JP2002030363A - Wear resistant parts and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain wear resistant parts capable of withstanding use even in the severe environment of an high temperature-oxidizing atmosphere. SOLUTION: A metallic body, an alloy body or a sintered body having an almost columnar shape is formed of Ir, Rh or their alloy, next, this alloy or sintered body is melted while being rotated in an inert gas, and the molten metal drops scattered by centrifugal force are cooled and solidified into a spherical body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wear-resistant part typified by a ball of a ball bearing and the like, and more particularly to a wear-resistant part capable of withstanding use at high temperatures and in an oxidizing atmosphere, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, iron-based materials, brass and the like are mainly used for balls of ball bearings, which are wear-resistant parts. The reason is that the material is inexpensive and the processing is relatively easy. However, when these materials are used in an oxidizing atmosphere, corrosion progresses rapidly. Further, even a ball made of a stainless steel material which is hard to corrode could not be used because of high corrosion at high temperature.
Particularly in nuclear facilities, there are many environments in a high temperature and oxidizing atmosphere, and there is no preferable wear-resistant part that can be used even in such a severe environment.

[0003]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a wear-resistant part which can withstand use even in a severe environment such as a high temperature and an oxidizing atmosphere, and a method of manufacturing the same.

[0004]

According to the present invention, there is provided a wear-resistant component comprising a sphere made of Ir, Rh, Ru, or an alloy thereof.

[0005] The manufacturing method of the present invention for producing the above wear-resistant parts comprises producing a substantially cylindrical metal body, alloy body or sintered body from Ir, Rh, Ru or an alloy thereof, and then forming the metal body, alloy body or alloy body. The method is characterized in that a body or a sintered body is melted while rotating in an inert gas, and the molten metal scattered by centrifugal force is cooled and solidified to form a sphere.

[0006] In the above method for producing a wear-resistant part, the metal body, the alloy body or the sintered body is melted by disposing an electrode at a position facing the metal body, the alloy body or the sintered body. Alternatively, it is preferable that the sintered body be used as an anode and the electrode be used as a cathode and be melted by arc discharge.

[0007]

As described above, the wear-resistant parts of the present invention are Ir, R
h, Ru, or their alloys, they are very hard, and Ir, Rh, Ru, etc. are also excellent in chemical resistance. It can be used in the environment.

Further, the method for producing a wear-resistant part of the present invention as described above comprises Ir, Rh, Ru or an alloy thereof, which has been difficult to be processed into a sphere close to a true sphere by conventional machining. Since a substantially cylindrical metal body, alloy body or sintered body is melted while rotating in an inert gas, and the molten metal continuously scattered by centrifugal force is cooled and solidified to form a sphere, Ir, Rh, Ru or their alloy spheres can be easily and inexpensively mass-produced in a short time, and productivity is improved. In addition, since melting and cooling are performed in an inert gas, the oxidation of Ir, Rh, Ru, or an alloy thereof can be suppressed, and a clean and high-quality sphere can be manufactured. Furthermore, in the method for manufacturing a wear-resistant part of the present invention, the diameter (rotation radius) and the number of rotations of a substantially cylindrical metal body, alloy body or sintered body to be rotated are changed, so that the size of the sphere to be manufactured is changed. The diameter can be adjusted. The reason why the metal body, alloy body or sintered body to be rotated has a substantially columnar shape is to make the size of the manufactured sphere as uniform as possible.

Therefore, in the method for manufacturing a wear-resistant part of the present invention, the melting of the metal body, the alloy body or the sintered body is performed by using the metal body, the alloy body or the sintered body as an anode, and mounting the electrode opposed to the anode. Since the method in which the anode is used and melting is performed by arc discharge is employed, the apparatus configuration is simple, and the metal body, alloy body, or sintered body can be melted instantaneously, and the efficiency is high.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described.
First, 200 g of Ir was melted by an arc, then hot forged at 1300 ° C., and further 10 mm in diameter with a groove roll at 1300 ° C.
And cut into a length of 50 mm to obtain an Ir columnar body. Next, an Ir sphere was manufactured from the Ir cylinder using the rotating device 1 shown in FIG. That is, after attaching the Ir columnar body 3 to the tip of the spindle 2, a motor (not shown) is driven, and the spindle 2 is moved to 6000 through the drive belt 4.
Rotated at rpm. Then, the Ir cylinder 3 is used as an anode,
A voltage of 40 V was applied using the tungsten electrode 5 previously installed at a position facing the Ir cylinder 3 as a cathode to generate an arc discharge, thereby melting the Ir cylinder 3. The molten Ir droplet 6 is scattered by centrifugal force due to rotation, but is cooled and solidified by helium gas previously filled in the drum 7 and falls as a sphere. The Ir sphere 8 produced in this way is
Was collected from the lower collecting port 9 and classified, to obtain Ir spheres 8 having a particle size of 0.3 to 1.6 mm. The Ir spheres 8 have a smooth surface and a metallic luster in appearance, and when the surface is observed with an electron microscope, clear crystal grain boundaries are observed, so that Ir spheres 8 of good quality can be obtained. It was confirmed that. When the hardness of the Ir sphere 8 was measured, it was as high as about 300 HV. In addition, almost no corrosion was observed even when left in a high-temperature, oxidizing atmosphere for a long time.

[0011]

As can be understood from the above description, the wear-resistant part of the present invention is a sphere which is very hard and hard to corrode even in a high-temperature, oxidizing atmosphere. It becomes a wear-resistant part that can be used.

Further, the method for producing a wear-resistant part according to the present invention comprises:
Since the sphere is formed by the rotating electrode and the arc discharge in the inert gas, the above-mentioned excellent wear-resistant parts can be easily and inexpensively mass-produced in a short time, and the productivity is improved. Also, it is possible to obtain clean quality spherical wear-resistant parts,
In addition, by adjusting the size of the rotating electrode and the number of rotations, a spherical wear-resistant part having a required size can be easily obtained.

[Brief description of the drawings]

FIG. 1 is a schematic view of an apparatus for carrying out a method of manufacturing a wear-resistant part according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotating device 2 Spindle 3 Ir cylinder 4 Drive belt 5 Tungsten electrode 6 Ir drop 7 Drum 8 Ir sphere 9 Lower collection port

Claims (3)

[Claims] 1. A wear-resistant part comprising a sphere made of Ir, Rh, Ru or an alloy thereof. 2. A substantially cylindrical metal body, alloy body or sintered body is made of Ir, Rh, Ru or an alloy thereof, and then the metal body, alloy body or sintered body is rotated in an inert gas. A method for producing a wear-resistant part, wherein the molten metal is melted while being cooled, and the molten metal scattered by centrifugal force is cooled and solidified to form a sphere. 3. The method for manufacturing a wear-resistant part according to claim 2, wherein the metal body, the alloy body or the sintered body is melted by disposing an electrode at a position facing the metal body, the alloy body or the sintered body; A method for producing a wear-resistant part, wherein a metal body, an alloy body, or a sintered body is used as an anode and the electrode is used as a cathode and is melted by arc discharge.