JPH0472052A - Boride coated metallic material and boronizing treatment for metal surface - Google Patents

Abstract

PURPOSE:To obtain a material applicable to a member driving at high speed and requiring wear resistance by forming a boride coating on the surface of a metallic base material consisting of titanium, zirconium, or hafnium by means of vapor phase reaction. CONSTITUTION:A base material consisting of titanium, zirconium, hafnium, or alloy thereof is subjected to heat treatment in an atmosphere containing boron trichloride, by which a layer of the boride of the metal of the base material is formed on the surface of the above base material. By this method, the material applicable to a member driving at high speed and requiring wear resistance can be obtained.

Description

[Detailed Description of the Invention] [Summary] The present invention relates to a metal material coated with a boride and a method for boronizing a metal surface. , Ti, Zr, Hf, or an alloy thereof is heat treated in a mixed atmosphere of boron trichloride and an inert gas to coat it with boride.

[Industrial application field]

The present invention relates to a metal material coated with a boride and a method for boronizing a metal surface.

[Prior Art] In computers and computer peripheral devices such as external storage devices, various terminal devices related to input/output of information operate mechanically, so high-speed operation is required. There is an increasing demand for these various terminal devices to be smaller and lighter. Currently, in order to reduce the weight of various mechanical parts, Aβ
System materials are used. However, even with materials such as Aβ-3i alloy, which is one of the AI2-based materials, that have improved wear resistance by crystallizing primary St, primary St may fall off in parts that are driven at high speed, resulting in poor wear resistance. As aluminum alloys in general are soft and easily abraded by mating materials, heavy iron-based, copper-based, and bronze-based materials are still used for bearings that drive at high speeds. be. However, it is difficult to apply these materials to members that require both light weight and wear resistance.

[Problem to be solved by the invention]

Ti, Zr, and Hf are lightweight metal materials almost equivalent to Aβ, but conventionally there has been no excellent surface treatment technology for use in high-speed drive parts. - Since the film formed by anodic oxidation and thermal spraying, which are surface treatments for Ti, is porous, the film is easily chipped by high-speed sliding or impact.

Therefore, an object of the present invention is to provide a surface treatment method that can be applied to members that are driven at high speed and require wear resistance, and that can also be applied to pre-processed members and products with complex shapes.

[Means to solve the problem]

The above object, according to the present invention, provides Ti or a Ti alloy;
The surface of Zr or Zr alloy and Hf or Hf alloy is coated with boride (consisting of the base metal and boron), and since the boride metal is supplied from the base metal itself, there is a difference between the base metal and the base metal. The boride has very good adhesion (achieved by the material of the composition, strongly bonding and coating the surface).

The coating thickness is preferably in the range of 150 to 200 μm for components such as the head arm of a magnetic disk device.

Further, the method for boriding a metal surface according to the present invention uses boron monochloride as a boron source to coat the surface of a metal base material made of titanium, zirconium, or hafnium with boride through a gas phase reaction. It is characterized by the formation of

In the production of the above materials, the base metal Ti or Ti alloy, Zr or Zr alloy, or Hf or H
The f-alloy material is forged, rolled, extruded, and further machined if necessary to obtain a material, which is degreased and then coated. Boron trichloride is used as the boron source, and the concentration is 1300 to 1500 in a mixed atmosphere with an inert gas.
Heat treat at ℃. During this heat treatment process, the metal base material such as Ti and the boron of BCρ3 react to form a boride, which covers the metal surface and provides a wear-resistant material.

Subsequently, the boride coated surface is polished as necessary before use in products.

[Effect]

The material according to claim 1 is coated with a hard boride layer having a hardness of HvlO00 or more, and therefore has better wear resistance than Ag alone. The boride layer is formed by boronizing the base material itself, and has excellent adhesion to the base material, so it will not fall off during high speed driving.

In the method according to claim 2, the metal itself on the surface of the base material is borated by the gas phase reaction, so that the coating is dense.

〔Example〕

(1) A 10×10×5 mm pure Ti plate with a purity of 99.7% was used as a sample. Boring treatment is carried out at a temperature of 140°C in a mixed atmosphere of boron trichloride and argon at a volume ratio of 1=1.
The test was carried out at 0°C for 1 hour. After this treatment was completed, the cross section was observed under an optical microscope, and the thickness of the reaction layer was approximately 100 μm. In addition, when we investigated the hardness, we found that Ti is usually 130H.
According to the present invention, on the surface it is around 1100~
It was 1300Hv. Furthermore, X-ray diffraction of the reaction layer revealed that in addition to T i B x, T
A diffraction image of i was confirmed.

[Effects of the Invention] As explained above, according to the present invention, since the metal surface is coated with a hard boride with excellent adhesion, it has excellent wear resistance and can be applied to members driven at high speed. The material and its manufacturing method can be provided, which greatly contributes to the miniaturization and weight reduction of devices.

Claims (2)

[Claims] 1. A metal material characterized in that a boron compound layer of the base metal is formed on the surface of a base metal made of Ti, Zr, Hf, or an alloy thereof. 2. A metal surface boriding process characterized by forming a boride coating on the surface of a metal base material made of titanium, zirconium, or hafnium through a gas phase reaction using boron trichloride as a boron source. Method.