JPS5838218B2 - Method for forming a wire bomb spray layer on the sliding surface of a bearing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a wire explosive solvent layer on a bearing sliding surface in order to impart wear resistance, seizure resistance and conformability to the sliding surface of a bearing.

Conventionally, one of the methods to impart wear resistance, seizure resistance, and conformability to the sliding surfaces of bearings was the explosion method, in which metal wires such as molybdenum or carbon steel were melted and exploded with a large impact current. A method has been implemented in which the sliding surface of the bearing is coated in a layer by detonating an arbitrary metal thereon.

Wire blast melting is performed in layers, and molybdenum, tungsten, or 80% Ni-20% Cr is used as the base.

The reason for using molybdenum or tungsten as a base is
This is to improve the adhesion strength of the explosive layer to the bearing.

This adhesion is achieved by forming a diffusion layer between the base molybdenum and the base material, which provides strong strength. Peeling of the Bakura layer may occur between the second layers.

This is considered to be because a diffusion layer is not obtained between the layers, and moreover, 3 to 5 pores are present in the Bakumo layer, and the Bakumo layer is oxidized by these pores.

The photograph substituted for a drawing in FIG. 3 shows the state of peeling between the layers.

In Figure 4, which diagrams this, 1 is the bearing base material made of aluminum or aluminum alloy, 2 is the bomb layer, and 3 is the bearing base material made of aluminum or aluminum alloy.
is the first layer made of molybdenum, and the Bakura layer 2 is the shaded area 4 corresponding to the boundary with the second layer on the first layer 3.
Peeling is occurring.

This is clearly shown in the electronic analysis (EPME) analysis results shown in FIG.

That is, FIG. 5 shows the data obtained by applying electrons along the dashed line a in FIG. 4 and scanning in the direction of the arrow to search for metal elements, and the dotted line b in FIG. 2
The dotted line C indicates the boundary between the first layer and the second layer.

Molybdenum Mo exists between boundaries b and c,
Since no metal element is analyzed in the second and higher layers of the layer 2 from the boundary line C, it can be seen that there is separation between the first layer and the second layer.

In addition, since molybdenum Mo and aluminum At are precipitated at the same location at the boundary between the aluminum base material and the first molybdenum layer, there is a Mo-Al diffusion layer in that area, and the aluminum base material 1 is made of molybdenum. It is confirmed that there is no peeling of the first layer 3.

The object of the present invention is to prevent the above-mentioned separation of the first layer of the explosive layer and the second layer of arbitrary metal in the bearing sliding surface layer, and to improve the bearing characteristics.

According to this invention, when a plurality of blast layers are formed by wire blast dissection in layers on the sliding surface of a bearing, an easily soluble metal with a low melting point is placed between the first layer and the second layer. To provide a method for forming a wire blast layer on a bearing sliding surface, which comprises heating the wire blast layer at a temperature higher than the melting point of the self-fusing metal after a predetermined number of layers are blasted. It is something.

This increases the adhesion of the explosive layer, eliminates oxidation due to the porous layer between the first and second layers, and makes it possible to achieve densification. It is possible to maintain the unique porosity, maintain the oil retention property that is the original characteristic of wire bombs, prevent local and instantaneous heat generation during contact between solids on the sliding surface of the bearing, and improve seizure resistance and This improves conformability and abrasion resistance, and the lower layer, which does not require oil retention, is filled with porous material and made dense, making it possible to obtain strong adhesion.

Wear is often caused by adhesive wear due to direct contact between metals without any inclusions, but by improving oil retention,
By providing fluid lubrication or boundary lubrication between metals,
It is possible to prevent wear.

In addition, while increasing oil retention, the area and shearing force of metal-to-metal contact on the bearing surface can be reduced by bombarding a thin layer of soft metal elements on the highly hard intermediate layer, which do not cause metal-to-metal contact or welding to each other. In other words, since the abrasion force can be reduced, the coefficient of friction is improved and the boundary characteristics as a bearing are extremely good.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a process in which an explosive wire 6 inserted into the shaft hole of the bearing base material 5 is caused to explode onto the sliding surface of the bearing base material 5 by an explosive circuit consisting of a charger 7, a capacitor 8, and a switch 9. shows.

The above explosion is carried out in an inert gas or atmosphere, and the first layer of the explosion is made of molybdenum, tungsten or 8
0 modulus Ni-20 width Cr steel, from the second layer, wear-resistant metal wires such as carbon steel, molybdenum, tungsten, etc. are sequentially exploded in layers, but between the first and second layers In this method, self-fusing metals such as copper-nickel alloys having a lower melting point than the above-mentioned metal wires are exploded.

FIG. 2 shows a process of fitting the high frequency coil 10 to the bearing base material 5 after a predetermined number of layers has been detonated, and heating the explosive layer 11 formed on the sliding surface of the bearing base material 5.

This heating is performed at a temperature higher than the melting point (350'C) of the self-fusing metal.

The high frequency conditions for this are, for example, anode voltage of 9KV, anode current of 4A, and grid current of 0. 4 A, energizing time 1
I am satisfied with setting it to seconds.

According to a number of experimental results according to the above method, the Bakuman layer 11
The adhesion strength to the bearing base material 5 is 500
Those around Kt/cm2 are 900 to IOOOKP/c
It has been confirmed that m'i is improved.

This is because the self-fusing metal exploded between the first and second layers of the explosive layer 11 is melted and impregnated into the pores or porous parts between the first and second layers by high-frequency heating. This is because the gap between the first layer and the second layer is made denser.

Note that electric furnace heating, for example, can be used instead of the high-frequency heating, but the former is more suitable for mass production.

As described above, according to the present invention, it is possible to densify the blast layer, improve the adhesion strength to the bearing, and prevent peeling of the blast layer, and at the same time, the bearing sliding surface has properties unique to wire blasts. Since the bearing properties can be maintained as they are, it is possible to obtain extremely excellent bearing characteristics.

[Brief explanation of the drawing]

FIG. 1 is a process diagram of a bomb according to an embodiment of the present invention, and FIG.
The figure is a heating process diagram, Figure 3 is a micrograph showing a cross section of a conventional blast layer, Figure 4 is a schematic diagram of the micrograph in Figure 3, and Figure 5 is a line showing the results of EPMM+ analysis. It is a diagram. 5... Bearing base material, 6... Wire rod for explosives,
7... Charger, 8... Capacitor, 1
0...High frequency coil.

Claims (1)

[Scope of Claims] 1. When forming an explosive layer by performing wire blast melting in layers on the sliding surface of the bearing base material, a self-melting metal with a low melting point is interposed between the first layer and the second layer. 1. A method for forming a wire blast molten layer on a sliding surface of a bearing, the method comprising: blasting a predetermined number of layers, and then heating the blast layer at a temperature equal to or higher than the melting point of the self-fusing metal. 2 After forming the first layer of demolition on the sliding surface of the bearing base material by decomposing molybdenum, tungsten, or 80φNi-20%Cr steel, decomposing a self-fusing metal with a low melting point such as a copper-nickel alloy. Then, a hard metal such as martensitic structure is bombarded on top of it, and a thin layer of soft metal such as lead-based alloy, tin-based alloy, or copper-based alloy is wire-bombed on the sliding surface of the bearing. The radiation blast dissection layered method according to claim 1, which comprises forming a layer.