JPS5861327A - Slide member excellent in wearproofness - Google Patents

Abstract

PURPOSE:To aim at improvement in wearproofness, by forming a flame sprayed layer composed of matter having a desired hole ratio on slide face between two members which touch and slide with each other, and being harder than these members. CONSTITUTION:A flame sprayed layer having a desired hole ratio on the surface of two members which touch and slide with each other and being harder than these members is formed up. For example, a flame sprayed film with a hole ratio of 25-40% is formed into a thickness of 0.1-5mm. with Ti and TiN or a mixture of these substances and then the hole part is impregnated with Pb, SN, Pb alloy, SN alloy, etc., as a soft substance. With this constitution, wearproofness for slide face is thus improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sliding mechanism in which two members slide into contact with each other, and more particularly to a sliding member in which a surface layer with excellent wear resistance is formed on the surface of the member.

In the development of wear-resistant materials, various alloys and surface treatment methods are being considered. One of them is the sintering method. One type of wear-resistant sintered body is an oil-impregnated sintered alloy in which the pores of the sintered body are impregnated with lubricating oil.

This sintered material is weak against high loads and mechanical shocks, and
Sintering of large objects requires a large press and is expensive. As a method for improving the brittleness of sintered materials, a method has also been proposed in which a sintered body is formed on the sliding portion of the surface of a highly tough material such as a steel plate. The problem with this method is that it is difficult to process products with complex shapes or cylindrical circumferences.

When two solid bodies are brought into contact and one slides against the other, friction occurs, causing surface damage where the surfaces of the two solids grind together. When two solids of different hardness are brought into contact and slid, the amount of wear on the one with higher hardness is much smaller than that on the one with lower hardness. If a lubricant such as a liquid or solid is inserted between two sliding bodies, the frictional force can be significantly reduced. The frictional force in this case is due to internal friction of the lubricant itself, and since the coefficient of friction is small and there is no contact between solids, no wear of the solids occurs. However, under high load or high-speed sliding, the lubricant inserted between the solids disappears partially or completely, and the solids come into contact with each other, increasing the frictional force and causing abnormal wear such as seizure. . Therefore, in order to prevent these problems, it is necessary for a lubricant to always be present on the contact surfaces, and the sliding member itself must have a lubricant retention effect or the presence of a substance with a low friction coefficient and excellent lubricating effect. The presence or absence will determine the quality of the sliding member. In order for the lubricant to stably exist on the friction surface,
It is preferable that the friction surface has a concave force. When the sliding member itself has pores, the pores appear on the friction surface and act as a lubricant retainer. As mentioned above, the harder the material, the less wear it will cause, so if there are hard and soft parts in the same part, the soft part will wear more than the hard part, and the soft part will become a recess where the lubricant will be retained. be done. A sliding member in which the same sliding surface consists of a soft part and a hard part has good wear resistance. It is believed that a material having recesses formed on the sliding surface as described above can provide superior wear resistance than a material having no recesses.

In view of the above-mentioned wear phenomenon and lubrication effect, the present invention has a sliding surface composed of a hard part and a soft part, and further has a surface layer having recesses.

An object of the present invention is to provide a sliding member with excellent wear resistance.

The present invention is characterized in that a sprayed layer made of a hard material having a desired porosity and harder than the member is formed on the surface of the sliding member, which is subjected to friction when the members come into contact with each other.

Furthermore, the present invention has a desired porosity on the surface of the sliding member,
It is characterized in that a thin layer is formed of a thermally sprayed layer made of a hard material that is harder than the member, and a soft material that is softer than the material of the thermally sprayed layer and impregnated into the pores of the thermally sprayed layer.

The sprayed layer is preferably a porous sprayed coating of Ti, TiN, or a mixture of Ti and TiN, and the pores of this sprayed layer are filled with at least one of low melting point metals such as PB+8", PB gold alloy, and Sn alloy as a soft substance. Alternatively, it is preferable to impregnate with resin, especially Ti.

TiN is light and has the characteristic that pores are easily formed by thermal spraying.

The thermal spray coating of the present invention has pores uniformly distributed. The pores in this sprayed layer need to be continuous to some extent when impregnating a soft material. If there are only isolated pores, the sprayed layer cannot be impregnated in the depth direction, and only the pores that appear on the surface will be impregnated, and they will be easily removed by finishing processing or initial wear. There is a risk of

Therefore, the pores must be continuous to some extent in the depth direction. As described above, the isolated pores are present on the sliding surface, have a lubricant retention function, and serve to further improve the sliding characteristics.

The porosity of these pores in the sprayed layer is preferably 10 to 50% by volume. If it exceeds 50, the strength of the thermally sprayed coating will decrease, and there is a risk that the coating will be deformed due to high loads.

The porosity can be set to a desired value by controlling the thermal spraying conditions. In particular, a ratio of about 25 to 40 is preferable.

The thickness of the as-sprayed thermally sprayed layer is preferably 0.01 to 5 mm. In order to form homogeneous pores, it is preferably 0.01 or more, and in order to prevent peeling from the base material and to improve the impregnation in the depth direction, it is preferably 5 or less.

After forming the thermal sprayed layer with pores as described above, an impregnation treatment is performed as necessary. For example, it is inserted into a vacuum container, the inside of the cavity is sufficiently evacuated so that the pressure becomes less than 10"l'orl", and the material is immersed in the liquid of the impregnated material.

If the impregnation is insufficient by dipping alone, pressure impregnation is carried out by applying a pressure of 3 to 7 Ky/cm2. After sufficient impregnation,
It is taken out from the vacuum container and finished by machining, etc. The thickness of the sprayed layer after finishing varies depending on the conditions of use, but is preferably about 0.002 mm to 4.5 mm. If it is less than 0.00211 on, there is a risk that the base material will be exposed due to initial wear etc., and if it is more than 4.5 on, there is a risk that peeling from the base material will occur during use.

In addition, when the coating layer is thick, the properties of the sliding surface are determined only by the properties of the coating layer, and the excellent properties of the base material that appear on the surface of the sliding part through the coating layer, such as strength and hardness, are determined only by the properties of the coating layer. There are problems such as unusability and deformation of the coating layer due to high loads. Therefore, it is particularly preferable that the thickness be 0.01 mm to 0.8 mm to withstand high loads by utilizing the properties of the base material.

The sliding member of the present invention made by the method described above can retain lubricant by the pores, and in particular, Pb is added to the hard sprayed layer of Tr and TiN having the desired porosity.

It has a sliding surface made of a mixture of f3n and soft materials such as alloys or resins thereof, and has excellent wear resistance due to the synergistic effect of the lubricating oil retention effect of isolated pores.

The present invention allows mass-producible sliding members to be formed regardless of the shape or size of the member.

Example 1 A JIS-8841 steel bar was used as the base material, and plasting was carried out with a grid of ≠120 and a pressure of 4 Kg 7 cm 2 to improve the adhesion of the coating layer to the end face to be thermally sprayed. This plasticized end face has a grain size of 2.
A Ti powder having a thickness of 0 μm to 40 μm was sprayed using sialbone gas plasma using a plasma spraying device to form a sprayed coating of Ti with a weight of about 1.0 W.

As a result of observing the cross section of the sprayed layer with a microscope, it was found that the sprayed layer had continuous pores from the surface to the inside and fine isolated pores inside, and the porosity was about 40% by volume. Ta.

Next, these samples were inserted into a graphite crucible in a heatable vacuum vessel together with PB and evacuated to below 10-2']'Orr. After sufficient evacuation, the graphite crucible was heated to make PB into a 55 Or melt, and the sample was immersed in this melt and impregnated by applying a pressure of about '5 Ky 7 cm 2 . After machining the surface of this material, the surface was analyzed for Pb using a scanning electron microscope, and as a result, it was found that the pores were impregnated with Pb. Furthermore, PB had penetrated into the interior of the country.

(a) To evaluate the wear resistance of the thus obtained coating layer, the coating layer was machined to a thickness of 0.5 ttan.

The test was conducted using a rotary abrasion tester as shown in FIG. The mating material is JIS standard F'CMP60 (Rockwell hardness: C scale 60). Friction speed: 10m/
Second, load: 100K910n'', lubricant: turbine oil≠120.

FIG. 2 shows the relationship between the amount of wear and time, and the conventional material used was an oil-impregnated sintered alloy of 70 wt% Fe-30 wt qbCU. As shown in the figure, it can be seen that the Ti sprayed coating of the present invention impregnated with PB has good wear resistance and can withstand long-term use.

Example 2 J, IS-853C steel bar was used as the base material. Plasting was applied to the outer peripheral surface of the steel bar under the same conditions as in Example 1, and the same particles as in Example 1 were applied with N2 plasma using a plasma spraying device. A thermally sprayed coating of TiN was formed to a thickness of 0.8 mm using Ti powder having a diameter of 0.8 mm. The porosity of this thermal sprayed layer was about 40 parts by volume. After this sample was impregnated with Bn under the same conditions as in Example 1, the coating layer was finished by machining to a thickness of 0.3 m, and an abrasion test was performed using an Okoshi type abrasion tester. The test conditions are: mating material: JIS standard SCM3 (Rockwell hardness: C scale 60), friction speed: 3 m/
seconds, wear distance: 200m, load: 12.6Kg.

Lubricating oil: Turbine oil≠120.

FIG. 3 is a diagram showing the relationship between friction speed and wear loss. As the conventional material, the same li'e-Cu oil-impregnated sintered alloy as in Example 1 was used. As is clear from the figure, the Ti of the present invention
It can be seen that the N sprayed layer impregnated with Sn has extremely excellent wear resistance.

Example 3 J'lS-845C material was used as the base material, and the same Ti powder as in Example 1 was sprayed with plasma mixed with argon gas and nitrogen gas using a plasma spraying device to form sprayed layers of T1 and TIN. formed. The porosity of this material was approximately 40 parts by volume. This sample was placed in a vacuum container together with the liquid resin, and after the vacuum was evacuated to below 10-2'J'orr, the sample was immersed in the resin and impregnated by applying a pressure of about 7 Kg/cm2. . These samples were subjected to a rotary wear test in the same manner as in Example 1. Test conditions are friction speed: 8m/sec, load: 50Kq/lyn", lubricating oil: turbine oil + 120.Test time + 5oh, mating material: J TS-8
UJ2 (Rockwell hardness: C scale 60).

FIG. 4 shows the relationship between the amount of wear and load. As is clear from the figure, it can be seen that the thermal sprayed layer of the present invention in which Tj and TiN are mixed and impregnated with resin has good wear resistance.

As described above, the sliding member of the present invention has significantly excellent wear resistance.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of a rotary abrasion tester used to evaluate wear resistance, Figure 2 is a graph showing the relationship between the amount of wear and time for the inventive material and conventional material in the rotary abrasion test, and Figure 3 FIG. 4 is a graph showing the wear loss and friction speed of the present invention material and the conventional material as determined by the Okoshi type wear test, and FIG. 4 is a graph showing the relationship between the wear amount and load of the present invention material and the conventional material as determined by the rotational wear test. 1... Test piece, 2... Compatible material, 3... Test piece fixing jig. Figure 1 Figure 2 Closed () 1 Figure 3 Hayabusa Figure Load (Nishi Am2)

Claims (1)

[Scope of Claims] 1.2 At least one sliding surface of the members on which the members slide in contact with each other has a desired porosity. A sliding member with excellent wear resistance, characterized in that a sprayed layer made of a hard material harder than the above-mentioned member is formed. 2. The sliding member with excellent wear resistance according to claim 1, wherein the sprayed layer is made of at least one of titanium and titanium nitride. 3. The sliding member with excellent wear resistance according to claim 1 or 2, wherein the porosity is 10 to 50 volume fraction of the thermal sprayed layer. 4.2 The sliding surface of at least one of the members on which the members slide in contact with each other is coated with a sprayed layer made of a hard material having a desired porosity and harder than the member, and the pores thereof are impregnated. A sliding member with excellent wear resistance, characterized by the formation of a thin layer of a substance that has a lubricating effect. 5. The substance having a lubricating effect is tin or a tin alloy. 5. The sliding member with excellent wear resistance according to claim 4, which is made of at least one of lead and a lead alloy, or a resin. 6. The sprayed layer is made of at least one of titanium and titanium nitride.
A sliding member with excellent wear resistance according to claim 4 or 5, comprising: 7. The sliding member with excellent wear resistance according to any one of claims 4 to 6, wherein the substance having a lubricating effect has a volume fraction of 5 to 45 of the thin layer.