JPS61166962A - Sliding contact member having excellent wear resistance and its production - Google Patents

Abstract

PURPOSE:To obtain efficiently a sliding contact member having high oil holding power and excellent wear resistance by forming recesses by photoetching to a metallic member having a sliding contact surface then spraying thermally a thermal spraying material thereto in the state having a resist film remaining thereon and removing the above-mentioned film and the thermally sprayed layer on the film. CONSTITUTION:A plating layer 2 of hard Cr, etc., is formed on the surface of a base material consisting of an alloy cast iron, etc., and thereafter the surface is formed to a smooth sliding contact surface 2a. The oil holding recesses 2b are formed on such surface by photoetching of the conventional practice. Thermal spraying particles such as Mo are projected from a plasma spraying nozzle 5 to the resist film 4 for photoetching and recesses 2b to laminate the thermal spraying particles in the recesses 2b without removing the film 4 remaining on the sliding contact surface 2a. The film 4 and the sprayed layer 3a on the film 4 are removed and the sliding contact member formed with the porous sprayed layer 3 of Mo, etc., having the lubricating oil holding function only in the recesses 2b is obtd.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention is directed to improving the wear resistance of sliding contact members used, for example, in engine cylinder liners, and to improving the wear resistance of sliding contact members with excellent wear resistance. It relates to an efficient manufacturing method.

[Prior art]

Conventionally, in an engine, a piston slides inside a cylinder block, but a cylinder liner is fixed inside this cylinder block as a sliding contact member having a sliding surface that makes contact with the piston. The liner must have high abrasion resistance. To improve this wear resistance, i! ! ! Quantity? 'Ii lubricating oil may be retained, and this retained lubricating oil enhances the lubrication effect and improves wear resistance. And the above W
II. In order to retain the lubricating oil on the sliding surface, there is a method of forming an oil retaining recess for retaining the lubricating oil on the sliding surface.

By the way, the oil retention function of the oil retention recess mentioned above is as follows.
The larger the area ratio of the recesses, that is, the value obtained by dividing the total opening area of all the oil holding recesses by the area of the entire sliding surface, the larger the area ratio becomes. , the area of the part of the plate that makes sliding contact with the piston under high pressure becomes smaller, which increases the surface pressure per unit surface area, which is undesirable from the viewpoint of improving wear resistance.On the other hand, without increasing the area ratio too much, In order to increase the oil holding capacity, it is possible to increase the depth of the oil holding recess, but in the conventional method of forming the oil holding recess by applying reverse electric treatment to the hard plating layer, the recess is If the amount of reverse electrolysis is increased in order to increase the depth, a problem arises in that electrolysis is promoted even in a portion of the plateau between the recesses, resulting in worsening of the surface roughness.

Therefore, the applicant of the present application has filed an application for a sliding contact member in which deep oil retaining recesses are regularly formed on the sliding contact surface using a photo-etching method as a sliding contact member that can solve the above-mentioned conventional problems. 58-111200), according to this prior art, a deep oil holding recess can be formed without deteriorating the surface roughness of the part of the plate, and the oil holding capacity can be improved without significantly increasing the area ratio. can improve wear resistance.

By the way, since the lubricating oil that is supplied and held in the oil holding recess is simply accumulated in this recess, it tends to be dragged away by the piston as it slides. In particular, as the sliding speed of the piston increases, the amount carried away increases. Therefore, even in the case where the deep oil retaining recess is formed, depending on the sliding speed, the oil retaining ability may be insufficient.

[Purpose of the invention]

Therefore, the object of the first invention of the present application is to provide a sliding contact member that has a high oil retention ability that provides sufficient lubrication even at high sliding speeds, and that can greatly improve wear resistance. A second object of the present invention is to provide a method for manufacturing a sliding contact member that can efficiently obtain the above-mentioned sliding contact member having a high oil holding capacity through a simple process.

[Structure of the invention]

The first invention of the present application is a sliding contact member in which a hard plating layer is formed on a base plate of a metal plate, a large number of recesses are formed in this plating layer, and a porous sprayed layer is provided in the recesses. Therefore, in this first invention, the lubricating oil does not simply accumulate in the recess as in the conventional case (,
The /12I? The FK oil is not carried away by members sliding on the sliding contact surface, and furthermore, by utilizing the characteristics of the sprayed layer itself, it contributes to improving wear resistance.

As a method for forming a recess in the hard plating layer, for example, a chromium plating layer, and forming a porous sprayed layer of molybdenum, for example, which has a lubricating oil retaining function in the recess, as described above, the recess is formed by photo-etching. Since a method for forming a oxide film is known, and it is also known that a thermally sprayed layer of Mo or the like has excellent scuffing resistance, the following method can be considered. That is, the method involves etching recesses in the Cr plating layer by photoetching, removing the photoetching resist film, and then plasma spraying MO onto the plating layer, for example. However, a treatment method simply combining the photoetching method and plasma spraying may cause the following problems.

■ There is a strong oxide film on the Cr plating layer,
In addition, since the Cr plating layer has poor wettability with respect to sprayed particles, the sprayed particles do not adhere to the surface of this plating layer but scatter around. As a result, the sprayed particles inhibit the spraying into the recesses, and It becomes difficult to form a sprayed layer inside the surface.

■ Also, in the case of thermal spraying to the above-mentioned recesses, as mentioned above,
Thermal spray particles also collide on the R plating layer, but these colliding particles cause surface roughness of the Cr plating layer itself.
In the end, wear resistance cannot be improved that much. □ Therefore, the second invention of the present application is a method for manufacturing a sliding contact member with excellent wear resistance, in which a metal member consisting of the hard plating layer having a sliding contact surface and a metal base material is subjected to a photoetching method. After forming a large number of concave portions, a thermal spraying material is thermally sprayed while the photoetching film remains on the metal member, and then the resist film and the thermal sprayed layer formed on the resist film are thermally sprayed. As a result, in the method of the present invention, since the resist film remaining on the metal member is soft,
Thermal spray particles easily adhere to this resist film, so the sliding surface of the gold-N member will not be roughened by the spray particles, and the spray particles will not scatter to the metal member, so this scattering will not occur. The particles do not prevent the thermal spray particles from entering the recesses. Moreover, unnecessary thermal sprayed layers on the resist film can be easily removed by removing the resist film.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a sliding contact member according to an embodiment of the first invention of the present application,
For example, the inner surface of the cylinder liner is shown, and in the figure,
3 is a base material made of gold paint, for example alloy cast iron, and a hard plating layer, for example a Cr plating layer 2, is formed on the surface of this base material 1. It is a sliding surface 2a that comes into sliding contact with a piston, which is a moving member.The sliding surface 2a of this Cr plated layer 2 has a
A large number of oil holding recesses 2b are formed vertically and horizontally in a pinch manner over the entire surface of the sliding contact surface 2a by photo-etching, and each oil holding recess 2b has a substantially U-shaped longitudinal section with a circular opening in plan view. This sliding surface 2a
The portion where the recessed portion 2b is not formed is a part of the plate that comes into contact with the piston.

A sprayed layer 3 formed by plasma spraying Mo, for example, is formed in each of the oil retaining recesses 2b, and its outer surface is substantially flush with the sliding surface 2a.
Further, since the sprayed layer 3 is porous, it has the function of reliably retaining lubricating oil.

In the sliding contact member of this embodiment, the oil holding recess 2b
Since the sprayed layer 3 in ) is porous, the lubricating oil is reliably retained within the sprayed layer 3 even when the sliding speed of the sliding member, in this case the piston, increases. The effect can be obtained over a long period of time, and since the characteristics of the thermal sprayed layer 3 itself can be utilized, the wear resistance can be greatly improved.

Furthermore, as mentioned above, the spray particles sprayed on the flat part of the Cr plating layer 2 are scattered around and are difficult to adhere to the flat part. Since the sprayed layer is formed on the surface of the sprayed layer 3, the sprayed particles do not scatter and easily and reliably adhere to the inner surface of the oil holding recess 2b.
It can improve the adhesion with.

Next, a test for confirming the effect of improving the wear resistance of the sliding member of the above example will be described. In this test, the degree of damage and seizure resistance of the sliding contact surface is tested, and the wear resistance is evaluated based on this.

FIG. 2 shows a rotary abrasion tester for testing the abrasion resistance of the above-mentioned examples by a pin-disc abrasion test method. In the figure, 11 is a disk rotating section, and a disk rotating shaft 12 is connected to a motor (not shown) of this section.
A disk 13, which is a test piece, is attached to this rotating shaft 12, so that the disk 13 is rotated at a predetermined rotational speed. Reference numeral 14 denotes a disk pressing section, and a support arm 15a is swingably attached to the support member 15. A pin 16 for sliding on the sliding surface of the disk 13 is attached to the tip of the support arm 15a, and a pin 16 is attached to the rear end of the support arm 15a. A hanging rope 17 is connected to the guide pulley 1.
8, and a load 19 is suspended from the lower end of the pin 16, so that the pin 16 is pressed against the sliding surface of the disk 13 by the pressing cylinder MP.

Here, the base material of the disk 13 is made of alloyed cast iron, and the surface thereof has a hard Cr plating layer (thickness: 50 μm).

Vickers hardness 900-1000), then #
It has been given a 1000 honing finish.

In the test piece of this example, an oil retaining recess was formed in the disk 13 by photoetching, and a molybdenum sprayed layer (about 20 μm in thickness) was formed in the recess. In Comparative Example 2, the disk 13 described above was used as is. The pin 16 is a flat rectangular plate made by chilling alloyed cast iron having the chemical components shown in Table 1, and its sliding surface with the disk 13 is subjected to the following machining force. ing.

A. Polished whetstone: GC#60 Abrasion: 1.6a B. Shot-blast finished Shoto 2 carborundum #20 Abrasion: 10-40μ This test examines the effect of improving wear resistance not due to lubricating oil but due to the sprayed layer formed in the oil holding recess.

■, Test conditions Pressure load: P = 4.5Kg Disc circumferential speed: 5 m/s6 (Test time = 10 minutes Lubrication conditions: No lubrication ■, Test results Table 2 As is clear from the test results (Table 2 above) In Comparative Example 2, in which only a chromium plating layer was formed on the base material, the degree of damage to the surface of the disk 13 was large, and the amount of wear on the pin 16 was large; In Comparative Example 1, the degree of damage to the surface of the disk 13,
Both the amount of wear on the bottle 16 is significantly reduced, and in this example, a molybdenum sprayed layer is further formed in the recessed portion.
The degree of damage to the surface of the disk 13 has become even smaller.
Further, the amount of wear on the bottle 16 is reduced to about 1/2 of that in Comparative Example 1, and it can be seen that the wear resistance is increased (improved) due to the molybdenum sprayed layer itself.

Next, the seizure resistance test will be explained. This test tests the effect of improving the oil retention function by the molybdenum sprayed layer formed in the oil retention recess.

■, Test conditions Pressure load: P = 4.5Kg Disc circumferential speed: 5m/sec Lubrication conditions Nioil (10W40) and kerosene 1:9
Drop lcc of lubricating oil mixed at (Vol ratio).

■Test Results Table 3 As is clear from the test results (Table 3), the test piece of this example took a longer time to seize than Comparative Example 1, and this indicates that the molybdenum sprayed layer It can be seen that the oil retention function has improved.

FIG. 3 shows a process diagram of a method for manufacturing a sliding contact member according to an embodiment of the second invention of the present application, and the method of this embodiment mainly involves forming oil retaining recesses by photoetching and forming a thermal spray layer by plasma spraying. It consists of two stages.

(I) First, a hard chromium plating layer 2 is formed on the surface of a base material 1 made of alloyed cast iron, and the surface of the plating layer 2 is smoothed by polishing or honing to form a sliding contact surface 2a.

(II) Next, after coating the sliding contact surface 2a, the sliding contact surface 2a is coated with an ultraviolet-sensitive photoresist, and a photomask prepared in advance on the photoresist film 4 (
(not shown) are placed in close contact with each other. This photomask is a film-like product obtained by creating an enlarged original drawing of the oil holding recess 2b and reducing it by photographing, and the portion corresponding to the oil holding recess 2b is a non-transparent portion.

(I[[) When the above photomask is placed and irradiated with ultraviolet rays from a high-pressure mercury furnace (not shown), the portion of the resist film 4 irradiated with ultraviolet rays is cured by exposure, and the above photomask The portions that were blocked by the non-transparent portions and were not irradiated with ultraviolet light, that is, the portions corresponding to the oil holding recesses 2b, were not cured. After that, the photomask was removed and the resist film 4 was melted in the non-exposed portions made of trichloroethane. When developed with a liquid, the uncured portion is dissolved and peeled off,
As a result, an opening 4a is formed in a portion of the resist film 4 corresponding to the oil holding recess 2b, and this opening 4a portion of the chrome plating layer 2 is exposed to the outside.

(IV) When the chromium plating layer 2 on which the resist 1IllI4 is formed is etched, the exposed portions are melted and a large number of oil retaining recesses 2b are formed in the chrome plating layer 2 (Fig. 3(a) )reference).

(■゛) Then, without removing the resist film 4, molybdenum spray particles are projected from the plasma spray nozzle 5 toward the resist film 4 and the oil holding portion 2b. Then, since the resist film 4 is much softer than the chrome plating layer, the sprayed particles on the resist film 4 easily adhere to the resist film 4 without scattering to the surroundings, and also retain oil. Since there are no scattered particles as described above, the particles sprayed onto the recess 2b are easily and reliably stacked in the recess 2b (see FIGS. 3(b) and 3(C)).

(Vl) Finally, when the sliding contact member is immersed in a resist film melt made of methylene chloride, the resist film 4 is removed, and along with this, the resist)l! ! Sprayed layer 3 on 14
a is also removed, thereby obtaining a sliding member in which a porous molybdenum sprayed layer 3 having a lubricating oil retaining function is formed only in the oil retaining recess 2b (see FIG. 3(d)).

In this example, molybdenum thermal spraying was performed with the ultraviolet-cured resist (IFJ4) remaining after photoetching, so that the thermal spray particles on this resist film 4 would adhere to the film and scatter to the surroundings. Therefore, the spraying into the oil holding recess 2b is not hindered by the above-mentioned scattered particles, and as a result, the thermal spraying layer 3 is formed inside the oil holding recess 2b.
can be formed easily and reliably.

Normally, when thermal spray particles collide with an organic film such as a resist film, the film is thought to melt due to the heat, but a resist film cured by ultraviolet rays has high heat resistance and is soft. Therefore, it is thought that the thermal spray particles easily adhere to the resist film without dissolving the resist film.

Conversely, the surface of the chrome plating layer 2 is protected by the resist film 4, so the surface of the chrome plating layer 2 does not become rough, and the sprayed layer on the resist film 4 The resist film 4 can be easily removed by simply immersing it in the same resist film stripping agent as in the prior art.

Next, a comparative test for explaining the effects of the method of this example will be explained.

In this comparative test, the oil retaining recess 2 was
This is to show that the thermal spraying efficiency within b is improved.
In Comparative Example 1, thermal spraying was performed after removing the resist film 4 after photo-etching, and in Comparative Example 2, the resist film 4 was removed after photo-etching to prevent spraying particles from scattering on the surface of the chrome plating layer 2. Thermal spraying was performed after a blasting process was carried out to achieve this.

I Test conditions fil Photoetching conditions Photoresist: Film type (Resist layer thickness 15μ.

resolution 30μ) Photomask: Halftone type (Dot diameter 100μ.

Area ratio 10%) Developer: 111) Lichloroethane ethosing solution =
Cr03 (250g/p) and H2SO4 (2,
5g/I solution (2+R) Spraying conditions Thermal spraying material: Mo for thermal spraying (particle size 1o~44μ) Thermal spraying type:
Plasma spraying output: 35KW Distance F@: ]OOm/m Number of sprays: 10 passes (3) Resist film stripping solution after spraying: methylene chloride ■, test results Table 4 Here, the filling rate in Table 4 is as follows: This is the ratio (percentage) of the cross-sectional area of the sprayed layer 3 portion inside this recess 2b and the vertical cross-sectional area of the recess 2b when the oil holding recess 2b is cut in the longitudinal direction. This means that the thermal spraying was carried out easily, reliably and efficiently.

As is clear from the above test results (Table 4), in the method of this embodiment, the inner metal body of the oil holding recess 2b is filled with thermal spray particles, whereas in Comparative Example 1, the inner metal body of the oil holding recess 2b
It is almost impossible to spray inside the recess 2b.
This is the result of inward thermal spraying being obstructed by flying particles. Further, in Comparative Example 2, blasting was performed to prevent sprayed particles from scattering, but even if the chrome plating surface is roughened in this way, a sprayed layer can only be formed on the bottom surface of the oil holding recess 2b.

In addition, the above 1. In the embodiment of the second invention, a case has been described in which the hard plating layer 2 is a chrome plating layer and the thermal spraying material is molybdenum, but it goes without saying that the plating layer and the thermal spraying material are not limited to these. For example, the hard plating layer preferably has a hardness of HV700 or more, such as a near-kerlin (N i P) plating layer, and the thermal spraying material may be chromium kerosene (Cr3 C2). Further, in both of the above embodiments, the cylinder lychee was used as an example of the sliding member, but the present invention can of course be applied to sliding members other than the cylinder lychee.

[Effects of the Invention] As described above, according to the sliding contact member according to the first invention of the present application, a large number of recesses are provided in the hard plating layer, and a porous sprayed layer is formed in the recesses. It has the effect of improving the adhesion between the hard plated part of the metal and the thermal sprayed layer, and the thermal sprayed layer has oil retention properties, and the properties of the thermal sprayed layer itself can be used, so it improves lubricity and increases wear resistance. (There is an effect that can be improved.

Further, according to the method for manufacturing a sliding contact member according to the second invention of the present application, after forming a recess by photoetching on the entire bottom member having a sliding contact surface, a thermal spraying material is sprayed with a resist film remaining. Therefore, by using a simple configuration in which the resist film used for photoetching is used as is, this resist II prevents the sprayed particles from scattering, and protects the sliding surface from the collision of the sprayed particles. Therefore, the sprayed layer can be efficiently formed within the recessed portion, and the surface roughness of the sliding contact surface can be prevented from occurring.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing a sliding contact member according to an embodiment of the first invention of the present application, FIG. 2 is a schematic configuration diagram of a test device thereof, and FIG.
Figures (a) to fdl are process diagrams for explaining a method according to an embodiment of the second invention of the present application. ■...Metal base material, 2...Hard plating layer, 2a...
Sliding surface, 2b... oil holding recess, 3... thermal spray layer,
3a... Thermal spray layer on the resist film, 4... Resist film. Patent Applicant: Mazda Motor Corporation Agent, Patent Attorney Ken Hayase - Figure 1 h Figure 2 3 (G) (b) Figure (C) (d)

Claims (3)

[Claims] (1) Providing a hard plating layer with a sliding surface on a metal base material,
A sliding contact member with excellent wear resistance, characterized in that a large number of recesses are provided on the sliding surface of the plated layer, and a porous sprayed layer having a lubricant retaining function is provided only in the recesses. (2) A sliding contact member with excellent wear resistance as set forth in claim 1, wherein the thermal sprayed layer is formed of a thermally sprayed material of molybdenum. (3) After forming a large number of recesses by photo-etching on a metal member having a sliding surface, a thermal spraying material is sprayed with a photo-etching resist film remaining on the metal member, and then the resist film and A sliding contact member with excellent wear resistance characterized in that the thermal sprayed layer on the resist film is removed to obtain a sliding contact member in which a porous thermal sprayed layer having a lubricant retaining function is formed only in the recess. Production method.