JPS5944385B2 - Coated cemented carbide parts - Google Patents

Description

Detailed description of the invention Ti, Z, Hf, V, Nb, Ta, C, Mo, W, one or more carbides and/or carbonitrides, mainly iron group metals. Combined with one or more of the following:

Coated cemented carbide parts have a cemented carbide component as a base material and coat the surface with highly wear-resistant TiC, TiN, etc., and have both the wear resistance of the surface and the toughness of the base material. It is widely used as a cutting tool superior to conventional cemented carbide members. An object of the present invention is to provide an even more excellent coated cemented carbide member. The most important property required of the coating material is high hardness under extremely high temperatures (usually around 1000° C.) to which the cutting edge of a tool is exposed during actual cutting. From this point of view, diborides of Ti, Zr, and Hf, which have extremely high hardness at high temperatures, are most preferable, especially TiB2, but in reality, these diborides react with iron, which is the work material, and Crater wear progressed significantly, which was not desirable. After various studies on how to suppress this reaction with iron, we found that Ti, Zr, Hf
We focused on the fact that nitrides, especially TIN, have poor reactivity with iron and cause very little crater wear. However, T
Since iN has poor high-temperature hardness, it was thought that using a material exhibiting properties intermediate between TiN and TiB2 would satisfy both high-temperature hardness and reactivity with iron. When we actually investigated the state of TiN and TiB2 by making various prototypes using the chemical vapor deposition method, we found that in the vicinity of 1000°C, there is usually a two-phase mixed region of Ti(BN) and TiB2, and a single phase of Ti(BN). It turns out that there is an area.

A schematic state diagram is shown in FIG. When we actually produced a prototype based on this idea, we obtained the expected effect. Regarding the limit on the amount of TiB2, if TiB2 exceeds 50% of the total amount, the reaction with iron, which is the work material, cannot be ignored, which is not preferable. Furthermore, regarding Ti (BN), even if some of its non-metal constituent elements were replaced with carbon, no essential difference in effect was observed.

Although the above description has been made using Ti as an example, it has been found that Zr and Hf have similar effects.

Furthermore, there was almost no difference in effectiveness even with the presence of small amounts of impurities and additives. In addition, when the coating layer is used as a single layer of multiple coating layers, such as in a so-called multi-coated cemented carbide, a synergistic effect appears. In particular, the surface of the coated cemented carbide member is made oxidation resistant, and aluminum oxide, which is the richest in aluminum oxide, provides a synergistic effect. When coated, the oxidation resistance of the cutting tool was significantly improved and even more favorable effects were obtained.

Although it is most preferable to use a chemical vapor deposition method to produce the present invention, physical vapor deposition methods such as ion plating, sputtering, and vacuum evaporation, plasma spraying,
It can also be manufactured by metallizing, such as flame spraying. This will be explained in detail in Examples below.

Example 1 A 1SOP-30 cemented carbide member (model number SNU432) was heated and maintained at 1000° C. in a mixed gas flow of boron trichloride, titanium tetrachloride, nitrogen, and hydrogen.

After cooling, the surface was analyzed by X-ray diffraction and the result was TiB23O.
It was found that two phases of 70% by weight Ti(BN) were present. A cutting test was conducted using this chip and a commercially available TiC-coated chip for comparison under the following conditions. As a result of cutting tests, the chip of the present invention had a crater wear of 0.04 m7! L, blank wear was 0.18 mm, whereas with the commercially available TiC coated chip, crater wear was 0.141 L1 L1 blank wear was 0.36 mm. Example 2: Exactly the same cemented carbide member as Example 1. 1000 in a mixed stream of methane, boron trichloride, titanium tetrachloride, nitrogen, and hydrogen.
The temperature was maintained at ℃.

After cooling, analysis was performed in the same manner as in Example 1, and TiB2
It was found that two phases of 30% by weight and 70% by weight of Tl(BNC) were present. When this chip was subjected to a cutting test under the same conditions as in Example 1, the crater wear was 0.10.
The blank wear was 0.1711. Example 3 The same cemented carbide member as in Example 1 was coated with various coatings in the same steps as in Example 1.

A cutting test was performed on them under the following conditions, and the crater wear was 0.15 mm or the blank wear was 0.40 mm.
It was determined that the lifespan reached the end of m. The results and the composition of the coating layer are shown in Table 1. In the table, A, B, and C are products of the present invention, and D, E, F, and G are comparative examples. Example
4 Exactly the same as Example 1 30 (fl) TlB2-70%T
The i(BN) coated cemented carbide member was coated with aluminum oxide by heating and holding at 85°C in a mixed flow of aluminum trichloride, hydrogen, and carbon dioxide.

For comparison, a cutting test was conducted using the chip of the present invention, the chip of Example 1, and a commercially available TLC-coated chip under the following conditions.

The tip of the present invention without using any cutting agent could cut for 41 minutes, whereas the tip of Example 1 and the commercially available TLC-coated tip could cut for 9 minutes and 4 minutes, respectively, due to crater wear. The only thing I could do was cut it.

[Brief explanation of the drawing]

FIG. 1 is a phase diagram of TiN-TiB2 condensed two elements at 10,000C.

Claims (1)

[Scope of Claims] 1 50% by weight or less of diboride of one or more of Ti, Zr, and Hf and 50% by weight of boronitride and/or borocarbonitride of one or more of Ti, Zr, and Hf A coated cemented carbide member, characterized in that the mixture consisting of the above or the above compound not containing diboride is coated on the cemented carbide member as one coating layer. 2. A mixture consisting of 50% by weight or less of Ti diboride and 50% by weight or more of Ti boronitride and/or borocarbonitride, or the above Ti compound containing no diboride is used as a coating layer on a cemented carbide member. The coated cemented carbide member according to claim 1, wherein the coated cemented carbide member is coated in a single layer. 3 A mixture or diboride consisting of 50% by weight or less of one or more diborides of Ti, Zr, and Hf and 50% or more of boronitride and/or borocarbonitride of one or more of Ti, Zr, and Hf. A coated cemented carbide member, characterized in that the compound containing no boride is coated on the cemented carbide member as one layer of the coating layer, and Al_2O_3 is coated as the outermost coated layer. 4 A mixture consisting of 50% by weight or less of Ti diboride and 50% by weight or more of Ti boronitride and/or borocarbonitride, or the above Ti compound containing no diboride is used as a coating layer on a cemented carbide member. The coated cemented carbide member according to claim 3, characterized in that the coated cemented carbide member is coated as a single layer and is coated with Al_2O_3 as the outermost coated layer.