JPH03215669A - Artificial diamond coated throw away tip and its production - Google Patents

Abstract

PURPOSE:To produce a long-life artificial diamond coated throw away tip by coating a part, other than the machining working part, or the whole of a throw away tip base material with a Ta sheet and then coating the surface with artificial diamond. CONSTITUTION:A part, other than the machining working part, or the whole of the surface of a throw away tip base material composed of sintered hard alloy base material is coated with a Ta sheet, such as metallic foil. Subsequently, this surface is coated with artificial diamond by an artificial vapor phase synthesis method, etc. By this treatment, an artificial diamond coating layer is formed at least on the machining working part of the above base material, and also a part free from the artificial diamond coating layer is provided to the part other than the above machining working part. By this method, the internal stress of the artificial coating layer is reduced and the occurrence of cracks and peeling can be prevented, by which the long-life artificial diamond coated throw away tip can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an indexable tip having a diamond coating layer with excellent peeling resistance and a method for manufacturing the same.

[Conventional technology]

In general, there are two types of indexable inserts: indexable positive inserts whose upper and lower surfaces have different sizes, and indexable negative inserts whose upper and lower surfaces are the same in size. It is also known that there are indexable positive tips and indexable negative tips that have mounting holes so that they can be used and attached to a cutting tool or the like.

Conventionally, to cut non-ferrous metals such as Al, Ap alloys, Cu, Cu alloys, and graphite, natural diamond tips or indexable tips with diamonds manufactured by high-temperature and high-pressure synthesis embedded in the cutting edge have been used. There is.

However, these chips are expensive because it is difficult to process these natural diamond chips or the diamond embedded in the cutting edge of the chip into a predetermined shape. Therefore, in recent years, an inexpensive diamond-coated indexable tip has been proposed in which the surface of a base material such as cemented carbide or ceramic is coated with artificial diamond using an artificial vapor phase synthesis method. The artificial vapor phase synthesis method described above includes a method using a thermionic emitting material described in JP-A-58-91100, and JP-A-58-1351.
A method using plasma discharge using high frequency waves as described in Japanese Patent Application No. 17, a method using plasma discharge using microwaves as described in Japanese Unexamined Patent Publication No. 11049/1984, and the like are known.

[Problem to be solved by the invention]

However, in these artificial diamond-coated indexable tips, internal stress remains in the artificial diamond coating layer due to the difference in thermal expansion coefficient between the base material and the artificial diamond coating layer. There was a problem in that the artificial diamond coating layer peeled off during cutting.

In order to solve this problem, a method has been proposed in which boron, etc., which has an atomic radius smaller than that of carbon, which is the main component of diamond, is injected when forming the artificial diamond coating layer to form an artificial diamond coating layer with less internal stress. However, this boron injection method is extremely difficult to control, which makes it difficult to put it into practical use.

[Means to solve the problem]

Therefore, the present inventors conducted research to solve these problems and found that the conventional artificial diamond-coated indexable tip is
Because the entire indexable chip base material is coated with artificial diamond, a region with a different coefficient of thermal expansion from that of the indexable chip base material spreads throughout the base material, and as a result, a large amount of internal stress remains in the thin artificial diamond coating layer. In order to reduce the internal stress of the artificial diamond coating layer on Hamurakami, the area of the artificial diamond coating layer is made as small as possible, and it is formed only on the cutting action part,
They discovered that by leaving as much of the non-formed part of the artificial diamond coating layer as possible, it is possible to form an artificial diamond coating layer with less internal stress on the surface of the base material.

This invention has been made based on this knowledge, and is characterized by forming an artificial diamond coating layer on at least the cutting action portion of the indexable tip base material, leaving a portion where the artificial diamond coating layer is not formed. This invention is characterized by an artificial diamond-coated indexable tip and its manufacturing method.

Next, the artificial diamond-coated indexable tip of the present invention and its manufacturing method will be explained in detail with reference to the drawings.

FIG. 1 is a perspective view of an artificial diamond-coated indexable positive chip of the present invention in which an artificial diamond coating layer is formed on the entire upper surface and part of the side surfaces. As shown in the figure, the indexable chip base material 2 is placed on the pits 3 of the graphite substrate 4 having a plurality of pits 3, and the indexable chip base material 2 is placed in an artificial diamond precipitation production apparatus using a normal artificial vapor phase synthesis method. When an artificial diamond coating layer is formed on the surface of the indexable chip base material 2, the artificial diamond coating layer 1 is formed on the parts protruding from the pits 3, and no artificial diamond coating layer is formed on the parts buried in the pits 3. It remains as a non-formed portion 5. The diamond-coated indexable indexable insert shown in FIG. 1 produced in this way has a low internal stress in the artificial diamond coating layer, so the artificial diamond coating layer does not crack or peel during cutting. Since no artificial diamond coating layer is formed on the lower surface, the chip sits comfortably and has excellent effects such as less wear on the base metal.

Furthermore, as shown in FIGS. 2 to 5, the artificial diamond-coated indexable positive tip of the present invention has the following features:
A non-forming portion 5 can be provided on a part of the upper surface of the artificial diamond-coated indexable positive tip. 2nd above
The artificial diamond-coated indexable insert shown in Figures 5 to 5 has the following features: (a) Since the internal stress of the artificial diamond coating layer is small, cracks or peeling of the artificial diamond coating layer are less likely to occur during cutting. , (b) Since there is no artificial diamond coating layer on the bottom surface, the chip sits well and there is less wear on the alloy. (c) Because the non-formed part 5 exists in the center of the top surface, the bottle, It has excellent effects such as less wear on screws, pawls, and other holders.

In order to manufacture the artificial diamond-coated indexable positive tips shown in FIGS. 2-5 above, the steps shown in FIGS.
- Metal foil 7 or metal tape 8 as shown in Figure 1.
is pasted and placed in that state on the bit 3 of the graphite substrate 4 shown in FIG. It can be manufactured by removing the foil 7 or the metal tape. FIG. 6 shows a synthetic diamond coated indexable positive tip with a mounting hole 6.

The metal foil 7 or the metal tape 8 may be a foil or tape of W, Mo, stainless steel, etc., or it is particularly possible to cover the indexable positive chip base material 2 using Ta metal foil or Ta metal tape. Most preferred. T
If a metal foil or metal tape other than a metal foil or Ta metal tape is used, if there is a gap between the metal foils or metal tapes, a sufficient non-forming part 5 cannot be obtained. This is because by pasting the Ta metal tape, the non-forming portion 5 can be created without any problem even if there is the above-mentioned gap.

Although the artificial diamond-coated indexable positive tip of the present invention has been described above, the present invention is not limited to the above-mentioned positive tip, but as shown in FIGS. 7 and 8, the artificial diamond-coated indexable indexable tip It also includes chips.

Furthermore, instead of pasting the Ta foil or Ta tape, a Ta plating layer or a Ta vapor deposition film may be formed, leaving the cutting action portion of the indexable chip base material and not forming an artificial diamond coating layer.

〔Example〕

This invention will be specifically explained based on examples.

WC powder, Tic powder, and Co powder, all of which have a predetermined average particle size, are prepared as raw material powders, and these raw material powders are blended so that Co: 6% by weight, TaC: 1% by weight, and the remainder WC is 1%. The powder was wet mixed in a ball mill for 3 hours, dried, and then press-molded into a green compact at a pressure of 1.51 on/cd. A WC-based cemented carbide substrate is produced by sintering under the conditions of time holding, and the surface of this substrate is ground, and its shape conforms to ISO standard S-P G N 1.
A throw-away positive chip base material of 20308 or S P MWl of 2030 g was prepared.

Example 1 This indexable positive chip base material was charged into a pit of a graphite substrate as shown in FIG.
It was charged into a quartz reaction vessel equipped with a metal filament without being coated with any metal foil or Ta metal tape, atmospheric pressure: 30 Torr, chip base material temperature = 850°C, reaction gas composition: volume ratio te CH4/H2 =l/lO01
The artificial diamond-coated indexable positive tip shown in FIG. 1 was produced by processing under the following conditions for a reaction time of 5 hours.

Using this artificial diamond-coated indexable positive tip, workpiece material: AN-12%S1, cutting speed: 1000m/IIlin, depth of cut: 1. O
mm, feed: 0. lmm/rev. A milling cutting test was conducted under the conditions of , and each pass was 1 minute, and the cutting edge and workpiece were observed after each pass. The number of times was measured, and the results are shown in Table 1.

Example 2 The above indexable chip base material was covered with a Ta metal tape in a cross shape as shown in FIG. 2-1, and this was inserted into the pit of a graphite substrate as shown in FIG. The artificial diamond-coated indexable positive tip shown in FIG. 2 was prepared by charging it into a quartz reaction vessel equipped with a metal filament and treating it under the same conditions as in Example 1 in exactly the same manner as in Example 1, and carried out the experiment. A milling test was conducted under the same conditions as those shown in Example 1, and the number of passes until peeling occurred in the artificial diamond coating layer of the artificial diamond-coated indexable positive tip was measured. The results are shown in Table 1. Ta.

Examples 3 to 5 The Ta metal foil was attached in the same manner as in Example 2 except that the Ta metal foil was attached to the center of the upper surface of the indexable positive chip base material as shown in FIGS. 3-1 to 51. Figure 3~
The artificial diamond-coated indexable inserts shown in FIG. 5 were prepared, and milling tests were conducted in the same manner as in Example 1. The number of passes until peeling occurred was measured. The results are shown in Table 1. Ta.

Comparative Example 1 Furthermore, for comparison, an artificial diamond coating layer was formed on the entire surface of the base material of the above indexable positive tip, a conventional artificial diamond coated indexable positive tip was prepared, and a milling cutting test was conducted. The number of passes up to i11ll was determined and the results are shown in Table 1.

Table 1 [Effects of the Invention] From the results in Table 1, the artificial diamond-coated indexable positive tips of the present invention produced in Examples 1 to 5 are superior to the conventional artificial diamond-coated indexable positive tips produced in the above comparative examples. The diamond-coated indexable tip of the present invention requires a large number of passes before cracking or peeling occurs in the artificial diamond coating layer, and thus can provide an artificial diamond-coated indexable tip with a longer lifespan than conventional ones. When cutting with a tip, the number of times the tip is replaced can be reduced and work efficiency can be greatly improved.

In this embodiment, an artificial diamond-coated indexable positive tip is described in detail, but the present invention is not limited thereto, and similarly excellent effects can be achieved with an artificial diamond-coated indexable negative tip.

[Brief explanation of drawings]

Figures 1 to 5 are perspective views of the artificial diamond-coated indexable positive tip of the present invention, and Figures 2-1 to 5-5.
Figure 1 is a perspective view showing the indexable positive chip base material covered with Ta foil or Ta tape, Figure 6 is a partial cross-sectional view of the graphite substrate used when forming the artificial diamond coating layer, 7 and 8 are perspective views of the artificial diamond-coated indexable negative chip of the present invention. DESCRIPTION OF SYMBOLS 1... Artificial diamond coating layer, 2... Throwaway chip base material, 3... Pit, 4... Graphite substrate, 5... Non-forming part,
6...Mounting hole, 7...Metal foil, 8...
...Metal tape.

Claims (5)

[Claims] (1) In the artificial diamond-coated indexable tip, an artificial diamond coating layer is formed on at least the cutting action part of the indexable tip base material, and a non-formed part without the artificial diamond coating layer is formed on the part other than the cutting action part. An artificial diamond-coated indexable tip comprising: (2) In the artificial diamond-coated indexable positive insert, an artificial diamond coating layer is formed on at least the cutting action portion of the indexable positive insert base material, and the cutting action portion is on the entire lower surface and side surface of the indexable positive insert base material. An artificial diamond-coated indexable indexable tip, characterized in that the tip has a non-formed part without an artificial diamond coating layer. (3) In the artificial diamond-coated indexable positive insert, an artificial diamond coating layer is formed on at least the cutting action portion of the indexable positive insert base material, and the artificial diamond coating layer is formed on the entire lower surface of the indexable positive insert base material, and on the top and side surfaces of the indexable positive insert base material. An artificial diamond-coated indexable indexable insert characterized by having a non-forming part without an artificial diamond coating layer in a part other than the cutting action part. (4) In the artificial diamond-coated indexable negative tip, an artificial diamond coating layer is formed on at least the cutting action portion of the indexable negative chip base material, and the cutting action on the top, bottom and side surfaces of the indexable negative chip base material is reduced. An artificial diamond-coated throw-away negative chip characterized by having a non-formed part without an artificial diamond coating layer in a part other than the part. (5) In the method for manufacturing an artificial diamond-coated indexable tip, when coating the surface of the indexable tip base material with artificial diamond, part or all of the indexable tip base material other than the cutting action part is covered with a Ta thin plate. A method for manufacturing an artificial diamond-coated indexable tip characterized by covering the tip.