JPH0369860B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for joining a diamond-based sintered material member to a tungsten carbide-based cemented carbide member (hereinafter simply referred to as a cemented carbide member) with high bonding strength. [Prior Art] In general, diamond-based sintered materials are produced by blending at least one of Co powder and Ni powder, or both, as a binder phase forming component, with the remaining main portion being diamond powder. It is manufactured by heating and sintering at a high temperature of approximately 1400℃ under ultra-high pressure above atmospheric pressure, and because it has high hardness and excellent wear resistance, it is mainly used for nonmetals and nonferrous metals. It is used as a cutting tool for cutting etc. In this case, the above-mentioned diamond-based sintered material member usually contains Co and Co as binder phase forming components.
It is put into practical use in a state where it is joined to a cemented carbide member containing one or both of Ni and the remaining main part is tungsten carbide (hereinafter referred to as WC). Since it is extremely difficult to join by normal means such as brazing, the cemented carbide member is inserted together with the diamond-based sintered material when the diamond-based sintered material is sintered. Currently, bonding is performed at the same time. [Problems to be Solved by the Invention] As described above, since the joining of the diamond-based sintered material member and the cemented carbide member is performed simultaneously with the sintering of the diamond-based sintered material, the cemented carbide The production ratio of diamond-based sintered material decreases as the number of parts occupies, and this becomes a cause of high costs. Therefore, a diamond-based sintered material member can be processed into a cemented carbide member without using ultra-high pressure as is used in the production of diamond-based sintered material, and separately from sintering of the diamond-based sintered material. If it can be joined to the diamond-based sintered material, the production rate of diamond-based sintered material will increase by the amount of the cemented carbide component that was conventionally inserted together, and it will be possible to reduce costs by that amount. Furthermore, as mentioned above, it is difficult to join a diamond-based sintered material member to a cemented carbide member using normal joining means. It is difficult to manufacture a cutting tool with a joined structure, but if these two members can be joined without using ultra-high pressure, manufacturing the cutting tool will be extremely easy. [Means for solving the problem] Therefore, from the above-mentioned viewpoint, the present inventors conducted research to bond the above-mentioned diamond-based sintered material member to a cemented carbide member without using ultra-high pressure. As a result, the bonding surface of both members contained at least 3 to 20 atom % of B (boron), and further contained 1 to 10 atom % of C (carbon) as necessary, and the remaining Both parts were weighed at 30 kg/100 lbs. with a brazing filler metal having a composition or component composition mainly consisting of Co and/or Ni.
When heated to a temperature of 750 to 900°C while applying a pressure of 30 to 300 kg/cm ² or ^more , the B component or B and C components in the brazing filler metal are As it diffuses into the binder phase, the binder phase of the two components and the brazing filler metal become integrated, and as a result, the two components have an extremely high bonding strength, that is, a high shear strength of 20 kg/mm ² or more. They found that they can be bonded together. This invention was made based on the above knowledge, and it is based on the above findings that Co and Ni are used as bonding phase forming components.
A diamond-based sintered material member containing one or both of the following is also used as a binder phase forming component.
When bonding to a cemented carbide member containing either or both of Co and Ni, the bonding surfaces of these two members contain at least 3 to 20 atomic percent of B, and if necessary, 1 to 20 atomic percent of C. 30 Kg/cm ² or more, with a brazing filler metal containing 10 atomic % and the remaining main part consisting of Co and/or Ni, Practically speaking, the B component in the brazing filler metal and, if necessary, the C component are heated to a predetermined temperature within the range of 750 to 900°C while applying a pressure of 30 to 300 Kg/cm ² . The feature is that the two members are firmly bonded by diffusing into the members. Next, the reason for limiting the conditions as described above in the joining method of the present invention will be explained. (a) B content in the brazing filler metal The B component lowers the melting point of the brazing filler metal, forms a liquid phase at a temperature of 750 to 900°C, which is the bonding heating temperature, and is itself in a pressurized state. It also diffuses into Co and/or Ni, which are the main constituents of the binder phase of bonding components, and has the effect of integrating these components and ensuring a strong bond, but if the content is less than 3 at%, The desired effect is not obtained from the action,
On the other hand, if the content exceeds 20 atom%, a considerable amount of the B component will remain on the joint surfaces of both parts, and this B component will form a brittle compound with the binder phase forming components and brazing material components of the joint parts. If a large amount of this compound is formed, the bonding strength of the bonded surface will be significantly reduced, so its content was determined to be 3 to 20 atomic percent. (b) C content in the brazing filler metal The C content is relatively low as it coexists with the B component and has the effect of further lowering the melting point of the brazing filler metal and causing the brazing filler metal to become liquid at low temperatures. It is blended or included as necessary when a bonding heating temperature is required, but if the content is less than 1 atomic %, the desired effect cannot be obtained, whereas if it is contained in excess of 10 atomic %, The content was determined to be 1 to 10 atomic % because free carbon remains on the bonding surface and reduces the bonding strength. (c) Bonding heating temperature At a bonding heating temperature of less than 750°C, the diffusion rate of the B component into the bonding members is low, and as a result, a large amount of the B component remains on the bonding surface, making it difficult to obtain high bonding strength. On the other hand, if the welding heating temperature exceeds 900°C, deterioration occurs especially in the diamond-based sintered material parts, and although high joint strength can be obtained, cutting performance deteriorates.
The temperature was set at 750-900℃. (d) Additional pressure During joining, pressure is applied to the joining surfaces of the joining members to prevent the formation of voids that will cause a reduction in joint strength, but the added pressure is 30Kg/cm ²
Since it is not possible to completely prevent the generation of voids if the pressure is less than 30 kg/cm ² , it is necessary to apply a pressure of 30 Kg/cm 2 or more to obtain a uniform joint surface without voids. Note that the higher the applied pressure, the higher the bonding strength;
Practically, sufficient bonding strength can be obtained with an additional pressure of 30 to 300 kg/cm ² . In carrying out the joining method of the present invention, it is preferable that the brazing filler metal is applied to the joint surfaces that have been ground smooth by a plating method or a powder coating method. The joining is
It is preferable to use a hot press machine capable of controlling the atmosphere in a non-oxidizing gas atmosphere or in a vacuum, and the atmosphere may be air if it can be carried out in a closed container. [Example] Next, the joining method of the present invention will be specifically explained with reference to Examples. Example 1 As a joining member, a diamond-based sintered material member having dimensions of diameter: 7 mmφ x thickness: 1 mm and having the composition shown in Table 1, and a diamond-based sintered material member with a diameter of 7 mm.
A cemented carbide member having dimensions of φ×thickness: 6 mm and having the same composition as shown in Table 1 was prepared. On the other hand, as a brazing filler metal forming powder, average particle size: 1.2μ
A Co powder having a diameter of 1.8 μm, a Co-B alloy (containing 30 at% B) powder having a diameter of 1.8 μm, and a carbon powder having a diameter of 0.5 μm were prepared, and these powders were blended into the composition shown in Table 1. Add an organic adhesive to this and mix to form a paste, and apply this paste to each bonding surface of the above bonding member in a layer of 5 μm.
After applying the coating to an average thickness of

【table】

[Table] Invention joining methods 1 to 11 and comparative joining methods 1 to 4 were performed by inserting the mold into a mold having an inner diameter of 7 mmφ and performing joining under the same conditions shown in Table 1. carried out. Note that Comparative Bonding Methods 1 to 4 were all carried out under conditions in which the composition of the brazing filler metal and the bonding conditions (marked with *) were outside the scope of the present invention. be. Next, the shear strength of the bonded surfaces of the resulting bonded members was measured, and the condition of the bonded surfaces was observed. The results of these measurements and observations are shown in Table 1. Example 2 As a joining member, diameter: 6 mmφ x thickness: 1.2 mm
A diamond-based sintered material member having the dimensions and the composition shown in Table 2, and a diameter: 6
A cemented carbide member having dimensions of mmφ×thickness: 4 mm and having the same composition shown in Table 2 was prepared. On the other hand, as a brazing filler metal forming powder, average particle size: 1.5μ
Ni-B alloy (containing 20 at% B) powder with m, Co-B alloy (containing 30 at% B) with the same 1.8 μm
powder, 1.2 μm Co powder, 1.5 μm Ni powder,
and 0.5 μm carbon powder, these powders were blended into the composition shown in Table 2, an organic adhesive was added and mixed to form a paste, and these pastes were mixed with the diamond-based sintered Apply it to the joint surface of the material parts at an average thickness of 8 μm, and then
The diamond-based sintered member thus prepared was stacked on the cemented carbide member with their joint surfaces in contact with each other, and then placed in a cavity with an inner diameter of 6 mmφ in a hot press machine that pressurized it with upper and lower graphite punches. The bonding methods 12 to 22 of the present invention can be obtained by inserting and bonding under the conditions shown in Table 2.
and comparative joining methods 5 to 8 were carried out, respectively. In addition, comparative joining methods 5 to 8 are all based on Example 1.
As in , some of the conditions were outside the scope of the present invention. Regarding these, as in Example 1,

[Table] The shear strength of the bonded surfaces was measured and the condition of the bonded surfaces was observed, and the results are shown in Table 2. In addition, for the bonding methods 12, 13, and 14 of the present invention, B and
When the maximum diffusion depth of Ni was measured using an XMA (X-ray microanalyzer), the third
The results are shown in the table.

〔Effect of the invention〕

As is clear from the results shown in Tables 1 to 3, according to the joining method of the present invention, the constituent components of the brazing filler metal are sufficiently diffused into the joining members, and there is no formation of voids on the joining surfaces, resulting in good results. In the bonded state, and 20
While diamond-based sintered material parts can be firmly joined to cemented carbide parts with high shear strength of Kg/ ^mm2 or more, as seen in comparative joining methods 1 to 8, the composition of the brazing filler metal If any of the composition and bonding conditions are outside the scope of this invention, the bonding condition will be poor and the shear strength of the bonded surface will be 20%.
It can be seen that the bonding strength is as low as Kg/mm ² or less, making it impossible to bond with high bonding strength. As mentioned above, according to the joining method of the present invention,
Diamond-based sintered material parts to cemented carbide parts,
Since it is possible to bond firmly without using ultra-high pressure, it brings about industrially useful effects such as reducing the manufacturing cost of diamond-based sintered materials and significantly expanding the field of use thereof.

Claims (1)

[Claims] 1. A diamond-based sintered material member containing either or both of Co and Ni as a bonding phase forming component, which also contains either or both of Co and Ni as a bonding phase forming component. When joining to tungsten carbide-based cemented carbide members,
At least B: 3 to 20 on the joint surfaces of these two members.
At a pressure of 30 Kg/cm 2 or more, these two members are interposed with a brazing filler metal having a composition or component composition in which Co and/or Ni are included and the remaining main portion is Co and/ ^or Ni. While adding
A method for joining a diamond-based sintered material member to a tungsten carbide-based cemented carbide member, characterized in that the B component in the brazing filler metal is diffused into both members. 2 A diamond-based sintered material member containing either or both of Co and Ni as a binder phase-forming component, and a tungsten carbide-based cemented carbide member that also contains either or both of Co and Ni as a binder phase-forming component. When joining parts,
At least B: 3 to 20 on the joint surfaces of these two members.
Atomic % and C: 1 to 10 at. , heating to a predetermined temperature within the range of 750 to 900°C while applying a pressure of 30 kg/cm ² or more to diffuse the B and C components in the brazing filler metal into both members. A method of joining a diamond-based sintered material component to a tungsten carbide-based cemented carbide component.