediate compound with both joining members 1 and 2 during the joining process.

■Capsule method HIP diffusion bonding method (see Figure 4) (a)
Tip part (high hardness material) 1 and shank part (high strength material) 2
(b) Insert an insert metal 12 of N1 or the like of arbitrary thickness into the joint between The pressure medium particles 14 and the tiger were vacuum-sealed in a mild steel capsule 15, and (c) HIP diffusion bonding (1000 to 1300°C, 2
00 to 1000 atm). (Capsule method HIP
For details, see Japanese Patent Application Laid-open No. 163699/1983).

■ Vacuum hot blurring method (@see figure 5) (,) tip (
Insert metal 12 such as Ni of any thickness into the joint between the high-hardness material) 1 and the second part (high-strength material) 2, or join both the tip part 1 and the shank part 2. The surfaces are brought into direct contact, and (b) vacuum hot press diffusion bonding (1000-1300°C, 200-1000 atm) is performed thereon.

) Furthermore, if necessary, a hardened layer is applied after carrying out the above bonding method in order to improve the wear resistance.

In other words, the punch surface for press molds.

1: cVD treated El (800-1200° C.) A hardened layer is deposited and coated. This hardened layer includes various carbides, nitrides, carbonitrides, borides, or silicides of transition metals, A, 9. A single layer, multiple layers, or multiple layers of Y, Zr, etc. are coated with one or both of the oxides.

■ Furthermore, in order to stabilize the surface hardened layer and obtain sufficient adhesion strength by diffusing the hardened layer to the punch base material, the above press mold punch was subjected to HIP diffusion treatment (800 to 120
0°C and 1200 to 1000 atmospheres).

Note that a method for bonding cemented carbide alloys or cemented carbide and metals by HIP, if necessary through a metal seal, is disclosed in Japanese Patent Application Laid-Open No. 75443/1982, but the method described above is Method (2) is different in that it involves an electron beam welding process. , Examples are described below. In each example, the punch shape,
The joint position, joint surface shape, joint member size, and forging conditions were all the same. FIGS. 6(a) and 6(b) are a front view and a side view, respectively, of the press die punch of this embodiment. The tip portion 1 is made of cemented carbide 63 to G4, and the shank portion 2 is made of high speed steel 5KH55.

The following (A) to (D) show a diffusion bonding method and bonding conditions between the tip portion 1 and the shank portion 2 of the punch.

(A) Using Ni base brazing material → vacuum brazing (100G-
1200℃, 10°'Torr or less) - HIP diffusion bonding (1100℃ or less, 200 to 5 tons) 0 atm) → Finishing (B) Insert metal (Ni material thickness 0.05 to 0
．． Use 1mm1 → Electron beam welding → HIP diffusion bonding (1
100~1300'C1200~1000 atm) → Finishing (C) Capsule method HIP diffusion bonding (1100~1
300°C 1200-1000 atm) → Finishing (D) Vacuum hot press diffusion bonding <1100-13
00° C., 200-1000 atm) → Finishing Further, Examples 1 to 3 below show punch processing conditions.

(Example 1) A punch is polished and finished after heat treatment.

(Example 2) A punch is subjected to CVD treatment (800 to 1200° C.) to deposit a TiC coating layer of several μm, and then heat treated.

(Example 3) CVD treatment of punch (800-1200'C)
A TiC coating layer is deposited to a thickness of several micrometers, followed by HIP diffusion treatment (1000° C. or lower, 500 atmospheres or lower), followed by heat treatment.

Cold forging was performed using a press die punch that had been bonded and treated as described above. The material to be forged is a 325C annealed material. The table shows the number of punches produced in this way. For comparison, a conventional punch was produced by processing high speed steel as a material and forming a TiC surface hardening layer, and similarly used for cold forging. As is clear from the values in the table, the life of the punch tool of this example increased by several tens of times to a stone. In addition, the tool life of Example 2, which was subjected to surface hardening treatment, was nearly twice as long as that of Example 1, which was not subjected to surface hardening treatment, and the tool life of Example 3, which was further subjected to HIP diffusion treatment, was It is even longer than Example 2.

In the tip of the example in which the number of pieces manufactured per punch is higher than that in the table, cemented carbide was used for the tip 1, but instead, ceramics such as a CBN sintered body were used for joining with the support part. It's okay. (The fact that HIP diffusion bonding between steel and ceramics is possible is
6) In this case as well, the tool life was significantly extended.

Note that the above joining method is applied not only to press molds but also to tools in general, such as cold plastic working punches such as punch punches, drawing 9 bending punches, and the like.

Examples of square and triangular cutting tips, which are cutting tools, are shown in FIGS. 7(a) and 7(b), respectively. Square or triangular support (made of tool steel) 21.
Each corner 23, 23.31 on the machined surface 22.32 side. ...
; 33, 33. . . . The cemented carbide is diffusion bonded and treated in the same manner as described above. Also in this example, the tool life was significantly extended compared to the conventional cutting tip.

(Effects of the Invention) According to the present invention, the tool life is significantly increased by several tens of times compared to a conventional punch for the following reasons.

The high-hardness material structure has a tendency to suppress the generation and propagation of microcracks compared to tool steel, etc., and the toughness is improved by HIP treatment, so the cracking resistance is improved. Furthermore, because the amount of plastic deformation of the high-hardness material in the processed part (punch tip, etc.) is small, changes in the stress distribution at the tip are suppressed.
Therefore, bending stress generated in the support portion (punch shank portion, etc.) is also reduced. Due to this longer life, process losses such as mold replacement are greatly reduced, and productivity is greatly improved.

Furthermore, for the same reason, the precision of forged products is also dramatically improved. Why 1: Cemented carbide is a high-hardness material, has high wear resistance and compressive strength due to its fiber properties, is stable against thermal shock, and is less susceptible to repeated stress during forging than tool steel etc. This is because the amount of wear and plastic deformation is small.

Furthermore, this allows the post-processing process to be omitted for products that conventionally required cutting after forging.

According to the present invention, the most effective tool can be obtained by changing the joining location and joining method depending on the application and usage conditions.

Furthermore, it is possible to manufacture tools that can process products with shapes that cannot be plastically worked using conventional methods.

Tools that have been surface-hardened on a high-hardness material base material are superior to conventional methods due to the synergistic effect of small plastic deformation of the base material and extremely stable material against heat treatment. As a result, its wear resistance can be dramatically improved.

The HIP diffusion treatment after the surface hardening treatment improves the adhesion strength with the base material by promoting diffusion of the hardened coating layer into the base material. Therefore, the possibility of peeling of the hardened layer is reduced, the wear resistance is further improved, and the tool life is increased by at least 30 to 100 times.

[Brief explanation of the drawing]

FIGS. 1(a), (b), (c), and (d) are cross-sectional views showing an example of the joint position and joint surface shape of the press die punch according to the present invention, respectively. FIGS. 2(a), (b), and (c) are explanatory diagrams of a method of joining after vacuum brazing. FIGS. 3(a), (b), and (c) are explanatory diagrams of a method of joining after electron beam welding. FIGS. 4(a) and 4(b) are explanatory diagrams of the capsule type HIP diffusion bonding method. FIGS. 5(a) and 5(b) are explanatory views of the vacuum hot press diffusion bonding method. Nos. fJfl(a) and (b) are a front view and a side view, respectively, of an example of a punch for a press die. FIGS. 7(a) and 7(b) are perspective views of embodiments of the cutting tip, respectively. DESCRIPTION OF SYMBOLS 1... Processing part, 2... Support part, 3... Joint surface, 11... Brazing metal, 12... Insert metal I, 13... Electron beam welding part, 14... Pressure medium particles, 15...capsules, 21...
Support part, 22...processed surface, 23.23. ...
... Corner part, 31... Support part, 32... Machining surface, 33.33.33... Corner part. Patent Applicant: Sun 70 Yegyo Co., Ltd. Agent: Patent Attorney: Two Idiots, Figure 2, Evening 3, Figure 4, SM No. 61!1

Claims (12)

[Claims] (1) A processing part that contacts and processes a workpiece and a support part that supports this processing part are diffusion bonded together via a bonding surface, and the processing part is made of a high-hardness material, and the A high-hardness material joining type tool whose support part is made of high-strength material. (2) In the high-hardness material bonded tool described in claim 1, the high-hardness material is cemented carbide, and the high-strength material is steel for tools. High hardness material joining type tool. (3) The high-hardness material bonded tool described in claim 1, characterized in that the high-hardness material is ceramics, and the high-strength material is steel for tools. A tool for joining high-hardness materials. (4) The machining part that contacts and processes the workpiece and the support part that supports this machining part are integrally diffusion bonded via the joint surface, and the said machining part is made of a high-hardness material, and the A high-hardness material joining type tool, wherein the support portion is made of a high-strength material, and further, the surface of the processed portion and at least a portion of the surface of the support portion that is continuous with the surface of the processed portion are coated with a hardened layer. (5) In the high-hardness material joining type tool described in claim 4, the above-mentioned high-hardness material is a cemented carbide, and the above-mentioned high-strength material is steel for tools. High hardness material joining type tool. (6) The high-hardness material bonded tool described in claim 4, characterized in that the high-hardness material is ceramics, and the high-strength material is steel for tools. A tool for joining high-hardness materials. (7) In a method for manufacturing a high-hardness material joining type tool in which a processing part made of a high-hardness material and a support part made of a high-strength material are integrally diffusion-bonded via a joining surface, the surface of the material of the processing part to be joined A diffusion material is interposed and fixed between the opposing surface of the support part material to be joined, and then all of this diffusion material is diffused through both surfaces under pressure to bond the processing part material and the support part together. A method for manufacturing a high-hardness material bonding tool that directly diffusion-bonds parts and materials at the bonding surface. (8) In the method for manufacturing a high-hardness material bonded tool described in claim 7, the high-hardness material is a cemented carbide, and the high-strength material is steel for tools. A method for manufacturing a high-hardness material joining type tool. (9) In the method for manufacturing a high-hardness material bonded tool as set forth in claim 7, the high-hardness material is ceramics, and the high-strength material is steel for tools. A method for manufacturing a high-hardness material joining type tool characterized by: (10) A method for manufacturing a tool bonded to a high hardness material as set forth in claim 7, wherein the pressurization is performed by high temperature isostatic pressure. Production method. (11) A method for manufacturing a high-hardness material joining type tool according to claim 7, wherein the high-temperature isostatic pressurization is capsule-type high-temperature isostatic pressurization. A method of manufacturing a material joining type tool. (12) In the method for manufacturing a high-hardness material bonding type tool as set forth in claim 7, the above-mentioned pressurization is performed by vacuum hot pressing. Method.