JPS60106961A - Multiple coating method - Google Patents

Abstract

PURPOSE:To carry out satisfactory multiple coating by ion plating by heating a body to be coated to a prescribed temp., coating it to the stripping limit thickness, cooling the coated body once, coating it again after reheating, and repeating the cooling, reheating and coating stages. CONSTITUTION:When a body is coated with ceramics, cermet, a metal or the like by ion plating, the body is heated to a prescribed temp. and coated to the stripping limit thickness. The coated body is cooled once, reheated, and coated again. The cooling, reheating and coating stages are repeated until the resulting coating layers attain to a desired total thickness. The coating layers are not stripped, and since the coating is carried out in vacuum, the layers bond well to each other, forming a thick coating layer.

Description

[Detailed description of the invention] The present invention relates to a method for multilayer coating on the surface of an object to be treated.

When a coating of ceramic, cermet, metal, or the like is formed on the surface of an object to be treated by a vacuum deposition method such as ion blating, it is known that there is a limit to the maximum thickness of the coating depending on the coating material. That is, the thickness is about 10μ for ceramics, about 60μ for cermets, and about 50μ for metals. The reason for this is that the coating may peel off or crack due to internal stress generated on the surface of the coating material during vapor deposition, stress due to differences in thermal expansion coefficients between the base material and the coating, etc. It is.

The present invention was made to break down the conventional concept of maximum coating thickness and increase the maximum coating thickness.
Ceramics and cermets are produced using vacuum deposition methods such as ion blasting.

In a method of multi-layer coating metal on the surface of an object to be treated, the object to be treated is heated to a desired temperature, the coating process is carried out, and the coating process is performed to the peeling limit thickness determined by the coating material and coating conditions. , the temperature of the object to be treated is cooled to room temperature, then the temperature of the coated object is raised again to perform the coating treatment, a film is formed to the peeling limit thickness, and the object is cooled to room temperature; The present invention relates to a multi-coating method characterized in that a film is formed on the surface of an object to be treated by repeating the above steps.

Normally, when coating is performed using a vacuum deposition method such as ion blasting, the coating process is performed while the coating base material is heated to a predetermined temperature in order to improve the interlayer strength between the base material and the coating film. However, in the present ψJ, as shown in Figure 1, a heating-cooling cycle is applied to the coated base material during the coating process, the coating process is performed during the heating process, and the coating is repeated sequentially until the desired thickness is reached. With this treatment, it is possible to obtain a film thickness that cannot be achieved with conventional coating methods.In the treatment according to the present invention, as shown in FIG. It is a coating process, but from the second layer onwards, the coating material is coated with the same coating material, so the surface to be treated does not come into contact with the atmosphere, so the coating process is performed on an extremely clean surface, resulting in excellent adhesion. In Fig. 2, 2' indicates the second layer, and 2'' indicates the third layer.

The base material to which the method of the present invention can be applied is ore, steel material, A
l, A1 alloy, almost all other metals, AhOs,
There are ceramics such as SiO□ sic.

In addition, as a ceramic coating material, Ti
e, TiN, 811N4, SiC, A110g
Ni-N1p can be used as the cermet.

We-Co, Cu-CuO, etc. can be used, and as the metal, Al, Or, Ni, Ti, Fe, etc. can be used.

The method of the present invention will be specifically described below with reference to Examples.

Example 1 When tool steel (SKH9) was heated to 500°C and coated with TiN using the ion blating method, the maximum film thickness was about 10μ, and the coating treatment was carried out with the aim of increasing the film thickness further. When applied, peeling occurred. On the other hand, by applying the method of the present invention, the temperature of the tool steel is cycled 5 times from 500°C to 60°C according to the following procedure, and while the temperature is maintained at 500°C, TiN is coated to a thickness of 10 μm using an ion blating method. As a result of repeating the treatment three times, a coating of 36 μm was achieved without peeling on the treated surface fc.

i.e. 5 tm t x 30 wm x 50 m
A tool steel (8KH9) was used as a test piece, and the test piece was degreased by ultrasonic cleaning at 70 tons in the atmosphere, placed in a vacuum chamber, and evacuated to a pressure of 5 x 10-' Torr, and then exposed to Ar gas. was introduced and subjected to ion bombardment for 10 minutes under the conditions of a voltage of 750 V and a current of 1 A at a pressure of I X 10-'Torr.
After evacuation to the pressure of
is irradiated to heat and evaporate the Ti, and at the same time, N is added to the vacuum chamber.
After introducing t and maintaining the pressure f 8 X 10-'Torr, the shutter was opened and TiN't-
Coat 10 μm. Then close the shutter and
After stopping the coating, the heater was turned off and the temperature of the specimen was cooled to 50 °C, and after heating to 500 °C again,
An additional 10μ coating of TiN is applied under the same conditions as above. A total of six coatings were applied in the same manner to obtain a TiN coating with a thickness of 30 μm.

Example 2 A 5 mt x 30 m x 30 mm tool steel (SKH9) was subjected to the same degreasing and ion bombardment treatment as in Example 1, then evacuated to a pressure of 4 x 10'' Torr, and heated the test piece to 500 ° C. After irradiating the electron beam with an HCD gun at 47V and 450 people to evaporate the Ni and introduce air to maintain the pressure at 6 x 10”Torr, the shutter was opened and the Ni- in which NiO was dispersed in the Ni- Ni
0 The film was coated with a thickness of 10 μm. Next, coating was performed a total of three times in the same manner as in Example 1 to give a coating of 30
Ni-Ni0 coating of μ bait was obtained without peeling.

Example 3 When a carbon steel plate (3341) was heated to 400°C and coated with A1 by the ion blating method, the maximum limit film thickness was about 50μ, and the coating When the treatment was applied, peeling occurred.

On the other hand, applying the present invention, the temperature of the carbon steel plate was given two cycles of 400°C to 50°C according to the following procedure.
A1 was heated to 50 μm using the ion blating method while being held at 00°C.
As a result of repeating the thick coating process twice, a coating of 100 μm was achieved without peeling on the treated surface.

That is, 5 w t X 50 tm X 50 m
After degreasing and ion bombarding a carbon steel plate (SS41) in the same manner as in Example 1, 4X10-4T
The test piece was evacuated to a pressure of
μ-coated, cooled to 30℃, and then heated to 400℃ again.
After heating the A1 to a length of 50μ coating, total of 1
An A1 coating of 0.00 μm was obtained without peeling.

Example 4 Using a carbon steel plate (E3S41) of 5+at x 50 tm x 50 m, it was subjected to the same degreasing and ion bombardment treatment as in Example 1, and then exposed to an electrostatic gun using an electrostatic gun.
8KV.

Or was evaporated at 700 mA to obtain a film with a thickness of 60 μm. Next, heating and cooling were repeated in the same manner as in Example 1, and a 100 μm thick Cr coating was obtained by a total of 5 vapor depositions.

In the conventional method, peeling occurred when the bait was 30 μm or more, but in this example, no peeling occurred even when the bait was 100 μm or more.

As described above, the present invention is industrially valuable because it allows multilayer coating treatment to be performed without peeling off the coating material by a vacuum deposition method such as ion blasting.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a heating cycle of an object to be treated in the method of the present invention, and FIG. 2 is a diagram schematically showing a cross section of a coated surface obtained by the method of the present invention. Sub-agents 1) Meikoku Agent Ryo Hagiwara - Figure 1 ¥2

Claims (1)

[Claims] In a method of multi-layer coating p, ceramic, cermet, or metal on the surface of a workpiece using a vacuum deposition method such as ion blasting, the workpiece is heated to a certain temperature, the coating process is performed, and the coating material is coated. After coating to the peeling limit thickness determined by the coating conditions, the temperature of the object to be treated is cooled to room temperature, and then the temperature of the coated object is raised again to perform the coating treatment and peel. A multilayer coating method that is characterized by forming a film to a limit thickness, cooling it to room temperature, and repeating this process to form a film on the surface of the object to be treated.