JP2019108589A - Slide member and method for producing slide member - Google Patents

Abstract

To provide a technique that can flexibly control the thickness of a bearing layer and the content of a material.SOLUTION: A slide member has a base material, a porous plating part that is formed on the base material and is a porous plating film of a first metal, and a filling part in which a hole of the porous plating part is filled with a second metal different from the first metal.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a sliding member and a method of manufacturing the sliding member.

  There is disclosed a technology in which an alloy layer of Cu and Bi formed by sintering is used as a slide bearing material (see Patent Document 1). In Patent Document 1, an alloy layer of Cu and Bi is formed such that particles of Bi are dispersed in Cu.

Patent No. 54033636

However, as in Patent Document 1, there is a problem that it is difficult to form a thin alloy layer by sintering. In addition, since a part of Bi is solid-solved in Cu during sintering, there is a problem that the amount of Bi present as particles of a single Bi can not be increased.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a technique capable of flexibly adjusting the film thickness of the bearing layer and the content ratio of the material.

  In order to achieve the above object, the sliding member of the present invention comprises a substrate, a porous plating portion which is a porous plating film of a first metal formed on the substrate, and the porous plating portion And a filling portion filled with a second metal different from the first metal in the hole of

  In the present invention configured as described above, since the porous plating portion is a plating film, it is possible to flexibly adjust the film thickness including thinning. Moreover, since the filling part is filled in the pores of the porous plating part formed as the plating film, the amount of the second metal dissolved in the first metal of the porous plating part can be suppressed. Therefore, the amount of the second metal present as a single substance can be flexibly adjusted.

  Here, the first metal may be Cu and the second metal may be Bi. By combining hard Cu and soft Bi, it is possible to form a sliding member having both wear resistance and conformability.

  Furthermore, the first metal may be Cu and the second metal may be Sn. By combining hard Cu and soft Sn, it is possible to form a sliding member having both wear resistance and conformability. In addition, it is possible to generate a hard Sn-Cu intermetallic compound by the heat at the time of using the sliding member, and it is possible to further improve the wear resistance.

  The first metal may be Ni, and the second metal may be Bi. By combining hard Ni and soft Bi, it is possible to form a sliding member having both wear resistance and conformability. In addition, a hard Ni-Bi intermetallic compound can be generated by heat during use of the sliding member, and wear resistance can be further improved.

  Further, according to the present invention, a plating step of forming a porous plating portion of a first metal by plating on a substrate, and a filling step of filling a hole of the porous plating portion with a second metal different from the first metal And a method of manufacturing a sliding member including the above.

It is a perspective view of a sliding member concerning an embodiment of the present invention. 2A and 2B are cross-sectional schematic views of the sliding member.

Here, embodiments of the present invention will be described in the following order.
(1) First Embodiment:
(1-1) Configuration of sliding member:
(1-2) Manufacturing Method of Sliding Member:
(2) Other embodiments:

(1) First Embodiment:
(1-1) Configuration of sliding member:
FIG. 1 is a perspective view of a sliding member 1 according to an embodiment of the present invention. The sliding member 1 includes a back metal 10 and a lining 11. The sliding member 1 is a metal member in the shape of a half in which a hollow cylinder is divided into two in the diameter direction, and the cross section thereof has a semicircular arc shape. The sliding bearing A is formed by combining the two sliding members 1 in a cylindrical shape. The slide bearing A bears a cylindrical counterpart shaft 2 (engine crankshaft) at a hollow portion formed inside. The outer diameter of the mating shaft 2 is formed slightly smaller than the inner diameter of the slide bearing A. Lubricating oil (engine oil) is supplied to the gap formed between the outer peripheral surface of the countershaft 2 and the inner peripheral surface of the slide bearing A. At this time, the outer peripheral surface of the mating shaft 2 slides on the inner peripheral surface of the slide bearing A.

  The sliding member 1 has a structure in which the back metal 10 and the lining 11 are sequentially stacked in order of distance from the center of curvature. Therefore, the back metal 10 constitutes the outermost layer of the sliding member 1, and the lining 11 constitutes the innermost layer of the sliding member 1. The back metal 10 and the lining 11 each have a constant thickness in the circumferential direction. The thickness of the back metal 10 is 1.8 mm, and the thickness of the lining 11 is 50 μm. Hereinafter, the inner side means the center of curvature of the sliding member 1, and the outer side means the side opposite to the center of curvature of the sliding member 1. The inner surface of the lining 11 constitutes a sliding surface of the countershaft 2.

  The back metal 10 constitutes the base material of the present invention. The back metal 10 is formed of steel containing 0.15 mass% of C, 0.06 mass% of Mn, and the balance of Fe. In addition, the back metal 10 should just be formed with the material which can support the load from the other axis | shaft 2 through the lining 11, and does not necessarily need to be formed with steel.

  The lining 11 is a layer laminated on the inner side of the back metal 10, and constitutes the porous plating portion and the filling portion of the present invention. The lining 11 is composed of 40% by mass of Cu, 60% by mass of Bi and unavoidable impurities, and the content of the unavoidable impurities is 1.0% by mass or less. Cu is a first metal and Bi is a second metal.

  2A and 2B are schematic cross-sectional views of the sliding member 1. FIG. 2A shows the lining 11 after being filled with Bi, and FIG. 2B shows the lining 11 before being filled with Bi. In FIG. 2A, the lining 11 has a porous plating portion 11a (black) formed of Cu and a filling portion 11b (dot hatching) formed of Bi in the porous plating portion 11a.

  As shown to FIG. 2B, the hole 11a1 (white) is formed in the porous plating part 11a, and the filling part 11b is formed by filling Bi with the said hole 11a1. The holes 11a1 of the porous plating portion 11a are equally distributed in the inner circumferential direction and the thickness direction of the sliding member 1. Further, the holes 11a1 of the porous plating portion 11a are those in which a large number of holes communicate with each other, and are substantially integral spaces. Therefore, the filling part 11b is also substantially integral. That is, the filling portion 11 b is in the shape of being meshed around in the lining 11.

  In the embodiment described above, since the porous plating portion 11 a is a plating film, the film thickness can be flexibly adjusted including the reduction in thickness. Moreover, since the filling part 11b is filled in the hole of the porous plating part formed as a plating film, it can suppress the quantity which Bi dissolves into Cu of the porous plating part 11a. Therefore, the amount of Bi present as a single substance can be flexibly adjusted. Furthermore, by combining hard Cu as the first metal and soft Bi as the second metal, it is possible to form the sliding member 1 having both wear resistance and conformability.

  Each numerical value shown in the embodiment described above was measured by the following method. The mass of the element constituting each layer of the sliding member 1 was measured by an ICP emission spectrometer (ICPS-8100 manufactured by Shimadzu Corporation). The thickness of each layer was measured by the following procedure. First, the vertical cross section of the sliding member 1 in the axial direction was polished with a cross section polisher (IB-09010 CP, manufactured by Nippon Denshi K.K.). And the image data of the observation image (reflection electron image) was obtained by image | photographing the cross section of the sliding member 1 by the magnification of 7000 times with the electron microscope (JSM-6610A made from JEOL). Then, the film thickness was measured by analyzing the observation image with an image analyzer (Lusex AP manufactured by Nireco).

(1-2) Manufacturing Method of Sliding Member:
First, a flat plate of low carbon steel having the same thickness as the backing metal 10 was prepared.
Next, a lining 11 was formed by laminating Cu to a thickness of 50 μm on the surface of the back metal 10 by electroplating. The procedure of electroplating was as follows. First, the surface of the back metal 10 was washed with water. Furthermore, the unnecessary oxide was removed from the surface of the back metal 10 by pickling the surface of the back metal 10. Thereafter, the surface of the back metal 10 was washed again with water.

  When the above pretreatment was completed, electroplating was performed by supplying a current to the back metal 10 immersed in the plating bath. A plating bath is prepared by mixing copper pyrophosphate: 94 g / L, potassium pyrophosphate: 340 g / L, aqueous ammonia: 3 mL / L, polyphosphoric acid neutralized benzyltrimethylammonium hydroxide: 0.05 mol / L. did. Benzyltrimethylammonium hydroxide is a water soluble quaternary ammonium compound.

  As an ammonium compound, in place of benzyltrimethylammonium hydroxide, dodecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, octadecyltrimethylammonium chloride, phenyltrimethylammonium chloride described in JP-A-2010-121194 Benzyltrimethyl ammonium chloride, benzyl triethyl ammonium chloride, benzyl tributyl ammonium chloride, didecyl dimethyl ammonium chloride, dodecyl dimethyl benzyl ammonium chloride, tetradecyl dimethyl benzyl ammonium chloride, octadecyl dimethyl benzyl ammonium chloride, Octyl methyl ammonium chloride, dodecyl pyridinium chloride, benzyl pyridinium chloride, these bromides, may be mixed into the plating bath, such as sulfate alone or in combination.

The bath temperature of the plating bath adjusted as described above was 55.degree. Further, the current supplied to the back metal 10 is a direct current, and the current density is 3 A / dm ² . In electroplating, the plating bath (liquid) was kept stationary without liquid flow. The plating bath can be adjusted in the range of 70 to 110 g / L of copper pyrophosphate, 260 to 400 g / L of potassium pyrophosphate, and 2 to 4 mL / L of aqueous ammonia. The bath temperature can be adjusted in the range of 50 to 60 ° C., and the current density can be adjusted in the range of 0.5 to 5.0 A / dm ² . The addition amount of the ammonium compound can be adjusted in the range of 0.001 to 0.1 mol / L.

  The ammonium compound is reductively decomposed at the cathode interface during electroplating, and the non-water-soluble free substance generated by the decomposition is scattered on the plating surface. It is considered that a porous plating film having a large number of fine pores is formed by the liberated substance inhibiting the growth of the plating film of Cu. Since this phenomenon occurs from the early stage of electroplating, a porous plating film can be formed in the entire thickness direction of the lining 11. After completion of the above electroplating (plating step), water washing and drying were performed.

  In addition, the volume ratio of the hole in the lining 11 can be made to increase by making the current density in electroplating high, and the volume ratio of the filling part 11b in the lining 11 can be made to increase. By increasing the volume ratio of the filling portion 11b, it is possible to form the sliding member 1 emphasizing low friction resistance and conformability, and by reducing the volume ratio of the holes 11a1, the sliding member 1 emphasizing wear resistance is obtained. It can be formed.

  Furthermore, the filling part 11b was formed by filling Bi by the electroplating to the hole 11a of the porous plating part 11a. The procedure of electroplating was as follows. First, the porous plating part 11a was washed with water. Further, the porous plating portion 11a was pickled to remove unnecessary oxides from the porous plating portion 11a. Thereafter, the porous plated portion 11a was washed again with water.

When the above pretreatment was completed, electroplating was performed by supplying a current to the back metal 10 on which the porous plated portion 11a immersed in the plating bath was formed. It was set as the bath composition of the plating bath which contains organic sulfonic acid Bi: 20 g / L (Bi concentration), organic surfactant: 20 mL / L, and organic sulfonic acid: 100 g / L. A polyethylene glycol solution was used as an organic surfactant. The bath temperature of the plating bath was 30.degree. Further, the current supplied to the metal backplate 10 on which the porous plated portion 11a is formed is a direct current, and the current density is 2.0 A / dm ² . After completion of the electroplating (filling step), water washing and drying were performed.

  In addition, if all the holes 11a are connected to the surface of the porous plating part 11a, a plating solution will spread over all the holes 11a, and all the holes 11a will be filled. As the volume ratio of the holes 11a1 in the porous plating portion 11a is increased, the holes 11a1 can be more easily communicated, and the holes 11a filled with Bi can be increased. However, since the conformability can be improved by the holes 11 a not filled with Bi, all the holes 11 a may not be filled with Bi. Also, although it is desirable that the electroplating of Bi is completed when the crystals of Bi grow to the surface of the porous plated portion 11a, the electroplating of Bi is completed before reaching the surface of the porous plated portion 11a. Alternatively, electroplating of Bi may be continued until the entire surface of the porous plated portion 11a is covered with Bi.

  As described above, when the sliding member 1 is completed, the sliding bearing A is formed by combining the two sliding members 1 in a cylindrical shape.

(2) Other embodiments:
In the present invention, the first metal may be Cu and the second metal may be Sn. That is, the holes 11a of the porous plating portion 11a formed in the same manner as the above embodiment may be filled with Sn. The Sn filling step can be performed by electroplating under the following conditions. The bath composition of the plating bath containing 25 g / L (Sn concentration) of organic sulfonic acid, 5 mL / L of organic surfactant and 100 g / L of organic sulfonic acid may be used. A polyethylene glycol solution may be used as the organic surfactant. The bath temperature of the plating bath was 25 ° C. Furthermore, the current supplied to the metal backplate 10 on which the porous plated portion 11a is formed may be a direct current, and the current density may be 4.0 A / dm ² .

  As described above, by combining hard Cu and soft Sn, it is possible to form a sliding member having both wear resistance and conformability. In addition, it is possible to generate a hard Sn-Cu intermetallic compound by the heat at the time of using the sliding member, and it is possible to further improve the wear resistance.

The first metal may be Ni, and the second metal may be Bi. That is, the porous plated portion 11a of the first embodiment may be formed of Ni. The plating process of Ni can be performed by electroplating under the following conditions. A plating bath may be prepared by mixing nickel sulfate: 280 g / L, nickel chloride: 45 g / L, boric acid: 40 g / L, dodecyltrimethylammonium chloride: 0.02 mol / L. Furthermore, the temperature of the plating bath may be 50 ° C., the current supplied to the back metal 10 may be a direct current, and the current density may be 5.0 A / dm ² .

  When the porous plating portion 11a is formed, Bi may be filled in the holes 11a1 of the porous plating portion 11a by the same filling process as in the first embodiment. Thus, by combining hard Ni and soft Bi, it is possible to form a sliding member having both wear resistance and conformability. In addition, a hard Ni-Bi intermetallic compound can be generated by heat during use of the sliding member, and wear resistance can be further improved.

  In the said embodiment, although the sliding member 1 which comprises the sliding bearing A which bears the crankshaft of an engine was illustrated, you may form the sliding bearing A of another use by the sliding member 1 of this invention. For example, the sliding member 1 of the present invention may form a radial bearing such as a gear bushing for a transmission or a piston pin bushing or boss bushing. Furthermore, the sliding member of the present invention may be a thrust bearing, may be various washers, or may be a swash plate for a car air conditioner compressor. The lining 11 may be covered by a metal or resin overlay.

DESCRIPTION OF SYMBOLS 1 ... Sliding member, 2 ... Countering axis, 10 ... Back metal, 11 ... Lining, A ... Bearing

Claims (5)

A substrate,
A porous plating portion which is a porous plating film of a first metal formed on the substrate;
A filling portion in which holes of the porous plating portion are filled with a second metal different from the first metal;
A sliding member comprising: The first metal is Cu, and the second metal is Bi.
The sliding member according to claim 1. The first metal is Cu, and the second metal is Sn.
The sliding member according to claim 1. The first metal is Ni, and the second metal is Bi.
The sliding member according to claim 1. Forming a porous plated portion of the first metal on the substrate by plating;
Filling the pores of the porous plating portion with a second metal different from the first metal;
A method of manufacturing a sliding member including:

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