JPS6220862A - Production of surface coated sintered hard alloy member - Google Patents

Abstract

PURPOSE:To develop a surface coated sintered hard alloy member having high resistance to exfoliation and wear by preliminarily coating the film of the carbide, nitride, carbonitride, carbonitrooxide or carbonate of Ti on the surface of a sintered hard alloy for a cutting tool and wear resistant tool then forming a regular coating layer thereon. CONSTITUTION:The cutting tool and wear resistant tool made of the sintered hard alloy formed by sintering the hard materials such as the carbide, nitride or boride of various metals with Co, Ni, etc., are put into a vacuum vessel into which gaseous carbide, gaseous N2, gaseous CO, etc., are introduced and the tools are heated for 2-30min at 850-950 deg.C to preliminarily coat the hard layer consisting of TiC, TiN, TiCN, TiCNO, TiCO or the like thereon. The hard layer consisting of TiC, etc., is then regularly coated thereon by a physical vapor deposition method using the above-mentioned gases in the mid-way or after the temp. decrease down to 750-850 deg.C to form the hard Ti compd. layer to 0.5-10mum as a whole. The coating layer has the high adhesivess to the sintered hard alloy and does not exfoliate therefrom. Since said layer has the excellent hardness as well, the service life of the sintered hard alloy tool for cutting, etc., is extended.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a surface-coated cemented carbide member for cutting tools and wear-resistant tools, in which a hard coating layer is formed on the surface, and in particular, A method for producing surface-coated cemented carbide members for durable cutting tools and wear-resistant tools, which have a hard titanium compound coating layer formed on the surface, using a reactive physical vapor deposition method. It is.

[Conventional technology]

Conventionally, Ti, Zr + Hf + V, Nh + Ta
Hard powder such as carbide, nitride, boride or silicide of +Cr +Mo +W+Th;'6, Co
, So-called cemented carbide, which is sintered at high temperatures using metals such as Ni as a binder, is highly hard and heat resistant, so it is widely used as a material for various cutting tools and wear-resistant tools. However, if a hard covering layer made of a titanium compound such as titanium carbide or titanium nitride is provided on the surface of this cemented carbide, the welding resistance, seizure resistance, and wear resistance will be improved, dramatically extending the tool life. Due to its long length, it has recently become widely used industrially to provide such a coating layer on the surface of cemented carbide.For example, carbonization of about 2 μm on the surface of the indexable chip is applied using reactive physical vapor deposition. Cemented carbide parts for cutting tools and wear-resistant tools having a surface coating layer of titanium carbide or titanium nitride, for which coating tips coated with a titanium or titanium nitride layer are widely used, can be produced using a reactive physical vapor deposition method. First, the cemented carbide substrate was heated to a temperature of 400 to 700 °C in a vacuum atmosphere at a pressure of 10 to 10 Torr, and then heated to a pressure of 10 to 10 Torr with argon).
After optionally applying etching to this substrate, the temperature and pressure are continued to be maintained to cause a reaction with titanium carbide or titanium nitride, that is, titanium metal evaporated by an electron beam or the like and in a coating furnace. The supplied acetylene or nitrogen gas is ionized to form Ti+ and C+, respectively, and these ions are electrically attracted onto the negatively charged substrate to form a coating made of titanium carbide or titanium nitride, respectively, on the surface of the substrate. It is manufactured by forming.

[Problem that the invention seeks to solve]

However, when a titanium compound such as titanium carbide or titanium nitride is coated on a cemented carbide substrate at 400 to 700°C as described above, direct contact between the coating layer formed by these titanium compounds and the cemented carbide substrate occurs. Since almost no bonding and diffusion of the coating layer to the substrate occurs, the coating layer has poor adhesion, and the surface-coated cemented carbide cutting tools and wear-resistant tools obtained in this way tend to peel off during use. The drawback is that the tool life is short.

[Research-Based Knowledge] Therefore, the inventors of the present invention have conducted various studies to solve such melting problem, and as a result, (1) titanium carbide, titanium nitride, titanium carbonitride, titanium carbonitride oxide, and Titanium carbonate (hereinafter referred to as TiCr TiN + T1CN + TiC'NO and TiC0, respectively, and for convenience, they are collectively referred to as titanium carbon/nitrogen/oxide) is made into a superhard material by a reactive physical vapor deposition method. When coating an alloy substrate, increasing the substrate temperature increases the direct reaction between the substrate and the coating layer and the diffusion of the substrate into the coating layer, which does not reduce the toughness of the substrate, thereby improving the adhesion between the two. (21) If the temperature of the substrate is extremely increased or the increased temperature is maintained for a long time, the IpA of the substrate will increase.
f! ! Since the η phase that lowers F is generated inside the substrate, the temperature is 850-950°C and the coating time is 2-950°C.
30 minutes is suitable; (3) Although the above coating does not provide a coating layer with a thickness of +/-, this is used as a preliminary coating, and then the main coating is applied to the preliminary coating formed by this preliminary coating. By forming this coating layer with a total thickness of 0.5 to 10 μm on the coating layer, a coating layer with excellent adhesion as a whole can be obtained, resulting in a cutting tool with a dramatically extended tool life. (4) Even if the substrate temperature during the main coating applied after the preliminary coating is slightly higher than before, there will be no adverse effect on the cemented carbide. (5) After the completion of the preliminary coating, the main coating is applied while lowering the temperature from the temperature of the preliminary coating. It has been found that a coating layer with excellent adhesion can be obtained as described above even when the coating is started.

[Means for solving problems]

This invention was invented based on the above knowledge, and utilizes a reactive physical vapor deposition method to produce a material selected from titanium carbide, titanium nitride, titanium carbonitride, titanium carbonitride oxide, and titanium carbonate. A surface for a cutting tool or a wear-resistant tool on which a coating layer made of the nucleated component is formed by coating one of the coating components on a cemented carbide substrate for a cutting tool or a wear-resistant tool. In the method for producing a coated cemented carbide member, the substrate is heated to a temperature of 2,850 to 950° C. in a vacuum, and then immediately pre-coated with the coating component on the substrate at this temperature for 2 to 30 minutes, A pre-coating layer made of the nucleated component is formed on the surface of the substrate, and then the temperature of the pre-coated substrate is lowered to a temperature of 750 to 800° C., or during and after the temperature decrease, the A main coating layer consisting of the coating component is formed on the surface of the preliminary coating layer by main coating the same covering component as that used to form the preliminary nucleation layer, thereby forming a main coating layer consisting of the coating component on the surface of the preliminary coating layer. The surface-coated carbide for cutting tools and wear-resistant tools, characterized in that a coating layer consisting of the preliminary coating layer and the main coating layer and having a total thickness of 0.5 to 10 μm is coated on the substrate. A method for manufacturing an alloy member is provided.

Next, the reason why the pre-coating temperature, pre-coating time, main coating temperature and coating layer thickness are each limited as described above in this invention will be described.

(Kaede) Pre-coating temperature If the pre-coating temperature is less than 850°C, the direct reaction between the pre-nucleation layer and the substrate and the diffusion of the coating layer into the substrate will not be achieved sufficiently, so that the desired fixation between the two will not be achieved. On the other hand, if it exceeds 950℃, the substrate will have η
The pre-coating temperature was set at 850 to 950°C since phases were formed and the toughness was reduced.

(hl Pre-coating time) If the pre-coating time is less than 2 minutes, even if the substrate is raised to the above-mentioned pre-coating temperature, there will be no direct reaction between the pre-coating layer and the substrate and the diffusion of the nine layers into the substrate. Because the adhesion does not proceed sufficiently, the desired adhesion cannot be obtained between the two, and on the other hand, if it exceeds 30 minutes, an η phase is formed on the substrate and its toughness decreases even if the substrate is kept at the above temperature. Therefore, the above-mentioned time was set to 2 to 30 minutes.

fcl Main coating temperature In general, the smaller the difference between the substrate temperature during main coating and that during pre-coating, the better the compatibility between the preliminary nucleation layer and the main coating layer, resulting in a highly durable covering layer. At the same time, even if the coating temperature is slightly higher than in the past, there will be no adverse effect on the cemented carbide, so instead of the conventional coating temperature of 400 to 700°C, in this invention the coating temperature is increased to 750 to 750°C.
The temperature was set at 800°C.

fdl Thickness of the covering layer If the total thickness of the covering ω layer is less than 0.5 μm, surface-coated cemented carbide members for cutting tools and wear-resistant tools that exhibit excellent cutting performance or wear resistance, respectively, cannot be obtained. On the other hand, it is 1
Even if the thickness exceeds 0 μm, no particular improvement effect can be obtained in terms of cutting performance or wear resistance, so the thickness was reduced to 0 μm.
．． It was determined to be 5 to 10 μm.

The present invention is accomplished by anti-gS physical vapor deposition, which is commonly used to deposit titanium carbon-nitrogen-oxide coatings on cemented carbide substrate surfaces. A gas such as carbon oxide is introduced into the furnace, which is maintained at a pressure of 10 to 10 Torr, and metal titanium is evaporated using an electron beam or the like, and these reactive components are ionized using an electric discharge phenomenon. to generate ions such as Ti+I N+I C+I O+, and the cholera cations are deposited by electrical attraction onto a negatively charged cemented carbide substrate, thereby depositing titanium charcoal on the surface of the substrate. Forms a nitride/oxide film.

The present invention can be applied to the production of surface-covered parts for various cutting tools and wear-resistant tools, but is particularly applicable to cutting tools such as throw-away tips, end mills, and drills, and wear-resistant tools such as punches and barrels. It can be advantageously used for manufacturing.

〔Example〕

Next, the present invention will be explained by examples and in comparison with comparative examples.

A large number of throw-away chips with a shape of JIS 5Np432 were manufactured from a cemented carbide with a composition of 1096WC-10%TiC5%'rac-co, and these chips were used as a base in a coating furnace maintained at a vacuum of 10 Torr. After raising the temperature of this substrate to a temperature between 850 and 950 ° C., immediately pre-coating any one of titanium carbon, nitrate, and oxide on the surface of the substrate for 5 to 20 minutes at this temperature, Next, after lowering the temperature of the substrate to 750 to 800° C., coated chips 1 to 8 of the present invention are manufactured by main coating with the same coating components as those used in the preliminary coating, and as an alternative method of the method of the present invention, The only points in the manufacturing method are that the main coating is started while the substrate temperature is lowered to 750 to 800°C, and that etching with argon is performed for 10 minutes at a substrate temperature of 2,850 to 950°C before pre-coating in the manufacturing method. Coated chips 9 and 10 of the present invention were manufactured by methods different from the above-mentioned manufacturing methods, respectively.

Furthermore, for comparison, the coating chips 1 to 1 of the present invention
Comparative coating chips 1 and 2 were manufactured using a manufacturing method in which the manufacturing conditions were outside the scope of the present invention (deviating conditions are indicated by a pot symbol), and 10=T□rr The conventional method involves raising the temperature of the substrate to 700°C in an overheating furnace maintained at a vacuum level of 100°C, etching the substrate with argon at the same temperature, and then coating it with carbon, nitride, and oxide of titanium at that temperature. Conventionally coated chips 1 to 5 were manufactured by the following method.

In each of the above methods, during etching, the substrate voltage: -1.5KV, Ar pressure crab: 10-2T
orr, and the substrate voltage during coating: −O,
It was SKV.

The reaction gas for forming the coating layer of each titanium compound and the furnace pressure during coating were as shown in Table 1 below.

Table 2 shows the manufacturing method type, preliminary coating temperature and time, main coating temperature, and coating layer components and thickness for each chip thus obtained.

Next, these chips and uncoated chips were observed for the presence or absence of the η phase generated inside their substrates, and the following conditions (
A cutting test was conducted according to the following formula, and the cutting time until the VB wear reached 0.3 cm was measured, and this was taken as the tool life.

Cutting conditions Work material: SNCM439. HB: 250° holder two NI
IR-44.

Cutting speed g: V-100m/min, d=4w
.

f = 0.45 w/reV,.

The above results are summarized in Table 2.

〔Effect of the invention〕

From the results shown in Table 2, the tool life of conventionally coated inserts is 15 to 30 minutes, and 1.4 and 5 minutes.
The coating layer peeled off during cutting with the coated chips of the present invention, whereas the coating layer did not peel off during cutting with the coated chips of the present invention, and the tool life was dramatically increased to 120 to 155 minutes. Comparative coatings Steps 1 and 2, which were produced by methods in which the .

As is clear from the above description, according to the present invention, it is possible to obtain a surface-coated cemented carbide member for cutting tools and wear-resistant tools that has extremely excellent wear resistance and therefore has an extremely long tool life.

Claims (1)

[Claims] Using a reactive physical vapor deposition method, one coating component selected from titanium carbide, titanium nitride, titanium carbonitride, titanium carbonitride, and titanium carbonate is applied to cutting tools and wear-resistant tools. A method for manufacturing a surface-coated cemented carbide member for a cutting tool or a wear-resistant tool in which a coating layer made of the coating component is formed on the surface by coating a cemented carbide substrate for use in the substrate. After raising the temperature to 850 to 950°C in vacuum, immediately pre-coat the coating component on the substrate at this temperature for 2 to 30 minutes to form a pre-coating layer made of the coating component on the surface of the substrate. Then, after the temperature of the pre-coated substrate is lowered to 750 to 800° C., or during and after the temperature decrease, the same coating component as that used to form the pre-coating layer is applied. is coated on the pre-coating layer to form a main coating layer consisting of the coating component on the surface of the pre-coating layer, thereby increasing the overall thickness of the pre-coating layer and the main coating layer. : A method for manufacturing the surface-coated cemented carbide member for cutting tools and wear-resistant tools, which comprises coating the substrate with a coating layer of 0.5 to 10 μm.