JP6030465B2 - Sliding member and manufacturing method thereof - Google Patents

Description

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

  For example, in a vacuum pump, a vane slides in a dry atmosphere. A carbon material is used for the sliding member that slides in such a dry atmosphere. Specifically, a sliding member is produced mainly by adding a binder to graphite powder and kneading, molding and firing them (for example, Patent Document 1). Since graphite powder has high self-lubricating property, damage and wear of the sliding member with which the sliding member contacts are suppressed.

JP-A-11-279413

  However, in general, a sliding member made of a carbon material is more easily worn than a sliding member. Therefore, it is necessary to replace the sliding member periodically, which increases the cost.

  An object of the present invention is to provide a sliding member with improved wear resistance and a method for manufacturing the same.

A sliding member according to a first invention includes a graphite base material containing graphite , a binder, and a lubricant, and spherical carbide particles dispersedly present in the graphite base material . The spherical carbide particles are obtained by firing a spherical resin powder. The residual carbon ratio of spherical carbide particles is 40% or more and 90% or less, and the ratio of the weight of the spherical resin powder to graphite is 0.042 or more and 0.36 or less, and graphite, lubricant, and spherical resin When the total amount of powder is 100 parts by weight, the amount of binder added is 30 parts by weight or more and 100 parts by weight or less, and the graphite base material is slidable with respect to the sliding surface of the sliding member. In a state where the sliding surface is pressed against a sliding surface having a surface and an arithmetic average roughness of a sliding member made of cast iron of FC200 being 0.04 or less at a pressure of 0.2 MPa, 8.1 m / Reduced by wear when slid at 100 s for 100 hours That the thickness of the sliding member is not more than 0.095 mm.

  In the sliding member, spherical carbide particles exist in a dispersed manner in a graphite base material containing graphite and a binder. Thereby, the wear resistance of the sliding member is improved.

The particle size of the spherical-shaped carbide particles may be 150μm or less the range of 1 [mu] m. In this case, the wear resistance of the sliding member is further improved.
A sliding member according to a second invention includes a graphite base material containing graphite and a binder, and spherical carbide particles dispersedly present in the graphite base material, and the spherical carbide particles are kneaded with graphite and a binder. It is a fired product of spherical resin powder in a state.
The particle size of the spherical carbide particles may be in the range of 1 μm to 150 μm. In this case, the wear resistance of the sliding member is further improved.

Black Namarimotozai may further comprise a lubricant. In this case, the wear resistance of the sliding member is further improved.

Sliding member has a slidable sliding surface with respect to the sliding surface of the sliding member, the arithmetic mean roughness of the sliding member made of cast iron FC200 is 0.04 or less to be When the sliding surface is pressed against the sliding surface at a pressure of 0.2 MPa and sliding at a speed of 8.1 m / s for 100 hours, the thickness of the sliding member that decreases due to wear is 0.095 mm or less. It may be. In this case, the wear resistance of the sliding surface of the sliding member is sufficiently improved.

The manufacturing method of the sliding member according to the third invention includes a step of producing a mixed base material by kneading a mixed powder containing graphite and spherical resin powder and a binder, and a step of forming the produced mixed base material When, at a firing temperature of spherical resin powder contained in the mixed base material molded it becomes globular carbide particles, in which obtain Bei and a step of firing the shaped mixture substrate.

  In the sliding member manufactured by this manufacturing method, spherical carbide particles exist in a dispersed manner in a graphite base material containing graphite and a binder. Thereby, the wear resistance of the sliding member is improved.

Spherical shaped resin powder is spherical phenol resin powder, the firing temperature in the step of firing may be of 700 ° C. or higher 1300 ° C. or less. In this case, the wear resistance of the sliding member is further improved.

Mixing substrate in the step of preparing a mixed Gomotozai may comprise 4 or more parts by weight of spherical resin powder the mixed powder 100 parts by weight. In this case, the wear resistance of the sliding member is sufficiently improved.

Mixing substrate in the step of preparing a mixed Gomotozai may include 25 parts by weight or less of spherical resin powder the mixed powder 100 parts by weight. In this case, the wear resistance of the sliding member is sufficiently improved.

The proportion by weight of spherical resin powder to graphite mixed powder in the step of preparing a mixed Gomotozai may be of 0.042 or more. In this case, the wear resistance of the sliding member is sufficiently improved.

The proportion by weight of spherical resin powder to graphite mixed powder in the step of preparing a mixed Gomotozai may be 0.36 or less. In this case, the wear resistance of the sliding member is sufficiently improved.

The proportion by weight of spherical resin powder to graphite mixed powder in the step of preparing a mixed Gomotozai may be of 0.065 or more. In this case, the wear resistance of the sliding member is more sufficiently improved.

The proportion by weight of spherical resin powder to graphite mixed powder in the step of preparing a mixed Gomotozai may be of 0.067 or less. In this case, the wear resistance of the sliding member is more sufficiently improved.

Mixed-powder may further comprise a lubricant. In this case, the wear resistance of the sliding member is improved.

  According to the present invention, the wear resistance of the sliding member is improved.

It is a schematic diagram for demonstrating a sliding member. It is a figure which shows the cross section of the sliding member of Example 1 observed with an optical microscope. It is a schematic diagram for demonstrating a sliding test.

  Of the two members that move relatively in contact with each other, one member is called a sliding member, and the other member is called a sliding member.

  Hereinafter, a sliding member according to an embodiment of the present invention will be described with reference to the drawings.

(1) Configuration In the present embodiment, the sliding member is a movable member, and the sliding member is a fixed member. For example, in a vane pump, the vane is a sliding member and the casing is a sliding member. The sliding member and the sliding member have surfaces that can slide in contact with each other (hereinafter, referred to as a sliding surface and a sliding surface, respectively).

  The sliding member according to the present embodiment is manufactured by adding spherical resin powder to graphite powder and kneading, molding and firing them. FIG. 1 is a schematic diagram for explaining a sliding member. As shown in FIG. 1, in the sliding member, spherical carbides P exist in a dispersed manner in a graphite base material B mainly composed of graphite and a binder. The spherical carbide P is preferably higher in hardness than other materials in the graphite base material B.

  The sliding member is made of, for example, cast iron, stainless steel, aluminum alloy, or chrome plating. The surface roughness (arithmetic mean roughness Ra; JIS B 0601-2001) of the sliding surface of the sliding member is, for example, 0.025 μm to 0.8 μm, and 0.025 μm to 0.2 μm. Is preferred.

(2) Manufacturing method An example of the manufacturing process of a sliding member is demonstrated. First, a mixed powder is prepared by adding a spherical resin powder and a lubricant to graphite powder, and a mixed base material is prepared by kneading the mixed powder and a binder while heating. The addition amount of the spherical resin powder is, for example, from 1 part by weight to 30 parts by weight, and preferably from 4 parts by weight to 25 parts by weight with respect to 100 parts by weight of the mixed powder. The particle size of the spherical resin powder is, for example, 1 μm or more and 150 μm or less, and preferably 5 μm or more and 100 μm or less. The average particle size of the spherical resin powder is preferably 10 μm or more and 30 μm or less.

  As the graphite powder, artificial graphite powder, natural graphite powder, scaly graphite powder, soot or the like can be used, and a plurality of these may be mixed and used. For example, artificial graphite powder (hereinafter referred to as artificial graphite powder A) having a true specific gravity of 2.1 or more and 2.2 or less and an average particle size of 20 μm or more and 40 μm or less, and a true specific gravity of 2.25 or more and an average particle size of Artificial graphite powder (hereinafter referred to as artificial graphite powder B) having a size of 20 μm or more and 40 μm or less is mixed and used. As the spherical resin powder, a resin material that is non-melting and remains as a spherical carbide even after firing is used. The residual carbon ratio of the resin material after firing is, for example, 40% or more and 90% or less, and preferably 60% or more and 70% or less. For example, as the resin powder, phenol resin, epoxy resin, unsaturated polyester resin, amino resin (for example, melanin resin or urea resin), styrene-divinylbenzene copolymer, polyimide resin, or the like can be used. A plurality of them may be mixed and used.

  As the binder, pitch, tar, thermosetting resin, or the like can be used, and a plurality of these may be mixed and used. The added amount of the binder is, for example, 30 parts by weight or more and 100 parts by weight or less, and preferably 50 parts by weight or more and 80 parts by weight or less with respect to 100 parts by weight of the mixed powder.

  The heating temperature at the time of kneading is, for example, not less than 100 degrees and not more than 300 degrees.

As the lubricant, talc (Mg ₃ Si ₄ O ₁₀ (OH) ₂ ), kaolin (Al ₂ O ₃ .2SiO ₂ .2H ₂ O), bentonite, or the like can be used. It may be used. The amount of the lubricant added is, for example, from 1 part by weight to 10 parts by weight and preferably from 2 parts by weight to 5 parts by weight with respect to 100 parts by weight of the mixed powder. When the mixed powder contains the lubricant, the friction between the sliding surface of the sliding member and the sliding surface of the sliding member can be reduced. Moreover, even if a carbon film adheres to the sliding surface of a to-be-slid member because mixed powder contains a lubricant, the carbon film can be scraped off by sliding of a sliding member.

  In addition, when the lubricity between the sliding surface of the sliding member and the sliding surface of the sliding member is ensured by the graphite powder and the spherical resin powder, the mixed powder does not include a lubricant. Good.

  Next, the mixed base material obtained by kneading is pulverized into granules by a pulverizer. The average particle diameter of the granular mixed base material after pulverization is preferably 10 μm or more and 100 μm or less. Subsequently, the pulverized granular mixed base material is molded and then fired. Thereby, spherical resin powder turns into a spherical carbide. The spherical carbide is mainly composed of carbon, and may include an intermediate product obtained by baking a resin. In this way, the sliding member is completed. Molding of the mixed base material may be, for example, molding using a mold or CIP (Cold Isostatic Pressing) molding. A calcination temperature is 500 degreeC or more and 1500 degrees C or less, for example, and it is preferable that they are 700 degreeC or more and 1300 degrees C or less.

(3) Effect In the sliding member according to the present embodiment, the spherical carbide powder is dispersedly contained in the graphite base material, so that the wear resistance of the sliding surface is improved. This is presumably because the spherical carbide powder present on the sliding surface makes point contact with the sliding surface of the sliding member, so that the friction coefficient is lowered.

  As will be described later, the ratio of the spherical resin powder in the mixed powder in the production process is preferably 4 parts by weight or more and 25 parts by weight or less. Moreover, it is preferable that the ratio of the weight of the spherical resin powder with respect to the graphite in the mixed powder in a manufacturing process is 0.042 or more and 0.36 or less. In these cases, the wear resistance of the sliding surface is sufficiently improved. For example, a sliding test in which a sliding surface of a sliding member is slid for 100 hours at a speed of 8.1 m / s while being pressed against a sliding surface of a sliding member made of cast iron with a load of 0.2 MPa. As a result, the thickness reduction amount is 0.095 mm or less.

  Moreover, it is preferable that the ratio of the weight of the spherical resin powder with respect to the graphite in the mixed powder in a manufacturing process is 0.065 or more and 0.067 or less. In this case, the wear resistance of the sliding surface is further improved sufficiently. For example, as a result of the above sliding test, the thickness reduction amount is 0.045 mm or less.

(4) Examples and Comparative Examples (4-1) Examples (4-1-1) Example 1
A total of 92 parts by weight of graphite powder composed of 82 parts by weight of artificial graphite powder A having a relatively small true specific gravity and 10 parts by weight of artificial graphite powder B having a true specific gravity larger than that of artificial graphite powder A, and 6 parts by weight of spherical phenol as spherical resin powder. 2 parts by weight of talc was added as a resin powder and a lubricant to prepare a mixed powder. Further, 75 parts by weight of a pitch was added as a binder to the mixed powder, and the mixed powder and the binder were kneaded while being heated at 250 ° C. The mixed base material obtained by kneading was pulverized into granules by a pulverizer. In this case, pulverization conditions such as the number of revolutions of the pulverizer and the pulverization time were adjusted so that the particle size of the mixed base material of 60% by weight or more and 70% by weight or less of the entire mixed base material was smaller than 63 μm.

  Thereafter, the mixed base material was formed into a substantially rectangular parallelepiped shape having a size of about 170 × 340 × 80 mm by molding at a pressure of 100 MPa, and fired at about 900 ° C. to obtain a sliding member.

(4-1-2) Example 2
A sliding member was produced in the same manner as in Example 1 except that the ratio of the artificial graphite powder A was 80 parts by weight and the ratio of the talc was 4 parts by weight.

(4-1-3) Example 3
The ratio of the artificial graphite powder A is 70 parts by weight, the ratio of the spherical phenol resin powder is 25 parts by weight, the ratio of talc is 5 parts by weight, and the artificial graphite powder B is not used. A sliding member was prepared.

(4-1-4) Example 4
A sliding member was prepared in the same manner as in Example 1 except that the proportion of the artificial graphite powder A was 84 parts by weight and the proportion of the spherical phenol resin powder was 4 parts by weight.

(4-1-5) Example 5
The proportion of artificial graphite powder A is 80 parts by weight, the proportion of artificial graphite powder B is 5 parts by weight, 5 parts by weight of natural graphite powder having a true specific gravity of 2.26 is added, and the proportion of talc is 4 parts by weight. Except for this point, a sliding member was produced in the same manner as in Example 1.

(4-2) Comparative Example (4-2-1) Comparative Example 1
4.5 parts by weight of talc is added to a total of 95.5 parts by weight of graphite powder consisting of 88 parts by weight of artificial graphite powder A and 7.5 parts by weight of natural graphite powder having a true specific gravity of 2.25. Prepared. Further, 55 parts by weight of pitch was added as a binder to the mixed powder. Then, the sliding member was obtained by knead | mixing, grind | pulverizing, shape | molding and baking the mixed powder and the binder similarly to Example 1.

(4-2-2) Comparative Example 2
A sliding member was prepared in the same manner as in Example 1 except that the proportion of the artificial graphite powder A was 80 parts by weight, the proportion of talc was 10 parts by weight, and the spherical phenol resin powder was not used.

(4-2-3) Comparative Example 3
A sliding member was prepared in the same manner as in Example 1 except that the proportion of artificial graphite powder A was 84 parts by weight, the proportion of talc was 6 parts by weight, and spherical phenol resin powder was not used.

(4-2-4) Comparative Example 4
The ratio of the artificial graphite powder A is 80 parts by weight, the ratio of the artificial graphite powder B is 15 parts by weight, the ratio of talc is 5 parts by weight, and the spherical phenol resin powder is not used. A sliding member was prepared.

(4-3) Evaluation Table 1 shows the ratio of graphite powder, spherical resin powder, talc and binder in Examples 1 to 5 and Comparative Examples 1 to 4, and the ratio of the weight of the spherical resin powder to the graphite powder (hereinafter, weight). As well as the bulk density and hardness (HSD) after firing.

  FIG. 2 is a view showing a cross section of the sliding member of Example 1 observed with an optical microscope. As shown in FIG. 2, in the sliding member of Example 1, the presence of a spherical fired body having a configuration different from that of the surrounding tissue was confirmed. Moreover, when the cross section of the sliding member of other Examples 2-5 was observed with the optical microscope, presence of the spherical sintered body from which a structure differs from the surrounding structure | tissue was confirmed similarly to Example 1. FIG. This fired body corresponds to a spherical carbide obtained by firing a spherical resin powder.

  Further, the sliding members obtained in Examples 1 to 5 and Comparative Examples 1 to 4 were processed into a substantially rectangular parallelepiped shape of 12.5 × 20 × 32 mm, and a sliding surface of 20 × 5 mm was formed to further slide the sliding member. A sample for a dynamic test was prepared.

  A cast iron ring was used as the sliding member, and a sliding test of the manufactured sample was performed. FIG. 3 is a schematic diagram for explaining the sliding test. The outer diameter of the cast iron ring 1 in FIG. 3 was 90 mm, and the surface roughness Ra of the outer peripheral surface 1a, which was the sliding surface, was 0.04 μm before the sliding test. The prepared sample 2 is attached to the support member 3 so that the sliding surface 2 a contacts the outer peripheral surface of the cast iron ring 1. The support member 3 is provided so as to be swingable about the fulcrum 3a. A weight 4 is attached to the tip of the support member 3. The weight of the weight 4 is set so that the sliding surface 2a of the sample 2 is pressed against the outer peripheral surface 1a of the cast iron ring 1 with a load of 0.2 MPa.

  In this state, when the cast iron ring 1 is rotated, the sample 2 and the cast iron ring 1 are relatively slid. This test was performed at room temperature in the atmosphere, the peripheral speed of the cast iron ring 1 was 8.1 m / s, the rotation speed was 1730 rpm, and the sliding time was 100 hours.

  Table 2 shows the coefficient of friction of the sliding surface of the sample in the sliding test, the difference between the room temperature and the temperature of the sliding member in the sliding test (hereinafter referred to as the sliding temperature difference), and the sliding decreased due to wear. The thickness of the member (hereinafter referred to as thickness reduction amount) and the surface roughness Ra of the outer peripheral surface of the cast iron ring after the sliding test are shown.

  As shown in Table 2, in Examples 1 to 5, the thickness reduction amount was 0.033 mm or more and 0.095 mm or less. On the other hand, in Comparative Examples 1-4, the thickness reduction amount became 0.111 mm or more and 0.184 mm or less. Thereby, it turns out that thickness reduction amount is reduced compared with the case where the mixed powder in a manufacturing process does not contain a spherical resin powder because the mixed powder in a manufacturing process contains a spherical resin powder.

  Moreover, when the ratio of the spherical resin powder in the mixed powder in the production process was 4 parts by weight or more and 25 parts by weight or less, the thickness reduction amount was 0.095 mm or less. Thereby, it turns out that it is preferable that the ratio of the spherical resin powder in the mixed powder in a manufacturing process is 4 to 25 weight part.

  Moreover, when the ratio of the weight of the spherical resin powder to the graphite powder in the mixed powder in the manufacturing process was 0.042 or more and 0.36 or less, the thickness reduction amount was 0.095 mm or less. Thereby, it turns out that it is preferable that the ratio of the weight of the spherical resin powder with respect to the graphite powder in the mixed powder in a manufacturing process is 0.042 or more and 0.36 or less.

Furthermore, when the ratio of the weight of the spherical resin powder to the graphite powder in the mixed powder in the manufacturing process was 0.065 or more and 0.067 or less, the thickness reduction amount was 0.045 mm or less. Thereby, it turns out that it is more preferable that the ratio of the weight of the spherical resin powder with respect to the graphite powder in the mixed powder in a manufacturing process is 0.065 or more and 0.067 or less.
(5) Reference form
The sliding member according to the reference form includes a graphite base material containing graphite and a binder, and spherical carbide particles that are dispersed in the graphite group.
In the sliding member, spherical carbide particles exist in a dispersed manner in a graphite base material containing graphite and a binder. Thereby, the wear resistance of the sliding member is improved.
The particle size of the spherical carbide particles may be in the range of 1 μm to 150 μm. In this case, the wear resistance of the sliding member is further improved.
The graphite substrate may further contain a lubricant. In this case, the wear resistance of the sliding member is further improved.
The sliding member has a sliding surface slidable with respect to the sliding surface of the sliding member, and the sliding member made of FC200 cast iron has an arithmetic average roughness of 0.04 or less. When the sliding surface is pressed against the sliding surface at a pressure of 0.2 MPa and sliding at a speed of 8.1 m / s for 100 hours, the thickness of the sliding member that decreases due to wear is 0.095 mm or less. It may be. In this case, the wear resistance of the sliding surface of the sliding member is sufficiently improved.
The manufacturing method of the sliding member according to the reference form includes a step of producing a mixed base material by kneading a mixed powder containing graphite and spherical resin powder and a binder, a step of forming the produced mixed base material, And the step of firing the molded mixed base material, and the spherical resin powder becomes spherical carbide particles at the firing temperature in the step of firing.
In the sliding member manufactured by this manufacturing method, spherical carbide particles exist in a dispersed manner in a graphite base material containing graphite and a binder. Thereby, the wear resistance of the sliding member is improved.
The spherical resin powder is a spherical phenol resin powder, and the firing temperature in the firing step may be 700 ° C. or higher and 1300 ° C. or lower. In this case, the wear resistance of the sliding member is further improved.
The mixed base material in the step of preparing the mixed base material may include 4 parts by weight or more of spherical resin powder with respect to 100 parts by weight of the mixed powder. In this case, the wear resistance of the sliding member is sufficiently improved.
The mixed base material in the step of preparing the mixed base material may include 25 parts by weight or less of spherical resin powder with respect to 100 parts by weight of the mixed powder. In this case, the wear resistance of the sliding member is sufficiently improved.
0.042 or more may be sufficient as the ratio of the weight of the spherical resin powder with respect to the graphite in the mixed powder in the process of producing a mixed base material. In this case, the wear resistance of the sliding member is sufficiently improved.
The ratio of the weight of the spherical resin powder to the graphite in the mixed powder in the step of producing the mixed base material may be 0.36 or less. In this case, the wear resistance of the sliding member is sufficiently improved.
0.065 or more may be sufficient as the ratio of the weight of the spherical resin powder with respect to the graphite in the mixed powder in the process of producing a mixed base material. In this case, the wear resistance of the sliding member is more sufficiently improved.
0.067 or less may be sufficient as the ratio of the weight of the spherical resin powder with respect to the graphite in the mixed powder in the process of producing a mixed base material. In this case, the wear resistance of the sliding member is more sufficiently improved.
The mixed powder may further contain a lubricant. In this case, the wear resistance of the sliding member is improved.

  The present invention can be effectively used for various sliding members.

B Graphite base material P Spherical carbide

Claims (15)

A graphite substrate comprising graphite , a binder and a lubricant ;
Comprising spherical carbide particles dispersedly present in the graphite substrate ,
The spherical carbide particles are a fired product of spherical resin powder, and the residual carbon ratio of the spherical carbide particles is 40% or more and 90% or less,
The ratio of the weight of the spherical resin powder to the graphite is 0.042 or more and 0.36 or less,
The amount of the binder added when the graphite, the lubricant, and the spherical resin powder as a whole are 100 parts by weight is 30 parts by weight or more and 100 parts by weight or less,
The graphite substrate has a sliding surface that can slide relative to the sliding surface of the sliding member,
The sliding member made of cast iron of FC200 has an arithmetic average roughness of 0.04 or less and the sliding surface is pressed with a pressure of 0.2 MPa at a speed of 8.1 m / s. A sliding member having a thickness of 0.095 mm or less, which is reduced by wear when sliding for 100 hours . The sliding member according to claim 1, wherein the spherical carbide particles have a particle size in a range of 1 μm to 150 μm. A graphite substrate containing graphite and a binder;
  Comprising spherical carbide particles dispersedly present in the graphite substrate,
  The spherical carbide particles are sliding members, which are a fired product of spherical resin powder in a state of being kneaded with the graphite and the binder. The sliding member according to claim 3, wherein the spherical carbide particles have a particle size in a range of 1 μm to 150 μm. The sliding member according to claim 3 or 4 , wherein the graphite base material further includes a lubricant. Having a sliding surface slidable relative to the sliding surface of the sliding member;
The sliding member made of cast iron of FC200 has an arithmetic average roughness of 0.04 or less and the sliding surface is pressed with a pressure of 0.2 MPa at a speed of 8.1 m / s. The sliding member according to any one of claims 3 to 5 , wherein the thickness of the sliding member that decreases due to wear when sliding for 100 hours is 0.095 mm or less. A step of producing a mixed base material by kneading a mixed powder containing graphite and spherical resin powder and a binder;
Forming the prepared mixed substrate; and
At a firing temperature of spherical resin powder contained in the molded mixed substrate is spherical carbide particles, El Bei and a step of firing the shaped mixture substrate, a manufacturing method of a sliding member. The method for manufacturing a sliding member according to claim 7 , wherein the spherical resin powder is a spherical phenol resin powder, and a firing temperature in the firing step is 700 ° C or higher and 1300 ° C or lower. The method for manufacturing a sliding member according to claim 7 or 8 , wherein the mixed base material in the step of preparing the mixed base material includes 4 parts by weight or more of the spherical resin powder with respect to 100 parts by weight of the mixed powder. The method for manufacturing a sliding member according to claim 9 , wherein the mixed base material in the step of preparing the mixed base material includes 25 parts by weight or less of the spherical resin powder with respect to 100 parts by weight of the mixed powder. The method for manufacturing a sliding member according to claim 7 or 8 , wherein a ratio of the weight of the spherical resin powder to the graphite in the mixed powder in the step of preparing the mixed base material is 0.042 or more. The method for manufacturing a sliding member according to claim 11 , wherein a ratio of the weight of the spherical resin powder to the graphite in the mixed powder in the step of preparing the mixed base material is 0.36 or less. The method for manufacturing a sliding member according to claim 11 or 12 , wherein a ratio of the weight of the spherical resin powder to the graphite in the mixed powder in the step of preparing the mixed base material is 0.065 or more. The method for manufacturing a sliding member according to claim 13 , wherein a ratio of the weight of the spherical resin powder to the graphite in the mixed powder in the step of preparing the mixed base material is 0.067 or less. The said mixed powder is a manufacturing method of the sliding member in any one of Claims 7-14 which further contains a lubricant.

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