KR19980059980A - Cutting coated carbide tool and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a cutting tool that improves the service life by removing the residual stress inside the coating layer coated on the cutting tool base material surface, increasing wear resistance and toughness, and the TiCN layer according to the temperature-temperature chemical vapor deposition method on the base material surface. The present invention relates to a cutting coated cemented carbide tool obtained by coating a TiC layer and a metal oxide layer according to a high temperature chemical vapor deposition method, and a method of manufacturing the same.

Description

Cutting coated carbide tool and manufacturing method thereof

The present invention relates to a coated cemented carbide insert used as a tool material for metal cutting, and more particularly, to remove the residual stress inside the coating layer by coating the coating layer coated on the surface of the cutting tool base material by lamination by medium temperature and high temperature chemical vapor deposition. The present invention relates to a cutting-coated cemented carbide tool suitable for improving adhesiveness and improving service life due to wear resistance and toughness.

Generally, cutting tools are used for cutting materials such as iron and steel (alloy steel), and various metal oxides and carbides are coated on the surface of the supply base material by chemical vapor deposition for better wear resistance and toughness.

Conventional chemical vapor deposition methods include high temperature chemical vapor deposition and medium temperature chemical vapor deposition.

In the chemical vapor deposition method, a gas mixture containing titanium tetrachloride, nitrogen, methane, hydrogen, gas, and the like is reacted with a cemented carbide base material at a temperature of about 900 ° C to 1100 ° C, and a titanium compound, TiC, TiCN, TiN, etc., is used as a coating layer. The upper surface is made of alumina (or aluminum oxide), which is a kind of ceramic, as a coating layer by reacting gases such as AlCl ₃ and CO ₂ .

The coating layer made of the titanium compound may be made of two layers. For example, although a TiN layer is used as one layer and a TiCN layer is used as two layers, these layers can also be changed.

The laminated structure according to the high temperature chemical vapor deposition method is applied to wear-resistant tools or carbide tools to improve the cutting performance and tool life to some extent, but by applying the coating at high temperature, unwanted hard phases on the boundary between the coating layer and the base material interface An eta (eta) phase compound is formed, which adversely affects tool life, resulting in a reduction of the application area.

The eta phase compound has high hardness but is brittle, and reduces adhesion between the base material and the coating layer.

Therefore, there is a drawback that the adhesive force is lowered and the toughness of the tool is lowered, thereby failing to function as a cutting tool.

In order to improve the above-mentioned defects, the present inventors coat the TiCN layer 3 on the surface of the base material 1 according to the chemical vapor deposition method, which is 700 to 900 ° C, and a high temperature of 900 to 1100 ° C on the upper surface thereof. Based on the chemical vapor deposition method, the technology of coating the Al ₂ O ₃ layer (5) has been filed in the domestic patent application No. 96 ~ 1603 (hereinafter referred to as the prior art).

However, the above-described technology has a large difference in thermal conductivity and coefficient of thermal expansion between the two coating layers, and thus has a residual stress inside the coating layer, thereby affecting the cutting tool life due to the lack of adhesion.

The present invention has been made in order to improve the above-mentioned conventional problems, by inserting another coating layer between the two coating layers of the prior art by removing the residual stress in the coating layer of the alloy tool having a high adhesiveness, laminated structure excellent in wear resistance To get that purpose.

1 is a cross-sectional view of a conventional laminated structure.

2A is a cross-sectional view of a clad laminate structure according to the present invention.

Figure 2b is a cross-sectional view showing a coating laminated structure according to another embodiment of the present invention.

Figure 3a is a graph showing the wear resistance test in the case of dry cutting the workpiece (SKT4) using the present invention.

3B is a graph showing abrasion resistance test in the case of wet cutting the workpiece (SKT4) using the present invention.

Figure 4 is a graph showing the fracture resistance test in the case of dry cutting the workpiece (SKT4) using the present invention.

Explanation of symbols for main parts of the drawings

1: Base material 2: TiN layer

3: TiCN layer 4: TiC layer

5: Al ₂ O ₃ layer

In order to achieve the above object, in the present invention, as shown in FIG. 2A, the TiCN layer 2, the TiN layer 3, and the Al ₂ O ₃ layer 4 are formed on the surface of the base material 1. As shown in FIG. 2B, the TiN layer or the TiCN layer 2 is formed between the base material 1 and the TiCN 3.

In the above laminated structure, each thickness is preferably in the range of 0.1 to 15 μm of TiCN, 0.5 to 5.0 μm of the TiN layer, and 0.1 to 3.0 μm of the metal acid compound layer.

The base material used in the present invention can be applied to other cemented carbides composed of WC, TaC, TiC, CO, etc., and any applicable material can be applied as long as it can coat the titanium compound on the surface of the base material.

Therefore, the base material composition is not limited to any one.

The metal oxide laminated on the titanium compound layer may include Al ₂ O ₃ as an example.

In the coating treatment to have the laminate structure described above, first, the surface of the base material 1 is coated to a TiCN layer 3 having a thickness of 0.1 to 15 μm by using a chemical vapor deposition method (around 700 to 900 ° C.), and a high temperature. The chemical vapor deposition (approximately 900 to 1100 ° C) is used to coat the TiC layer 4 having a thickness of 0.5 to 5 µm and the metal oxide layer 5 having a thickness of 0.1 to 3.0 µm.

In addition, the present invention can form a TiN layer (2) or TiCN layer between 0.1 to 1.0㎛ thickness between the base material (1) and the TiCN layer (3) by a high temperature chemical vapor deposition method.

The following is described according to the embodiment.

The cemented carbide cutting material, the specification of SPKN 1203DETR, was coated under the conditions shown in Tables 1, 2, and 3 below.

Table 1 shows the coating (TiCN layer, Al ₂ O ₃ layer) conditions using the conventional high temperature chemical vapor deposition method (Sample 1), Table 2 shows the coating (TiCN) conditions and high temperature chemical vapor deposition method according to the conventional medium temperature chemical vapor deposition method According to the coating (Al ₂ O ₃ ) conditions (Sample 2), Table 3, the present invention, the coating according to the medium temperature chemical vapor deposition (TiCN) and the coating according to the high temperature chemical vapor deposition (TiC layer, Al ₂ O ₃ layer) The condition is shown.

Table 4 shows the coating layer thickness according to the above conditions.

In these coating conditions, only important steps are presented for mutual contrast, and short transition steps between each step are omitted and simplified.

The base material is a cemented carbide composed of WC, TaC, TiC, and CO, and all were the same for each condition.

Milling cutting test was performed on the three coated specimens Tables 1 to 3 to compare the performance.

In general, the performance comparison was performed by the milling cutting method, and the fracture resistance test was performed under the condition that the tool was severely impacted.

TABLE 1

Conventional High Temperature Chemical Vapor Deposition (TiCN Layer, Al ₂ O ₃ Layer) (Sample 1)

TABLE 2

Conventional Medium and High Temperature Chemical Vapor Deposition (Psalm 2)

TABLE 3

Deposition method according to the invention

TABLE 4

Coating layer thickness at each condition

Abrasion resistance test

In the comparative test, the cutting conditions were cut dry and wet with the cutting speed of 180mm / min, feed rate of 0.1mm / tooth and depth of cut of 2.0mm when the workpiece was made of SKT 4 material.

The maximum amount of wear (Frank wear) on the side of the tool is expressed as Vb max, indicating that the lower the amount of wear, the better the wear resistance.

3A and 3B show the test results, the former being a dry cut and the latter being a wet cut.

3A and 3B, it can be seen that specimens 2 (linear technology) and specimens 3 (invention) have better abrasion resistance than specimens 1 (conventional), which are coated under the high temperature chemical vapor deposition method under the coating layer. It can be seen that the eta (η) phase, which is a weak intermetallic compound, is formed to reduce adhesion between the base material and the coating layer during the cutting test.

Comparing specimen 3 with specimen 2, it can be seen that the present invention is excellent.

This can be seen that it is due to the TiC similar to the Al ₂ O ₃ layer to increase the adhesion by removing the residual stress in the coating layer, which is a disadvantage of the specimen 2.

A defect test

The fracture resistance test was performed with the same SKT 4 workpiece as the abrasion resistance test with a cutting speed of 90 m / min and a depth of cut of 2.0 mm, and was carried out dry four times while increasing the feed amount from 0.14 mm / tooth to several steps.

As a result, it was found that the present invention (Psalm 3) is excellent as shown in FIG.

As described above, the present invention forms a TiC layer according to the medium temperature chemical vapor deposition of the tool base material surface, a TiC layer according to the high temperature chemical vapor deposition, and an Al ₂ O ₃ layer, thereby improving the adhesion by removing the internal residual stress between the coating layers. It is possible to secure a cutting coated cemented carbide tool having an effect of forming a service life according to increased wear resistance.

Claims (8)

A cemented carbide tool for cutting, characterized in that the TiCN layer, the TiC layer, and the metal oxide layer are sequentially laminated on the cemented carbide tool surface. The coated cemented carbide tool according to claim 1, wherein the TiCN layer has a thickness of 0.1-15.0 µm, the TiC layer has a thickness of 0.5-5.0 µm, and the metal oxide layer has a thickness of 0.1-3.0 µm. The coated cemented carbide tool according to claim 1 or 2, wherein a TiN layer or a TiCN layer is formed between the base material surface and the TiCN layer. _{3. The} coated cemented carbide tool according to claim 1 or 2, wherein the metal oxide layer is Al ₂ O ₃ . Cemented carbide tool The method of manufacturing a coated cemented carbide tool characterized in that the coating of the TiCN layer on the surface of the base metal substrate by using a medium temperature chemical vapor deposition method, and sequentially coating the TiC layer and the metal oxide layer using a high temperature chemical vapor deposition method. The method of claim 5, wherein the TiCN layer is coated with a thickness of 0.1 to 15.0 µm, the TiC layer is 0.5 to 5.0 µm, and the metal oxide layer is 0.1 to 3.0 µm. The method of claim 5, wherein the surface of the base material is coated with a TiN layer or a TiCN layer by using a high temperature chemical vapor deposition method, and then coated with a TiCN layer by a medium temperature chemical vapor deposition method. 7. The method of claim 5 or 6, wherein the metal oxide is Al ₂ O ₃ .