JPH03260062A - Production of ceramic-coated member - Google Patents

Abstract

PURPOSE:To prevent the release of a ceramic layer from a metallic base material due to thermal stress by providing a specified metallic intermediate layer on the base material, forming a layer of the alloy of both metals in between and then forming a ceramic layer on the intermediate layer. CONSTITUTION:The piston of an engine, etc., is produced from an Al alloy excellent in machinability and toughness. At this time, a ceramic 4 of the SiC, Si3N4, TiC, TiN, etc., excellent in high-temp. strength and wear resistance is formed on the Al alloy 1 as the base material by ion plating method to improve the high-temp. strength and wear resistance of the piston base material. In this case, an intermediate layer 3 of metals such as Ti, Zr and Hf is formed on the Al alloy base material 1 surface by ion plating method and heated, and an alloy layer 2 of both metals 1 and 3 is formed in between by the ion mixing method. A hard ceramic layer 4 of SiC, TiC, Si3N4, TiN, etc., is formed on the layer 3 by ion plating method, and the reaction product layer 5 of the ceramic 4 and intermediate layer material is formed in between. The release of the ceramic layer 4 from the base material 1 due to the thermal stress caused by the difference in the thermal expansion coefficient is prevented in this way.

Description

Detailed Description of the Invention (Field of Application in Industry A) The present invention relates to the production of ceramic coated members in which the surface of the member made of metal material dregs is coated with ceramics through an alloy layer that buffers thermal stress. Regarding the method.

(Prior Art) Metal materials are widely used as materials for members, and various metal materials are used, for example, as engine members.

However, although metal materials have excellent machinability and toughness, as the performance of engines and the like improves and the conditions required for components become stricter, materials with even better wear resistance are required.

On the other hand, although ceramic materials have a low specific gravity and are excellent in high-temperature strength and wear resistance, their low toughness imposes many restrictions on their use as materials for parts, and they are not used in some parts. There are only

Therefore, a method has been proposed to improve wear resistance by coating the surface of a member made of a metal material with ceramic. A method for manufacturing a bearing characterized by ion plating is described in Japanese Patent Application Laid-open No. 57869.

(Problem to be Solved by the Invention) By the way, the coefficient of thermal expansion of aluminum alloy, which is a metal material, is 22×10-6/, while the coefficient of thermal expansion of the ceramic material coated on the surface of the metal material is 3. ~8X
It is 10-6/.

Furthermore, when a ceramic material is coated using the above-mentioned conventional manufacturing method, the metal material constituting the base material cannot be heated to a very high temperature, so the processing temperature during coating cannot be increased, and the metal part The two do not react at the interface between the ceramic part and the ceramic part.

Therefore, since the composition changes sharply at the interface, if the component is used in an environment subject to thermal cycles, there is a problem that the metal part and the ceramic part will separate at the interface because the thermal expansion coefficients of the two differ. There is.

(Means for Solving the Problems) The present invention has been made in view of the above points, and is to manufacture a ceramic coated member in which the metal part and the ceramic part do not peel off even when used in an environment C that is subject to thermal cycles. It is intended to provide a method.

A method of manufacturing a ceramic coated member according to the present invention will be explained with reference to FIG.

FIG. 1 is a diagram illustrating the steps of the present invention.

In step 1, the surface of a base material made of a metal material such as an aluminum alloy is cleaned, and then in step 2, a metal element such as titanium is deposited on the surface of the base material to form an intermediate layer.

Next, in step 3, the base material on which the intermediate layer is vapor-deposited is heated or an ion mixing method is used in which accelerated argon ions are irradiated to coat the bonding surface between the base material and the intermediate layer with aluminum-titanium, etc. form an alloy layer.

After forming the alloy layer, the surface of the intermediate layer is cleaned, and in step 4, a ceramic such as titanium nitride is deposited to form an adhesion layer.

(Function) In the method for manufacturing a ceramic coated member of the present invention, the thermal expansion coefficient of the alloy layer interposed between the base material and the adherend layer is the thermal expansion coefficient of the metal material constituting the base material and the adherend layer. Since the coefficient of thermal expansion is approximately midway between that of the ceramic forming the material, it has the effect of relieving the concentration of thermal stress between the base material and the adherend layer during thermal cycling.

(Example) Examples of the present invention will be described in detail below.

Example 1 After cleaning the surface of a base material made of an aluminum alloy with acetone, the base material was placed in a vapor deposition apparatus with a reduced pressure of 10-6 Torr, and the surface of the base material was further cleaned by irradiation with argon ions.

Then, titanium was heated and evaporated in the vapor deposition apparatus and deposited on the surface of the substrate to form an intermediate layer.

Next, the base material on which the intermediate layer has been formed is taken out from the vapor deposition apparatus and placed in a vacuum furnace, and then the base material is placed in a vacuum atmosphere for 35 minutes.
It was heated to 0° C. to form an aluminum-titanium alloy at the boundary between the base material and the intermediate layer to form an alloy layer.

After forming the alloy layer, it was taken out of the vacuum furnace and then placed in an ion plating apparatus.

After cleaning the surface of the intermediate layer by irradiating argon ions, argon gas is used as a carrier and nitrogen gas is introduced into the apparatus as a reaction gas to nitridize the surface of the intermediate layer and remove the adhesion layer made of titanium nitride. formed.

Sample A manufactured by the above steps was cut and the composition etc. were analyzed and the results will be explained with reference to FIG. 2.

FIG. 2 is a partial cross-sectional view of sample A.

1 is a base material, 2 is an alloy layer, 3 is an intermediate layer, and 4 is an adhesion layer. Note that 5 is a reaction layer in which titanium of the intermediate layer 3 and titanium nitride of the adhesion layer 4 react and coexist.

It was confirmed that crystallized layers from alloy layer 2 to adhesion layer 4 were formed on the surface of base material 1 with a layer thickness of about 5 μm.

Then, the sample A was heated for about 500°C between 25°C and 250°C.
As a result of applying two thermal cycles, no crack growth was observed at the interface between the layers.

Comparative Example In order to compare with Sample A above, the same base material surface as in Example 1 was cleaned, placed in an ion plating apparatus, and titanium nitride was directly deposited on the surface of the base material.

As a result of cutting the substrate on which the titanium nitride was deposited and observing the boundary between the substrate and the titanium nitride layer, some peeled portions were found.

Next, after performing the same thermal cycle test as in the above example, the boundary portion was observed again, and it was confirmed that the peeled M portion discovered before the thermal cycle test had grown.

Example 2 In the same manner as in Example 1, titanium was deposited on the surface of a base material made of an aluminum alloy to form an intermediate layer having a thickness of about 300 μm.

Next, the base material on which the intermediate layer has been formed is placed inside an ion implanter with a reduced pressure of 10-'Torr, and argon ions are implanted into the ion implanter to push titanium atoms onto the surface of the base material. An alloy layer was formed by mixing 7.

After ion mixing, the intermediate layer is placed in an ion plating device, irradiated with argon ions to clean the surface of the intermediate layer, and then introduced into the device using argon gas as a carrier and ethylene gas as a reaction gas. An adhesion layer made of titanium carbide was formed on the surface.

Sample B manufactured through the above steps was subjected to the same thermal cycle as in Example 1, and as a result, as with sample A, no crack growth was observed at the interface.

Example 3 After forming an alloy layer by the ion mixing method in the same manner as in Example 2, the base material was immersed in a toluene solution of polycarbosilane, which is a polymer precursor containing silicon in its main chain.

After drying, it was heated to 450° C. in an argon atmosphere to form an adhesion layer made of amorphous silicon carbide on the surface of the intermediate layer.

Sample C manufactured by the above steps was subjected to the same thermal cycle as in Examples 1 and 2 above, and as a result, no crack growth was observed at the interface, as in Samples A and B.

Incidentally, in each of the above embodiments, the intermediate layer may be formed by vapor-depositing titanium, zirconia or hafnium, or 2 ffi or more of these, and the adhesion layer may be made of titanium nitride or carbide as shown in the above embodiments. In addition to titanium and silicon carbide, silicon nitride or two or more of these may be used.

Although the embodiments of the present invention have been described in detail above, various different embodiments can be easily constructed without departing from the spirit of the present invention. , and is not limited to any particular implementation.

(Effects of the Invention) As explained above, according to the present invention, the coefficient of thermal expansion of the alloy layer interposed between the base material and the adherend layer is The coefficient of thermal expansion is approximately midway between that of the ceramic that forms the adhesive layer, and it alleviates the concentration of thermal stress between the base material and the adhesive layer during thermal cycling, so it can be used in environments subject to thermal cycling. , provides a method for manufacturing a ceramic coated member in which the base material and the adhered layer do not peel off.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the steps of the present invention, and FIG. 2 is a partial cross-sectional view of sample A. DESCRIPTION OF SYMBOLS 1... Base material, 2... Alloy layer, 3... Intermediate layer, 4...
...Adhesion layer, 5...Reaction layer.

Claims (8)

[Claims] (1) Depositing an intermediate layer made of a second metal element on the surface of a base material made of a first metal element, and heating the base material on which the intermediate layer is deposited to bond the base material and the intermediate layer. A ceramic coated member comprising the steps of: forming an alloy layer made of first and second metal elements on a joint surface; and coating the surface of the intermediate layer with an adhesion layer made of ceramic. Production method. (2) The method for manufacturing a ceramic coated member according to claim (1), wherein the first metal element is at least one of aluminum and iron. (3) The method for manufacturing a ceramic coated member according to claim (1), wherein the second metal element is at least one of titanium, zirconia, and hafnium. (4) The method for manufacturing a ceramic coated member according to claim 1, wherein the ceramic is at least one of titanium nitride, titanium carbide, silicon nitride, and silicon carbide. (5) The method for manufacturing a ceramic coated member according to claim (4), wherein the adhered layer is formed by an ion plating method. (6) The method for manufacturing a ceramic coated member according to claim (1), wherein the ceramic is silicon carbide produced by thermal decomposition of a polymer precursor containing silicon in its main chain. (7) The method for manufacturing a ceramic coated member according to claim (1), wherein the alloy layer is formed by an ion mixing method. (8) The method for manufacturing a ceramic coated member according to claim (1), wherein the base material is an engine piston.