JPS62297404A - Production of wire incrusted with cubic boron nitride - Google Patents

Abstract

PURPOSE:To prevent the generation of chipping on the surface in the central part of a cylindrical metallic body and to extend the life of a wire by mounting a metallic pipe or thin film to the central part in a production process for packing and hermetically sealing a mixture composed of metallic powder and CBN particles into the space between the outermost peripheral part and central part of said body and subjecting the body to hot working, etc. CONSTITUTION:A pipe-shaped metallic body B is inserted into the space S of the cylindrical metallic body A of a required size provided with the space S between the outermost peripheral part 1 and the central part 2 in such a manner that said body is held in tight contact with the central part 2 so as to make the space with the outermost peripheral part 1. A thin metallic strip may be otherwise wound in the central part 2. The powder mixture D composed of the metallic powder 4 and the CBN (cubic boron nitride) particles 3 is packed into the space S' between the metallic body B and the outermost peripheral part 1 and both ends of the metallic body A are hermetically closed. Such metallic body A is subjected to hot working such as extruding or rolling and to a heat treatment such as annealing or patenting and is further drawn by cold working to the wire of a desired wire diameter.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention <Industrial Application Field> This invention is characterized by the fact that cubic nitride elementary particles [hereinafter referred to as CB N (Cubic Boron N1t)
The present invention relates to a method for manufacturing a CBN incrust wire characterized in that the wires (abbreviated as "ride") are in close contact with each other.

<Prior art> In recent years, the use of wires for cutting ceramic and cemented carbide materials, cutting semiconductor materials such as silicon and gallium arsenide, and even chamfering metal workpieces with very narrow holes has been considered or used. It has been implemented.

<Problems to be solved by the invention> For this reason, extremely strong high tensile strength wires, so-called saw wires, have been used as wires, but
In this case, since the cutting is performed only by friction between the wire and the material to be cut, there is a problem of poor cutting efficiency.

There is also a method called discharge wire cutting, in which a high voltage is applied between the material to be cut and the wire, and the wire is cut by electrical discharge between them. There is a problem that the material of the material is limited.

On the other hand, in recent years, a cutting method using a diamond wire whose surface is coated with fine diamond particles by plating has become known.

However, this method only coats the wire surface with diamond particles mainly by false plating or N plating, so the diamond adhesion is weak and it is difficult to uniformly coat the entire wire surface. There was a problem of difficulty.

Furthermore, when cutting and grinding using diamond, if the workpiece is a ferrous material,
There is a problem that adhesion between diamond and iron tends to occur, making it difficult to process.

In addition, a cylindrical metal body with a gap between the outermost periphery and the center is used, and this gap is filled with a mixture of metal powder and CBN particles, sealed, and subjected to hot processing such as extrusion or rolling. There is a method of manufacturing similar wire rods by performing heat treatment such as annealing and patenting, and then cold working.
With this method alone, if the dimensions of the gap are set so that the CBN particles are sufficiently exposed on the surface of the final wire after the outermost metal is removed, the CBN particles may end up digging into (protruding from) the center. ), there is a problem that a notch is created in the center.

In this way, if a notch occurs on the surface of the central portion that actually supports the strength of the wire, the wire becomes extremely susceptible to breakage, resulting in a shortened lifespan as a wire.

Means for Solving the Problems> In view of the above points, the present invention eliminates the occurrence of notches in the center while maintaining conditions that allow CBN particles to be exposed, thereby extending the life of the wire. The purpose of the present invention is to provide a novel method for manufacturing CBN incrust wire.

That is, the present invention provides a metal body having a required size, which is formed by inserting a cylindrical metal body having an outer diameter smaller than the inner diameter of the metal body into the center of the cylindrical metal body, and a cylindrical metal body having a diameter smaller than the inner diameter of the cylindrical metal body. Either insert a pipe-shaped metal body in close contact with the central cylindrical metal body to create a gap, or wrap a metal thin film around the central cylindrical metal body to create a gap between the cylindrical metal body and the cylindrical metal body. A mixed powder of metal powder and cubic boron nitride particles is filled into the gap, then both ends of the powder-filled metal body are sealed, and then hot processing such as extrusion or rolling or heat treatment such as annealing or patenting is performed. The metal powder is baked on the surface of the wire by further cold working to form a wire, and the cylindrical metal part of the metal body remaining as the outermost layer of the wire is removed by mechanical or chemical methods. The present invention is a method for manufacturing a cubic boron nitride incrust wire, which is characterized by exposing a mixed layer of solidified metal and cubic boron nitride particles.

<Operation> The method of the present invention will be explained with reference to FIGS. 1 to 3 corresponding to the embodiments. In the method of manufacturing CBN incrust wire, first, the outermost peripheral part 1 and the central part 2 are separated. A cylindrical metal body A having the required dimensions with a gap S provided therebetween, and a pipe-shaped metal body B in close contact with the center part 2 so that a gap is created between the outermost peripheral part 1 and the gap S. The metal powder 4 and the CBN particles 3 are inserted into the gap S' between the thin metal ribbon C and the outermost peripheral part 1.
After filling the mixed powder with the above metal body A, both ends of the metal body A are sealed.

Figures 1 and 2 are schematic diagrams showing 11 structures of the metal body A. Figure 1 shows the case where the pipe-shaped metal body B is used, and Figure 2 shows the case where the metal ribbon C is used. , (a) is a top view thereof, and (b) is a sectional view of the same side.

Next, the metal body A with its both ends sealed is subjected to known hot working such as extrusion or rolling, or heat treatment such as annealing or patenting, and then drawn by cold working to obtain a wire rod of the desired wire diameter. .

Figure 3 shows an example of the cross-section of metal 1a during wire drawing.
This is a 20x micrograph.

Further, the CBN particles are uniformly held in the sintered metal layer by removing the outermost metal of the metal body A remaining as the outermost layer of the wire by polishing or pickling. This results in a CBN incrust wire in which the mixed layer is exposed as the outermost layer of the wire.

The material of the outermost peripheral part 1 and the center part 2 shown in FIG. Although gold alloy is used, stainless steel, t-alloy, etc. may also be used depending on the conditions of use. Furthermore, these materials may be different from each other. Note that these dimensions can be arbitrarily selected depending on the diameter of the final wire used, the particle size of the CBN to be filled, and the filling ratio.

Further, as the metal powder to be mixed with the CBN particles, NL powder, N, and foundation gold powder are generally used, but in addition to these, metal powder, Q-based metal powder, Fe powder, and Fe-based gold powder may also be used.

After sealing both ends of the powder-filled metal body A,
The wire rod is subjected to hot working such as extrusion or rolling, or heat treatment such as annealing or patenting, and then cold working to obtain a wire rod with a desired wire diameter.

After that, in the drawn steel wire, the outermost metal of the metal body remaining as the outermost layer is removed mechanically, chemically, etc., and the metal powder and CBN particles are sintered on the wire surface. This allows CBN to adhere more firmly than wires produced by conventional plating methods, and does not use conventional pipe-shaped metal bodies or thin metal strips.
Compared to a wire manufactured by a wire drawing method, it is possible to obtain a CBN incrust wire in which the CBN particles dig into the center, and there is no possibility that a notch will be formed in the center and the life of the wire will be shortened.

<Example> Hereinafter, this invention will be explained in detail with reference to Examples.

Example 1 The material of the cylindrical metal body A shown in FIG.
General structural rolled steel material (JlS-8841) was used for the center part 2, and carbon tool steel material (JlS-8K7) was used for the center part 2. The dimensions of the cylindrical metal body A at this time are the outermost diameter 7
0 darkness φ, thickness of outermost periphery 1 5 width of BN @ S 6 rr
It is rtn. Then, an iNL tube B with an inner diameter of 48 mm and a thickness of 2 rxrr is inserted into the gap S, and this Nu
After filling the gap S' between the tube and the outermost peripheral part 1 with a mixed powder mixture of pure N, powder 4, and CBN particles 3 with an average particle size of 140 μm at a volume ratio of 13%, the gap S' at both ends of the metal body A is filled.
The parts were welded and sealed.

Thereafter, the mixture was heated at 1050° C. for 2 hours and extruded at an extrusion ratio of 15. Furthermore, heat treatment and cold wire drawing are repeated, 1. The wire rod was made of OMφ. The tensile strength at this time is 13
8/(g-d. FIG. 3 is a micrograph showing an example of the structure of a cross section during wire drawing in this example.

As is clear from this, it was found that the CBN particles were separated from the center by the pipe-like Nu, and the CBN particles did not bite into the center and form a notch.

This is immersed in a salt M solution with a concentration of 35% for 15 minutes, and 1 g of charcoal remains at the outermost peripheral part 1 of the metal body A as the outermost layer of the wire.
flA (8841) was dissolved and removed, neutralized with an alkaline solution, and washed.

The CBN incrust wire manufactured by this method is
CBN particles 3 are uniformly attached to the outer periphery, and
It was confirmed that the CBN particles did not dig into the center of the wire, and the wire had a long life without notches.

Furthermore, in cutting and grinding of iron-based materials,
In contrast to conventional diamond wires, which were difficult to process due to adhesion, we were able to perform extremely good cutting and grinding processes.

Example 2 As the material of the cylindrical metal body A shown in FIG. 1, the outermost periphery 1 is made of general structural carbon! III tube (JIS 5TK30
), and piano wire (JISSWR872
B> was used. The dimensions of the cylindrical metal body A at this time are: maximum diameter 20r111, outermost circumference 1 thickness 2#, center portion 2
The diameter is 13mm. Then, this central portion 2 has a thickness of 0.
A 1H 1iH4jL ribbon was tightly wound to a thickness of 0.5a, and pure NL powder and CBN particles 3 with an average particle size of 15μ were mixed in a volume ratio of 13% in the gap S' between this and the outermost peripheral part 1. After filling the mixed powder, the gaps S at both ends of the metal body A were covered and hermetically sealed by welding.

Thereafter, the wire rods were heated to 850° C., and then subjected to a heat treatment of cooling in the air and cold wire drawing seven times to obtain wire rods with a diameter of 0.2. The tensile strength at this time was 171 KW4.

This was immersed in a hydrochloric acid solution with a concentration of 35% for 20 minutes, and the carbon m (
STK30) was dissolved and removed, neutralized with an alkali solution, and washed.

The CBN incrust wire manufactured in this manner has a higher value as shown in Table 1 below, compared to a CBN incrust wire of the same wire diameter manufactured by the wire drawing method without using a conventional pipe-shaped metal body or metal ribbon. As is clear from the results, CBN
The particle 3 bites into the center part 2, and there is a notch in the center part.
It had an extremely long lifespan and was not susceptible to breakage.

Table 1 <Effects of the Invention> As detailed above, the CBN incrust wire made by the method of this invention has a significantly longer lifespan than the wire made by the conventional wire drawing method, and can be used as an extremely excellent cutting wire. It can be widely used and can even be used as a wire for chamfering.

[Brief explanation of the drawing]

1 and 2 are schematic diagrams showing the structure of a cylindrical metal body used in the present invention, in which FIG. 1 shows the case where the metal body is a pipe-shaped metal body, and FIG. 2, (b) is a side sectional view, FIG. 2 is a case where the metal body is a gold thin strip, the same figure <8) is a top view, (b) is a side sectional view, and FIG. 3 is this. 1 is a photomicrograph magnified approximately 120 times, showing an example of the metallographic structure of a cross section of a wire during production by the method of the invention. A...Cylindrical metal body B...Pipe-shaped metal body C...Gold II ribbon D...Mixed powder 1...Outermost peripheral part of metal body 2...Central part 3 of metal body ...CBN particles 4...Metal powder S
...Gap S' between the outermost periphery of the metal body and the center...Gap between the outermost periphery of the metal body and the pipe-shaped metal body or metal ribbon Figure 1 Figure 2 (Q>, (a) Figure 1 Figure 2 (b) (b) Figure 8 m--7", g-""'y-7 ni"~'

Claims (2)

[Claims] (1) In a metal body having the required dimensions, which is formed by inserting a cylindrical metal body having an outer diameter smaller than the inner diameter of the metal body into the center of the cylindrical metal body, there is a gap between the cylindrical metal body and the cylindrical metal body. Either insert a pipe-shaped metal body in close contact with the central cylindrical metal body, or wrap a metal thin film around the central cylindrical metal body and insert it into the gap between this and the cylindrical metal body. Filled with a mixed powder of metal powder and cubic boron nitride particles,
Next, after sealing both ends of the powder-filled metal body, it is subjected to hot working such as extrusion or rolling, or heat treatment such as annealing or patenting, and further cold working to form a wire rod, and as the outermost layer of the wire rod. The remaining cylindrical metal body portion of the metal body is removed by a mechanical or chemical method to expose a mixed layer of the metal sintered with the metal powder and cubic boron nitride particles on the wire surface. A method for producing a characteristic cubic boron nitride incrust wire. (2) The cubic boron nitride incrust according to claim 1, wherein the cylindrical metal body, the pipe-shaped metal body to be inserted, or the metal ribbon to be wrapped are made of the same or different metal components. Method of manufacturing wire.