JPS602697A - Formation of wear resistant coated layer - Google Patents

Abstract

PURPOSE:To form a wear resistant homogeneous coated layer in a high product yield by forming a composite plated film contg. deposited hard particles with a high m.p. on the surface of a metallic substrate and by melting the film and the surface layer of the substrate by heating. CONSTITUTION:A composite plated film 2 contg. deposited hard particles with a high m.p. is formed on the surface of a metallic substrate 1 of oxygen-free copper or the like using a plating bath prepd. by dispersing alumina particles or the like in a nickel plating bath. The film 2 and the surface layer of the substrate 1 are melted by heating 4 with laser light 5 or electron beams to form a wear resistant coated layer 3 on the outside of the substrate 1. By this method the coated layer with superior wear resistance can be simply formed.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a method for forming a coating layer with excellent wear resistance, and more specifically, the present invention relates to a method for forming a coating layer with excellent wear resistance, and more specifically, when formed on the surface of a base material such as a sliding part, the coating layer lasts for a long period of time. The present invention relates to a method for forming a coating layer that exhibits excellent wear resistance.

[Technical background of the invention and its problems]

In various electronic parts, machines, mechanisms, etc., there are many components that are forced to slide or come into contact with each other due to the structure of their operation, and the metal surfaces that make up these components naturally have a high degree of wear resistance. It is required to have gender.

In order to meet these demands, methods for forming a coating layer with high hardness and excellent wear resistance on the surface of the base material include:
There are thermal spraying methods, thermal spray welding methods, and sintering methods, but none with sufficiently satisfactory performance has yet been obtained. In other words, the thermal spraying method requires steps such as sandblasting the surface to be treated and spraying and welding wear-resistant metal powder by thermal spraying, which not only takes a long time, but also tends to cause pores in the coated metal layer, resulting in a low yield. There was a drawback. The thermal spray welding method uses a self-fluxing alloy and sprays the metal powder in one welding process, so it has extremely low processing efficiency and also tends to create pores in the coated metal, resulting in a low yield (80cm at most). there were. In the sintering method, wear-resistant metal powder is applied onto the base material, then sintered in a vacuum or inert atmosphere, and simultaneously bonded to the surface of the base material. There were disadvantages in that pores remained and it was difficult to make the thickness of the sintered layer uniform.

[Purpose of the invention]

The present invention addresses the above-mentioned problems and aims to provide a method for forming a homogeneous wear-resistant coating layer with a high product yield.

[Summary of the invention]

The method of the present invention uses a metal plating bath in which particles with high hardness and high melting point are dispersed to obtain a composite plating film in which particles with high hardness and high melting point are eutectoided with the metal for plating on the surface of a metal substrate. and a second step of melting and heating the composite plating film and the metal base material to obtain an alloy layer of the composite plating film and the metal base material with a uniform thickness in which high hardness O high melting point particles are uniformly dispersed. It is characterized by: The invention will be explained in more detail below.

The high hardness/high melting point particles used in the first step of the present invention are preferably oxides, carbides, nitrides, borides, etc., or a combination thereof, and preferably have a particle size of 10 μm or less. More preferably, the island size is 1 to 5 μm. The particle size affects the abrasion resistance of the coating that is formed, and as the particle size increases, the abrasion resistance improves and the amount of wear decreases, but the damage and amount of wear to the mating material of sliding parts or contact parts increases. Become.

The metal plating film formed by eutectoid together with high hardness and high melting point particles can be applied to any film as long as the internal stress of the film is small and the film formation rate is fast to a certain extent.For example, Ni, Or, Co, Ou, Fe.

Al, Au, Pb, Zn, N1-P, alloys thereof, etc. will not impair the effects of the present invention. Further, the layer formed on the surface of the base material does not necessarily have to be a single layer, and may be a laminated film layer having different compositions.

The amount of high hardness/high melting point particles contained in the metal plating film is 1% by weight based on the total coating in order to obtain good wear resistance.
It is preferably 2.5 to 4 or more, more preferably 2.5 to 4.
．． It is 0% by weight. The method of forming a film with excellent wear resistance of the present invention includes dispersing the high hardness and high melting point particles in a plating bath that provides the metal plating film described above, immersing the base material in the plating bath, and subjecting the base material to the metal plating film under predetermined conditions. High hardness and high melting point particles are co-deposited with the plating metal on the surface. At this time, it is added to the plating bath. The amount of the high hardness/high melting point particles is preferably 50 to 300 da/l, more preferably 100 to 200 y/l, relative to the plating bath. If the amount of high hardness O high melting point particles added is less than 50y/l, it will be difficult to obtain a coating with excellent wear resistance;
If the amount exceeds 100%, the wear resistance will not improve in proportion to the amount added, and the plating conditions may be adversely affected.

The plating conditions may be such that high hardness and high melting point particles can be eutectoid in each plating bath, for example, a current density of 5 to 3.
0A/dze, plating solution flow rate 0.5-2. ORI/Sec
, the bath temperature is preferably about 40 to 70°C.

Under such conditions, if the flow rate of the plating bath is increased by vigorously stirring the plating bath, for example, the formation rate of the plating film will increase, but the amount of eutectoid of high hardness Q high melting point particles will decrease, so the plating bath will It is preferable to appropriately select the flow rate and the like.

In the second step of the present invention, the heating and melting treatment of melting and heating the surface portion of the metal base material and the plating film in which the high-hardness O high-melting point particles eutectoided in the first step has an energy density of 1.
Any device with an output of ×1011 W/aIL or higher can be used, but laser beams and electron beams are recommended because they can easily obtain the necessary energy density and take into consideration shortening of processing time and work efficiency. It is preferable to use

If the energy density is high, the surface of the irradiated material can be rapidly heated and cooled by shortening the irradiation time, and the heat-affected zone can be made extremely small. Furthermore, the thickness of the molten layer is uniform and any thickness can be obtained. The energy density used can be selected in various ways depending on the thickness of the alloy layer to be formed, and examples include conditions such as lXl0' to 10' w/c+4 and irradiation time of about 10-1 to 10'' sec. It will be done.

The atmosphere during this heat treatment is vacuum (preferably 10
'Torr or less) or an inert atmosphere (e.g. argon,
Helium, etc.) is preferred. When irradiating the surface of the composite plating film with a laser beam or electron beam, either move the laser beam or electron beam to sequentially move the irradiated area so that melting and heating are performed uniformly on the heat-treated surface, or
It is necessary to move the divinely processed metal body.

〔Effect of the invention〕

According to the method of the present invention, the thickness of the coating layer can be arbitrarily and accurately controlled, and an alloy layer of a plated metal and a metal base material in which high hardness/high melting point particles are uniformly dispersed can be obtained. Wear resistance is improved by dispersing and alloying particles with high hardness and high melting point, and excellent wear resistance is exhibited over a long period of time. Furthermore, by selecting the composition of the metal base material or the plating metal, it is possible to improve the corrosion resistance. Further, the forming method of the present invention allows a coating having excellent wear resistance to be easily formed.

[Embodiments of the invention]

The method of the present invention will be explained in more detail below using examples and drawings.

Example 1 As the metal base material (1), oxygen-free steel (JIS-01011BB
), and a Ni composite plating film (2) on which alumina particles with an average flow diameter of 1 μm were eutectoid was applied on the outer peripheral surface. In the plating method, a plating bath having the following composition was prepared by dispersing alumina particles having an average particle size/μ distribution in a nickel plating bath.

Alumina particles 200 f//1 Using the above plating bath, using oxygen-free copper as a cathode and electrolytic nickel material placed opposite the plate as an anode, plating was performed under the following plating conditions to form an oxygen-free copper surface. A composite plating layer of about 80 pts thick made of nickel-alumina particles was formed on the surface.

Electrolytic conditions were set to a current density of 20 A/dm'. At the same time, a comparative material was obtained in which a plating layer was formed using the same procedure except that a plating bath containing no alumina particles was used in the above treatment.

For the above composite plating materials and comparative materials, a laser beam (5) was applied to the surface of the plating layer in an Ar atmosphere at an energy density of I
X 10' w/d 1 scanning speed 10mm/sec
(Rotating the material to be treated) to melt and heat the plated layer and the surface layer of the base material +4)l, to form an alloy layer on the outer peripheral surface.

When we observed the cross-sectional metallographic structure of the base material obtained through the above treatment, we found that the alloy layer was about 200p%±2 from the outer surface.
The thickness was approximately uniform. It was confirmed that alumina particles were also almost uniformly dispersed in the composite plating material.

For each test piece obtained by the above treatment, a wear test was conducted using an Amsler type wear tester in the presence of lubricating oil under the conditions shown below. The results are shown in Table 1.

Test conditions Table 1 Example 2 As a metal base material, the outer diameter is 40 mm, the inner diameter is 16 mm, and the thickness is 10 mm.
The plating method involves using a polished steel bar (JIS 8GDI) with a diameter of 1.5 mm and applying an Or composite plating film on the outer circumferential surface of the steel bar with an average grain size/μ of TiN particles eutectoid in a chromic acid-sulfuric acid bath. A plating bath having the following composition in which TiN particles having islands were dispersed was prepared.

Using the above plating bath, the surface of the polished steel bar was plated with the following plating conditions using the polished steel bar as a cathode and the lead alloy material placed opposite it as an anode.
- A composite plating layer with a thickness of approximately 70 microns was formed consisting of TiN particles.

At the same time as the electrolytic conditions, a comparative material was obtained in which a plating layer was formed using the same procedure as above except that a plating bath containing no TiN particles was used in the above treatment.

For the above composite plating materials and comparative materials, an electron beam was applied to the surface of the plating layer in a vacuum of 2X' Torr at an energy density of 2 X 10' w/d s and a scanning speed of 25 u/s.
ec (rotating the material to be treated) to melt and heat the plated layer and the surface of the base material to form an alloy layer on the outer peripheral surface.

When we observed the cross-sectional metallographic structure of the base material obtained through the above treatment, we found that the alloy layer extends approximately 400 μm from the outer surface.
30 and had a substantially uniform thickness. As a result, the Or concentration is approximately 17%, resulting in a medium-Or ferritic stainless steel composition, which is expected to improve corrosion resistance. It was confirmed that TiN particles were also almost uniformly dispersed in the composite plating material.

Each test piece obtained by the above treatment was subjected to a sliding wear test using an Amsler type wear tester in the presence of lubricating oil under the conditions shown below. The results are shown in Table 2.

Test Conditions Table 2 As is clear from the results shown above, the surface treatment method of the present invention produces an alloy in which high-hardness, high-melting-point particles with excellent wear resistance are uniformly dispersed and has a uniform thickness. It was confirmed that the layer could be applied by a relatively simple operation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view illustrating the method of the present invention. +11... Metal base material, (2)... Coating (composite plating layer), (3)... Wear-resistant coating layer, (4)... Melting heating area, (5)... Laser light . Agent Patent attorney Kensuke Chika (and 1 other person) Figure 1

Claims (1)

[Claims] (1) High hardness Q along with plating metal on the surface of the metal base material
A first step of forming a film in which high melting point particles are eutectoid;
A method for forming a wear-resistant coating layer, comprising a second step of melting and heating the coating and the metal substrate surface layer. (2. A method for forming a wear-resistant coating layer according to claim 1, characterized in that the second step is melting and heating with a laser beam or an electron beam.