JP2019151913A - Sliding member and method for manufacturing the same - Google Patents

Abstract

To provide a sliding member capable of reducing friction and maintaining the state thereof for a long time, and a method for manufacturing the same.SOLUTION: A sliding member 10 includes a base material 1 consisting of steel and an alloy layer 2 formed on the surface of the base material 1. A dispersion layer 1b having metal particles 1a: having a diameter of 0.01 μm-2.0 mm; including one or more kinds selected from Sn, Bi and In; and dispersed at a number density of 50.0 pieces/cmor more exists in the surface layer part of the base material 1; the thickness of the dispersion layer 1b is 20.0-2000 μm; the alloy layer 2 includes one or more kinds selected from Sn, Bi and In, and Fe; the total content of Sn, Bi and In is 10.0-75.0% by mass%; and the thickness of the alloy layer is 3.0-100 nm.SELECTED DRAWING: Figure 1

Description

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

  Sliding members used in automobile crankshafts and the like are required to have excellent sliding characteristics from the viewpoint of fuel efficiency in addition to wear resistance, and in particular, reduction of friction on the member surface is required. Yes.

  In ordinary steel materials, seizure often becomes a problem when sliding in a non-lubricating oil environment (dry environment) or a lubricating oil environment. Therefore, various measures are taken to prevent burn-in. For example, in a dry environment, measures are taken by DLC film formation or coating with PTFE fluororesin.

  Further, Patent Document 1 discloses a sliding member excellent in durability and reliability in which both the sliding member itself and the counterpart shaft material are less worn even when used under high speed rotation and high load. Further, Patent Document 2 discloses a sliding component plating film excellent in seizure resistance and wear resistance and a sliding component coated with the plating film.

  In Patent Document 3, even when an inexpensive solid lubricating film is used, the adhesion between the solid lubricating film and the member does not decrease, a low friction coefficient can be obtained over a long period of time, and high wear resistance can be maintained. A membraned member is disclosed.

JP-A-4-325697 International Publication No. 2004/063426 JP 2000-178720 A

  In general, seizure phenomenon on steel parts or steel surfaces is caused by chemical factors (for example, at the sliding interface in a high temperature and high pressure environment in addition to physical factors such as those derived from wear powder generated during sliding) It is governed by the generation of dissimilar materials that may be caused by chemical reactions such as transfer or adhesion of the sliding material. That is, a burn-in phenomenon occurs as a result of complicated and complicated physical or chemical factors.

  When the above-described DLC film formation is performed on the surface of the steel part, good surface properties can be obtained. However, there are concerns about unexpected thermal shock and stress concentration in a high temperature and high pressure environment during sliding. At present, DLC film formation cannot be said to sufficiently resist such an environment. Although the above-mentioned fluororesin coating is a convenient and low-cost surface treatment method, it is toxic in high-temperature environments in addition to premature corrosion degradation that may be caused by pinholes formed inside the fluororesin. There are environmental concerns such as the possibility of certain hazardous gases. As described above, the above-described method has a limit in sufficiently suppressing the seizure phenomenon on the steel surface and maintaining good sliding performance.

  Moreover, in patent documents 1 and 2, since the film by plating is formed on the surface of the base material, the thickness of the film is as thick as several μm or more. Therefore, there exists a possibility that a membrane | film | coat may peel at the time of sliding. Therefore, there is a problem with the durability of the film.

  According to the member with a solid lubricating film described in Patent Document 3, since the adhesion between the solid lubricating film and the member does not deteriorate, a low friction coefficient is obtained over a long period of time, and high wear resistance can be maintained. Yes. However, when the solid lubricating film on the surface is worn, the solid lubricating film deposited in the dent is dug up and oozes out, but the exposed base material may come into contact with the counterpart material at that time Therefore, there is a possibility that the sliding characteristics cannot be maintained.

  An object of the present invention is to solve the above problems, to provide a sliding member capable of reducing friction and maintaining the state for a long time, and a manufacturing method thereof.

  The present invention has been made to solve the above-described problems, and provides the following sliding member and a manufacturing method thereof.

(1) A base material made of steel and an alloy layer formed on the surface of the base material,
The surface layer portion of the base material has a diameter of 0.01 μm to 2.0 mm, and has a number density of 50.0 / cm ² or more of metal particles including one or more selected from Sn, Bi, and In. There is a dispersion layer to disperse,
The thickness of the dispersion layer is 20.0 to 2000 μm,
The alloy layer includes at least one selected from Sn, Bi and In and Fe, and the total content of Sn, Bi and In is 10.0 to 75.0% in mass%, And the thickness is 3.0 to 100 nm,
Sliding member.

(2) It further includes a metal layer formed on the surface of the alloy layer and made of one or more selected from Sn, Bi and In.
The sliding member according to (1) above.

(3) The contents of Sn, Bi, and In in the thickness center portion of the base material are all mass% and 0.01% or less.
The sliding member according to the above (1) or (2).

(4) A method for producing the sliding member according to any one of (1) to (3) above,
Heating a surface of a base material made of steel to a temperature range of 300 to 800 ° C .;
A peening step of peening metal fine particles containing one or more selected from Sn, Bi and In on the heated surface.
Manufacturing method of sliding member.

(5) The average particle diameter of the metal fine particles is 30 to 500 μm.
The manufacturing method of the sliding member as described in said (4).

(6) In the metal fine particles, the surface of fine particles made of steel is coated with one or more selected from Sn, Bi, and In.
The manufacturing method of the sliding member as described in said (4) or (5).

(7) In the heating step, the surface is heated by high frequency induction heating.
The manufacturing method of the sliding member in any one of said (4) to (6).

  According to the present invention, it is possible to obtain a sliding member that is excellent in sliding characteristics and that maintains its state for a long time.

It is a figure which shows schematic structure of the sliding member which concerns on one Embodiment of this invention. It is a conceptual diagram for demonstrating the manufacturing method of the sliding member which concerns on one Embodiment of this invention.

  FIG. 1 is a diagram showing a schematic configuration of a sliding member according to an embodiment of the present invention. With reference to FIG. 1, a sliding member 10 according to an embodiment of the present invention includes a base material 1, an alloy layer 2, and a metal layer 3. The alloy layer 2 is formed on the surface of the substrate 1, and the metal layer 3 is formed on the surface of the alloy layer 2. Note that the metal layer 3 may not be formed.

  The alloy layer 2 contains one or more selected from Sn, Bi, and In and Fe. The total content of Sn, Bi and In is 10.0 to 75.0% by mass. Specifically, the alloy layer 2 includes an alloy containing Sn and Fe, an alloy containing Bi and Fe, an alloy containing In and Fe, or two or three selected from Sn, Bi and In and Fe. Composed of alloy. And the thickness of the alloy layer 2 is 3.0-100 nm.

  In addition, the alloy here means containing a plurality of metal atoms, and is not necessarily limited to being regularly arranged in a lattice form at the atomic level. This is because even a high-resolution surface analyzer such as an Auger electron spectroscopic analyzer can only obtain average information of about 1 nm in the depth direction and the surface direction. For example, even when one or more metal layers selected from sub-nano-order Sn, Bi and In are formed on the dispersion layer, the actual surface is rough and the films of these layers Since the thickness is not necessarily uniform, it is obtained as information including the underlying Fe in the analysis, and as a result, it is expressed as a layer including a plurality of metal atoms as described above.

  Sn, Bi and In are very soft metals, and alloys containing them are also soft. Therefore, when the soft alloy layer 2 is formed on the surface of the substrate 1, the alloy layer 2 serves as a lubricating film. As a result, friction with a member that is a sliding partner (also referred to as “mating member”) is reduced, and the sliding characteristics of the substrate 1 can be improved.

  If the thickness of the alloy layer 2 is less than 3.0 nm, the effect of improving the sliding characteristics is insufficient. On the other hand, if the thickness exceeds 100 nm, the contact resistance with the member to be slid increases and the sliding characteristics deteriorate.

  The metal layer 3 is made of one or more selected from Sn, Bi and In. That is, pure Sn, pure Bi, pure In, Sn and Bi alloy, Sn and In alloy, Bi and In alloy, and Sn, Bi and In alloy are included. By forming the metal layer 3 on the surface of the alloy layer 2, it is possible to further reduce friction. The “alloy” herein refers to a mixture of two or three metals selected from Sn, Bi and In, and does not necessarily have to be mutually dissolved.

  As described above, the metal layer 3 may not be formed. However, if formed, if the thickness is excessive, the sliding characteristics may be deteriorated. Therefore, the thickness of the metal layer 3 is preferably 1000 μm or less. On the other hand, the lower limit is not particularly limited, but can be set to 3.0 μm or more, for example, when it is desired to obtain a friction reducing effect by the metal layer 3.

Further, in the surface layer portion of the substrate 1, there is a dispersion layer 1b in which metal particles 1a containing one or more selected from Sn, Bi and In are dispersed. In the present invention, the dispersion layer 1b refers to a layer in which metal particles 1a having a diameter (equivalent circle diameter) of 0.01 μm to 2.0 mm are dispersed at a number density of 50.0 / cm ² or more. And The thickness of the dispersion layer 1b is 20.0 to 2000 μm.

The metal particles 1a need not all be the same component. For example, all metal particles may contain two or three kinds selected from Sn, Bi and In, or metal particles containing Sn, metal particles containing Bi, and metal particles containing In are dispersed separately. You may do it. In that case, a layer in which the total number density of the metal particles containing Sn, the metal particles containing Bi, and the metal particles containing In is 50.0 particles / cm ² or more is defined as a dispersion layer 1b.

  The alloy layer 2 and the metal layer 3 functioning as a lubricating film are consumed by sliding with the mating member. The metal layer 3 is consumed at the beginning of sliding. However, when one or more of Sn, Bi, and In and Fe diffuse from the dispersion layer 1b to the surface of the base material, the alloy layer 2 is regenerated and maintained for a long time. Sn, Bi, and In have the property of rapidly diffusing to the surface of the substrate 1 even in a room temperature environment.

If the diameter of the metal particles 1a in the dispersion layer 1b is less than 0.01 μm, it is difficult to contribute to the regeneration of the alloy layer 2. On the other hand, when it exceeds 2.0 mm, it becomes difficult to make the number density 50.0 pieces / cm ² or more.

  If the thickness of the dispersion layer 1b is less than 20.0 μm, the amount of one or more selected from Sn, Bi and In that can be supplied is small, and it becomes difficult to maintain the alloy layer 2 for a long time. On the other hand, if the thickness exceeds 2000 μm, the mechanical properties in the surface layer portion of the substrate 1 may be deteriorated. Therefore, the thickness of the dispersion layer 1b is 20.0 to 2000 μm.

  The substrate 1 is made of steel. As the steel, for example, ferritic steel, austenitic steel, martensitic steel, or steel having a structure of two or more phases can be used. Moreover, there is no restriction | limiting also about the dispersion | distribution and solid solution state of the precipitate in a structure | tissue.

  Note that Sn, Bi, and In tend to segregate not only on the surface but also on the grain boundaries. Therefore, if these elements are contained in a large amount in the base material 1, they segregate at the crystal grain boundaries of the base material 1, causing brittle fracture and intergranular corrosion. Therefore, it is preferable to limit the region containing a large amount of these elements only to the surface layer portion of the substrate 1. That is, in the thickness center part of the base material 1, the contents of Sn, Bi, and In are all mass%, and preferably 0.01% or less.

  Although there is no restriction | limiting in particular about the method of manufacturing the sliding member 10 which has said structure, For example, it can manufacture by the method shown below.

  The manufacturing method of the sliding member 10 which concerns on one Embodiment of this invention is the heating process which heats the surface of the base material 1 which consists of steel to the temperature range of 300-800 degreeC, and the surface of the heated base material 1 is used. And a peening process of peening the metal fine particles 11 containing one or more selected from Sn, Bi, and In.

  Drawing 2 is a key map for explaining the manufacturing method of the sliding member concerning one embodiment of the present invention. Referring to FIG. 2, a metal containing one or more selected from Sn, Bi, and In in the interior of substrate 1 by peening metal fine particles 11 on the surface of substrate 1 heated to a high temperature. The particles 1a can be physically dispersed. As a result, the dispersion layer 1 b is formed on the surface layer portion of the substrate 1, and the alloy layer 2 is formed on the surface of the substrate 1. Further, a metal layer 3 is further formed on the surface of the alloy layer 2 according to the peening time.

  When the surface temperature of the base material 1 is less than 300 ° C., the base material 1 is not sufficiently softened, and the deformation and folding effects of the surface layer portion due to peening become insufficient, and the dispersion layer 1b satisfying the above-mentioned regulations may be formed. It becomes difficult. On the other hand, when the surface temperature exceeds 800 ° C., the metal fine particles 11 collide with the surface and melt at the same time to cover the surface, and the peening effect cannot be obtained. It becomes difficult to form. Further, when the surface temperature is too high, one or more of Sn, Bi, and In are immediately segregated from the formed dispersion layer 1b, and the dispersion layer 1b may disappear.

  There is no restriction | limiting in particular about the heating method of the surface of the base material 1, For example, a high frequency induction heating is employable.

  Further, the size of the metal fine particles 11 is not particularly limited. However, in order to sufficiently exhibit the effect of diffusion into one or more kinds selected from Sn, Bi and In, the average particle size is 30 to 30. It is preferable that it is 500 micrometers.

  Since Sn, Bi, and In are soft, it is difficult to diffuse the inside of the base material even when peening pure Sn, pure Bi, pure In, or the like. Therefore, for example, it is preferable to use, as the fine metal particles 11 for peening, particles in which the surface of fine particles made of steel is coated with one or more selected from Sn, Bi, and In.

  For example, the surface of a steel ball is coated with one or more types selected from Sn, Bi and In by mixing a steel ball and one or more types of particles selected from pure Sn, pure Bi and pure In in a ball mill. can do. At this time, a steel ball whose surface is coated with Sn, Bi, and In may be prepared by mixing steel balls, pure Sn particles, pure Bi particles, and pure In particles in the same ball mill. Alternatively, a steel ball coated with Sn on the surface, a steel ball coated with Bi on the surface, and a steel ball coated with In on the surface may be separately prepared and used. Further, one or more types of coating selected from pure Sn, pure Bi and pure In may be applied to the surface of the steel ball by electrolytic or electroless powder plating or various vapor depositions.

  The peening time is not particularly limited, but is preferably 10 to 300 seconds. If the peening time is less than 10 seconds, the formation of the dispersion layer may be insufficient. On the other hand, when the peening time exceeds 300 seconds, not only the thickness of the metal layer 3 becomes excessive, but also the oxidation of the surface of the metal layer 3 proceeds and the lubricity may be lowered.

  Similarly, from the viewpoint of preventing oxidation of the metal layer 3, the peening process is preferably performed in an inert gas such as a nitrogen atmosphere, and the metal fine particles 11 are also preferably sprayed with an inert gas. Thereby, it is possible to prevent oxidation of the metal fine particles 11 themselves.

  Even if one or more selected from Sn, Bi and In are added at the casting stage of the base material 1, it is separated into two layers, and one or more selected from Sn, Bi and In is contained in the base material 1 It is not easy to disperse the metal particles 1a containing. By manufacturing the sliding member 10 by the above-described method, the metal particles 1a can be dispersed only in the surface layer portion of the base material 1, so that the sliding characteristics of the member can be achieved without deteriorating the mechanical characteristics of the base material. It becomes possible to improve.

  EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely, this invention is not limited to these Examples.

  Four types of JIS standard products were used as test materials. That is, in S45C steel (0.42C-0.20Si-0.70Mn-0.01S-0.10Cr) of carbon steel for mechanical structure specified in JIS G 4051 (2009), JIS G 5111 (1991). SCM3 steel (0.38C-0.53Si-1.50Mn-0.01P-0.01S), a structural high-strength carbon steel that is specified, carbon for mechanical structure specified in JIS G 4053 (2016) Steel SCM435 (0.35C-0.20Si-0.75Mn-0.10Ni-1.00Cr-0.20Mo), alloy tool steel SKD11 steel (1) defined in JIS G 4404 (2006) .50C-0.20Si-0.40Mn-0.01P-0.01S-12.0Cr-1.00Mo-0.30V).

  For S45C steel, two types of quenching material (from 870 ° C. to water cooling) and annealing material (from 810 ° C. to furnace cooling), for SCMn3 steel, quenching and tempering material (from 1000 ° C. after oil quenching and tempering at 400 ° C.) Was used. The SCM435 steel used a quenching and tempering material (from 900 ° C. after oil quenching and tempering at 600 ° C.), and the SKD11 steel was a quenching and tempering material (quenching: air cooling from 1030 ° C., low temperature tempering: air cooling from 180 ° C.). The test material was formed into a disk shape (diameter: 15 mm × thickness: 4 mm) by machining, and the coating surface to be described later was further finished to a mirror surface.

  Subsequently, the test material was tested using a device in which a high frequency power source, a heating high frequency induction heating (hereinafter referred to as “IH”) coil and an output control panel were combined with a fine particle peening (hereinafter referred to as “FPP”) device The film was processed. In other words, the apparatus used in this example includes a cylindrical IH coil (inner diameter: 40 mm, winding number: 4, width: 35 mm) inside an FPP apparatus having a metal fine particle projection nozzle (inner diameter: 6 mm).

  By placing the test material installed on the refractory brick inside the IH coil, the test material was heated in a non-contact manner. Then, the surface of the test material was heated to the temperature shown in Table 1 within 1 second, and the FPP treatment was performed on the surface while maintaining the temperature. Then, the injection of the metal fine particles was stopped and quenched with the compressed gas supplied from the nozzle tip. This treatment was performed under nitrogen atmosphere control.

  The supply amount of the particle projection was 2.0 g / sec, the injection pressure was 0.54 MPa, the distance between injections was 100 mm, and the injection was performed for the time shown in Table 1. As the metal fine particles subjected to injection, steel balls coated with Sn were used. Specifically, steel balls (1.00C-0.50Si-0.6Mn, Hv800) having an average particle diameter of 100 μm and Sn particles (diameter 100 μm, purity 99.99%) were placed in a ball mill at 100 rpm for 2 hours. By mixing, Sn was coated with Sn to a thickness of about 10 μm.

  In addition, Test No. For the 14 test materials, the FPP treatment was not performed. In addition, Test No. About 15 test materials, Sn plating was given instead of FPP processing.

Test No. For each of the test materials 1 to 13, the surface structure was first analyzed. Specifically, the composition and thickness of the alloy layer formed on the surface of the base material and the thickness of the metal layer are measured by depth direction analysis using an Auger spectroscopic analyzer (SAM670 manufactured by ULVAC-PHI). did. In addition, the thickness of the dispersion layer present on the surface layer of the base material is repeatedly buffed from the surface, and the number of metal particles having a diameter of 0.01 μm to 2.0 mm present on the surface is counted repeatedly. It was determined by determining the relationship between the cutting depth and the number density. The thickness of the dispersion layer was the distance from the surface to the depth where the number density of the metal particles was less than 50.0 / cm ² . That is, when the dispersion layer is cut along a plane parallel to the surface, 50.0 particles / cm ² or more of 0.01 μm to 2.0 mm metal particles are present.

  Subsequently, the friction characteristics were evaluated by a ball-on-disk friction test (Tribometer manufactured by CSM Instruments). A commercially available SUJ2 ball having a diameter of 6 mm was used, and a friction test was performed under the conditions of a load of 10 N, a friction speed of 10 mm / second, a friction time of 60 minutes, and no lubricant. As the coefficient of friction, a value provided from the tester software was used. Then, the average friction coefficient for 1 minute from the start of friction was measured as the “initial friction coefficient”, and the friction time until the friction coefficient exceeded 0.3 was evaluated as the durability of low friction. In the present invention, when the initial friction was 0.20 or less and the durability of low friction was 15 minutes or more, it was judged that the sliding characteristics were excellent.

  The results are summarized in Table 1.

  With reference to the results in Table 1, the test No. 1 satisfying the provisions of the present invention. 1 to 11, the initial friction was 0.20 or less and the durability of low friction was 15 minutes or more, resulting in excellent sliding characteristics. On the other hand, the surface temperature during FPP treatment is too low. In No. 12, no dispersion layer was formed in the substrate, resulting in poor low friction durability. In addition, the surface temperature is too high. In No. 13, the alloy layer and the metal layer were oxidized to oxides, resulting in poor friction characteristics. Furthermore, test No. which did not implement FPP processing. No. 14 resulted in a poor initial wear coefficient. And test No. with Sn plating on the surface. In No. 15, since the dispersion layer was not present in the substrate, the low friction durability was inferior.

  The same investigation as in Example 1 was further carried out using the above-mentioned four types of JIS standard equivalents as test materials. However, in the present example, the metal fine particles subjected to the injection in the FPP treatment were steel balls coated with Bi. Specifically, a steel ball (1.00C-0.50Si-0.6Mn, Hv800) having an average particle diameter of 100 μm and Bi particles (diameter 100 μm, purity 99.99%) were placed in a ball mill at 100 rpm for 1 hour. By mixing, a steel ball was coated with Bi to a thickness of about 10 μm.

  The other conditions are the same as in the first embodiment. In addition, Test No. For the 14 test materials, the FPP treatment was not performed. In addition, Test No. About 15 test materials, Bi plating was given instead of FPP processing.

  Test No. For each of the test materials 1 to 15, the surface structure was analyzed and the friction characteristics were evaluated in the same manner as in Example 1. The results are summarized in Table 2.

  With reference to the results in Table 2, test no. 1 to 11, the initial friction was 0.20 or less and the durability of low friction was 15 minutes or more, resulting in excellent sliding characteristics. On the other hand, the surface temperature during FPP treatment is too low. In No. 12, no dispersion layer was formed in the substrate, resulting in poor low friction durability. In addition, the surface temperature is too high. In No. 13, the alloy layer and the metal layer were oxidized to oxides, resulting in poor friction characteristics. Furthermore, test No. which did not implement FPP processing. No. 14 resulted in a poor initial wear coefficient. And test No. which gave Bi plating to the surface. In No. 15, since the dispersion layer was not present in the substrate, the low friction durability was inferior.

  The same investigation as in Example 1 was further carried out using the above-mentioned four types of JIS standard equivalents as test materials. However, in this example, the metal fine particles subjected to the injection in the FPP treatment were those in which steel balls were coated with In. Specifically, electrolytic plating was applied to steel balls (1.00C-0.50Si-0.6Mn, Hv800) having an average particle diameter of 30 μm, 100 μm, and 500 μm, and In was coated with a thickness of about 10 μm.

  The other conditions are the same as in the first embodiment. In addition, Test No. The 16 test materials were not subjected to FPP treatment. In addition, Test No. About 17 test materials, In plating was given instead of FPP processing.

  Test No. For each of the test materials 1 to 17, the surface structure was analyzed and the friction characteristics were evaluated in the same manner as in Example 1. The results are summarized in Table 3.

  With reference to the results in Table 3, the test No. 1 satisfying the provisions of the present invention. In Nos. 1 to 13, the initial friction was 0.20 or less and the low friction durability was 15 minutes or more, which resulted in excellent sliding characteristics. On the other hand, the surface temperature during FPP treatment is too low. In No. 14, a dispersion layer was not formed in the substrate, resulting in poor low friction durability. In addition, the surface temperature is too high. In No. 15, the alloy layer and the metal layer were oxidized to oxides, resulting in poor friction characteristics. Furthermore, test No. which did not implement FPP processing. 16, the initial wear coefficient was inferior. And test No. with In plating on the surface. In No. 17, since the dispersion layer was not present in the substrate, the low friction durability was inferior.

  Of the above, two types of JIS standard equivalent products were used as test materials, and the same investigation as in Examples 1 and 2 was further conducted. However, in this example, test no. 1 and no. In No. 2, metal particles subjected to spraying in the FPP treatment were mixed with a steel ball coated with Sn and a steel ball coated with Bi at a mass ratio of 1: 1. In addition, Test No. In No. 3, the metal fine particles subjected to injection in the FPP treatment were mixed with steel balls coated with Bi and steel balls coated with In at a mass cost of 1: 1.

  Furthermore, test no. In No. 4, the metal fine particles subjected to injection in the FPP treatment were mixed with a steel ball coated with Sn and a steel ball coated with In at a mass ratio of 1: 1. And test no. 5, the mass ratio of 1: 1: 1 between the metal particles subjected to injection in the FPP treatment and the steel balls coated with Sn, the steel balls coated with Bi, and the steel balls coated with In. What was mixed with was used. The other conditions are the same as in Examples 1-3.

  Test No. About the test materials of 1-5, the surface structure was analyzed and the friction characteristics were evaluated by the same method as in Examples 1-3. The results are summarized in Table 4. In addition, Test No. The alloy layers 1 to 5 were all alloys composed of Fe and two or three selected from Sn, Bi, and In. In addition, the layer corresponding to the metal layer was a mixture of two or three selected from Sn, Bi and In, and was not necessarily mutually dissolved.

  With reference to the results in Table 4, the test No. 1 satisfying the provisions of the present invention. In Nos. 1 to 5, the initial friction was 0.20 or less and the durability of low friction was 15 minutes or more, resulting in excellent sliding characteristics.

  According to the present invention, it is possible to obtain a sliding member that is excellent in sliding characteristics and that maintains its state for a long time. Therefore, the sliding member according to the present invention can be suitably used as a sliding member used in transport machines such as automobiles and ships, general industrial machines, and the like.

1. Substrate 1a. Metal particles 1b. 1. Dispersion layer 2. Alloy layer Metal layer 10. Sliding member 11. Metal fine particles

Claims (7)

A base material made of steel, and an alloy layer formed on the surface of the base material,
The surface layer portion of the base material has a diameter of 0.01 μm to 2.0 mm, and has a number density of 50.0 / cm ² or more of metal particles including one or more selected from Sn, Bi, and In. There is a dispersion layer to disperse,
The thickness of the dispersion layer is 20.0 to 2000 μm,
The alloy layer includes at least one selected from Sn, Bi and In and Fe, and the total content of Sn, Bi and In is 10.0 to 75.0% in mass%, And the thickness is 3.0 to 100 nm,
Sliding member. Further comprising a metal layer formed on the surface of the alloy layer and made of one or more selected from Sn, Bi and In,
The sliding member according to claim 1. The contents of Sn, Bi, and In in the thickness center part of the base material are all mass% and 0.01% or less.
The sliding member according to claim 1 or 2. A method for producing the sliding member according to any one of claims 1 to 3,
Heating a surface of a base material made of steel to a temperature range of 300 to 800 ° C .;
A peening step of peening metal fine particles containing one or more selected from Sn, Bi and In on the heated surface.
Manufacturing method of sliding member. The metal fine particles have an average particle size of 30 to 500 μm.
The manufacturing method of the sliding member of Claim 4. In the metal fine particles, the surface of fine particles made of steel is coated with one or more selected from Sn, Bi and In.
The manufacturing method of the sliding member of Claim 4 or Claim 5. In the heating step, the surface is heated by high frequency induction heating.
The manufacturing method of the sliding member in any one of Claim 4-6.

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