JPH0313282B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Industrial Application) The present invention relates to a metal wire for cutting or chamfering hard materials, and more particularly to a method for manufacturing a diamond powder wire that holds diamond powder in a uniform and firm arrangement on the surface layer. (Prior art) In recent years, metal wires (hereinafter referred to as wires) have been used for cutting ceramics, hard materials, semiconductor materials such as silicon and gallium arsenide, and for chamfering microscopic holes in metal workpieces. are being considered and implemented. The wire used for this purpose is a so-called saw wire, which is a high-tensile wire rod with extremely high strength. Since the grinding action is performed only by frictional force, there is a problem of poor processing efficiency. In addition, in the case of cutting, there is a method called discharge wire cutting, in which a high voltage is applied between the material to be cut and the wire, and the cutting is performed by electric discharge between the material and the wire.
This method has a problem in that the member to be cut is limited to only conductive materials. To this end, a new diamond wire has recently been developed whose surface is coated with diamond powder using the plating method, and studies have begun to consider methods for efficiently processing the wire using the grinding force of the diamond powder on the surface. In this method, diamond powder that is simply attached to the wire surface mainly by Cu plating or Ni plating has weak adhesion and it is difficult to form a uniform array over the entire circumference of the wire surface. Applying normal diamond grinding wheel manufacturing technology, when manufacturing diamond wire, we use Ni, Cu,
A method in which diamond powder is mixed with ordinary bond metal powder and the mixed material is sintered and fixed over the entire circumference of the wire surface is also conceivable. (Problem to be Solved by the Invention) However, it is certainly an ideal method to use the bond metal powder described above and sinter and fix the diamond powder mixed therein over the entire surface of the wire. However, at present,
First, it is almost impossible to manufacture such a long and thin wire using a normal sintering method.
Currently, double-structured wires such as copper or aluminum-coated steel wires are commonly used, but the (diamond + metal)-steel wire as the object of the present invention can be replaced with a simple double-structured steel wire. Even if the conventional double-structured wire manufacturing technology is applied as is to make the wire,
For example, in the wire drawing process, diamond powder severely attacks and wears out the wire drawing dies.
From a practical point of view, wire drawing using conventional techniques is impossible. In view of the above points, and by further finding an effective means for adhering diamond powder, the present invention provides diamond powder that is arranged and held more uniformly and more firmly in the surface layer than in the conventional fixing method. The object of the present invention is to provide a new method that allows wires to be manufactured easily. (Means for solving the problems) The means of the present invention for achieving the above object are as follows:
To explain using FIGS. 1 to 3, which correspond to embodiments, the present invention is a method for manufacturing a diamond wire. A mixed powder D of metal powder 4 and diamond powder 3 is filled into the gap S of the metal body A, and then both ends of the metal body A are sealed. FIG. 1 is a schematic diagram showing the structure of the metal body A,
A is a top view thereof, and b is a side view thereof. Next, the metal body A with both ends sealed is subjected to hot working selected from known hot extrusion or hot rolling, and then heat treatment and cold working are repeated to draw the wire to obtain the required wire diameter. Use it as a wire rod. FIG. 3b is a micrograph showing an example of the metal structure of the cross section. Furthermore, by removing the outer peripheral part 1 metal of the metal body A remaining as the outermost layer of the wire rod by polishing or pickling, diamonds are formed in the sintered metal layer 4' as shown in FIG. A diamond wire is obtained in which a mixed layer D' in which the powder 3 is uniformly held is exposed as the outermost layer of the wire. FIG. 3a is a micrograph showing an example of the metal structure of the surface of a diamond wire produced by the method of the present invention. (Function) The present invention allows the cylindrical metal body A as shown in FIG. 2, its material and dimensions can be formed to suit various usage conditions using the same or different metals with various components. In addition, the mixed powder D consisting of the metal powder 4 of various components and the diamond powder 3 homogeneously mixed in advance at a mixing ratio adapted to various usage conditions is filled and sealed in the gap S of the metal body A, so that it can be heated. Through cold working, the wire is manufactured while maintaining the mixing ratio and homogeneity during filling. Also, the entire outer circumference of the mixed powder D is covered with the outer circumference 1 of the metal body A.
Since the metal exists in a coated state, the wire drawing die during wire drawing comes into contact only with the outer peripheral part 1 metal and does not come into contact with the diamond powder 3. The wire rod having the required wire diameter thus obtained has an outer peripheral portion 1 whose outermost layer is thinned by drawing as described above.
Since it is only metal, when the metal is removed by ordinary polishing, pickling, etc., a mixed layer containing diamond powder 3, which is in the lower layer, is removed as shown in Figure 2.
D' appears on the outermost surface of the wire. (Example) More specific examples will be described below. FIG. 1 is a schematic diagram showing the structure of a cylindrical metal body A used in the present invention, in which a is a top view and b is a sectional view of the same side. Carbon steel is generally used as the material for the outer periphery 1 and the center 2 of the metal body A used here, but depending on the conditions of use, stainless steel, copper alloy, etc. may also be used. The metal material of the center portion 2 may be different from each other. Note that the thickness of the outer peripheral part 1, the diameter of the central part 2, the width of the gap S between the two, etc. are determined by the wire diameter of the final wire used, the average particle size of the diamond powder 3 to be filled, and the amount of powder into the metal powder 4. diamond powder 3
The suitability is determined according to the mixing ratio of The metal powder 4 with which the diamond powder 3 is mixed is generally Ni powder or Ni-based alloy powder, but other metals such as Cu powder or Cu-based alloy powder are also used, such as Cu powder or Cu-based alloy powder. It may be a powder. Then, after filling the mixed powder D, both ends of the gap S of the metal body A are sealed by welding the gap using an appropriate cover material, etc., and then subjected to normal hot extrusion or hot rolling, and then By repeatedly performing heat treatment and cold wire drawing, a wire rod having a desired wire diameter is obtained. At this time, if it is undesirable for the metal powder 4 filled inside to diffuse into the outer periphery 1 and the center 2 during hot working, copper plating or the like is applied to the inner surface of the outer periphery 1 and the outer periphery of the center 2 in advance. It is also possible to prepare a layer for preventing diffusion by applying a plating layer, and then use this plating layer to prevent the diffusion phenomenon. Below, further examples of manufacturing diamond wires by the method of the present invention will be presented. Example 1 The material of the cylindrical metal body A shown in FIG.
Made of SK7 steel. The dimensions of the cylindrical metal body A at this time are the outermost diameter of 70 mmφ and the thickness of the outer peripheral part 1 of 5.
mm, and the width of the gap S is 8 mm. Then, after filling the gap S with mixed powder D, which is a mixture of pure Ni powder and 0.5% by weight of carbon and 13% by volume of diamond particles 3 with an average particle size of 150 μm, both ends of the metal body A are filled. The gap S was sealed by welding. Thereafter, the mixture was heated at 1000°C for 2 hours and extruded at an extrusion ratio of 15. Furthermore, heat treatment and cold wire drawing were repeated to obtain a wire rod with a diameter of 1.0 mm. The tensile strength at this time is 182
It was Kg/ ^mm2 . FIG. 3b is an enlarged photograph showing an example of the cross section. This was immersed in a hydrochloric acid solution with a concentration of 35% for 15 minutes to dissolve and remove the carbon steel (SS41) of the outer peripheral part 1 of the metal body A remaining as the outermost layer of the wire, neutralized with an alkaline solution, and washed. FIG. 3a is a micrograph showing an example of the surface metallographic structure of the diamond wire manufactured in this manner. I can see that it has been done. Example 2 The material of the cylindrical metal body A shown in FIG.
SK7 was used. The dimensions of the cylindrical metal body A at this time are a maximum diameter of 70 mmφ, a thickness of the outer peripheral part 1 of 10 mm,
The width of the gap S is 4 mm. Then, there is a net in the gap S.
Diamond particles 3 with an average particle size of 15 μm are added to a mixture of Ni powder and 0.5% by weight of carbon at a volume ratio of 10%.
After filling the mixed powder D, the gap S at both ends of the metal body A was covered and hermetically sealed by welding. Thereafter, it was heated at 1000°C for 2 hours and extruded at an extrusion ratio of 15. Furthermore, heat treatment and cold wire drawing were repeated to obtain a wire rod with a diameter of 0.2 mm. The tensile strength at this time is 207
It was Kg/ ^mm2 . Add this to a 35% hydrochloric acid solution.
The carbon steel (SS41) of the outer peripheral part 1 of the metal body A remaining as the outermost layer of the wire was dissolved and removed by immersion for 20 minutes.
It was neutralized and washed with an alkaline solution. The diamond wire manufactured in this way has a stronger adhesion force to the wire surface of the diamond particles 3, as is clear from the results in Table 1 below, compared to the diamond wire of the same wire diameter made by the conventional plating method, and In addition to being able to increase speed, it also had a significantly longer lifespan.

[Table] (Effects of the Invention) As explained above, the present invention allows the required components and mixing ratio to be mixed into the gap between the outer periphery and the center of the cylindrical metal body, which can be easily formed according to the required dimensions. It is filled and sealed with a mixed powder of metal powder and diamond powder, and the outer periphery is only metal, so even if the conventional double structure wire manufacturing technology is applied and processed, the diamond powder will not flow into the wire drawing die. There is no concern that the wire will be directly attacked, and it is now possible to easily draw the wire to the required wire diameter in the same way as conventional double-walled steel wire. Also, in the final step of exposing the mixed layer containing diamond powder as the outermost layer of the wire, metal remaining on the surface of the wire can be easily removed by applying polishing or pickling treatment. . Moreover, the metal body whose gap is filled with mixed powder and sealed is directly subjected to known hot extrusion or hot rolling,
Furthermore, heat treatment and cold wire drawing are repeated to obtain a wire rod of the required diameter, so the metal layer formed by sintering the metal powder in the mixed powder contains diamond powder at the same mixing ratio as when filling. The wire can be placed and held evenly and firmly, allowing for faster cutting speeds and a longer wire life than the conventional plating method in which diamond powder is only attached to the wire surface. , it is possible to easily produce extremely excellent diamond wire for cutting or chamfering. Furthermore, the gripping force of the diamond powder against bending is significantly greater than that obtained by the Metsuki method.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the structure of a cylindrical metal body used in the present invention, in which a is a top view and b is a sectional view of the same side. Figure 2 shows a conceptual diagram of a diamond wire manufactured by the method of the present invention, and Figure 3a shows an example of the metal structure on the surface of the wire using a microscope (magnification: 80
FIG. 3b is a microscopic (80x magnification) photograph showing an example of the metal structure of a cross section of a wire rod (before polishing and pickling treatment) in the middle of production by the method of the present invention. A... Cylindrical metal body, S... Gap in the metal body,
D...Mixed powder, D'...Mixed layer, 1...Outer periphery of metal body, 2...Center of metal body, 3...Diamond powder, 4...Metal powder, 4'...Metal layer .

Claims (1)

[Scope of Claims] 1 A mixed powder of metal powder and diamond powder is filled into the gap of a cylindrical metal body of a required size with a gap provided between the outer periphery and the center, and then the powder filling is performed. After sealing both ends of the metal body, it is subjected to hot extrusion or hot rolling, and then subjected to repeated heat treatment and cold working to form a wire rod, and the outer peripheral metal remaining as the outermost layer of the wire rod is mechanically processed. A method for manufacturing a diamond wire, which comprises removing the metal powder and diamond powder by a chemical method to expose a mixed layer of the metal powder and diamond powder on the surface of the wire. 2. The method of manufacturing a diamond wire according to claim 1, wherein the outer circumference and center of the cylindrical metal body are made of the same or different metal components. 3. The method for manufacturing a diamond wire according to claims 1 and 2, which has a core wire made of a high carbon steel wire whose tensile strength has been increased by cold working.