JPS61201788A - Wear resistant member - Google Patents

Abstract

PURPOSE:To reduce remarkably the adhesion wear of a wear resistant member made of a wear resistant material contg. hard particles dispersed in the metallic matrix by projecting part of the hard particles from the surface of the matrix. CONSTITUTION:A wear resistant member is made of a wear resistant material contg. hard particles of 1-100mum particle size dispersed in the metallic matrix. At this time, the surface of the member has hard particles projected from the surface of the matrix by 0.2-5mum. The hard particles are projected from the surface of the matrix by lapping the surface of the member with abrasive grains which are harder than the matrix metal and softer than the hard particles or by chemically leaching out the matrix metal.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a wear-resistant member made of a material in which hard particles are dispersed in a metal matrix, and particularly relates to a wear-resistant member made of a material in which hard particles are dispersed in a metal matrix. The present invention relates to a wear-resistant member.

[Conventional technology]

Wear-resistant members that are generally used while sliding in contact with or striking a mating member are widely used in various internal combustion engines as well as other machines and devices. Items that are used while moving include cams and rocker arm tips or rollers, items that are used while hitting are pulp and valve seats, and items that are used while sliding and hitting are cams and tappets. These members are claimed to have the characteristic that they do not wear out themselves, and at the same time do not wear out the mating members.

Conventionally, cast materials or sintered materials in which hard particles are dispersed in a metal matrix have been used as wear-resistant materials for this type of machine parts, and the matrix metal may be iron, aluminum, copper, or any of these. An alloy consisting of a metallic element and another element is used, while as hard particles, for example, carbides, nitrides, carbonitrides, oxides, borides and various intermetallic compounds of metallic or nonmetallic elements are used. ing.

[Problem that the invention seeks to solve]

The above-mentioned hard particles are harder than the matrix metal and play a role in imparting wear resistance to cast materials and sintered materials, but if these hard particles are chosen to be too hard.

Depending on the mating material, abrasive wear may occur and scrape off the mating material, so it is necessary to select an appropriate combination of hard particles for the mating material, but even if the appropriate hard particles are selected, wear still occurs. However, one type of wear is corrosive wear due to the operating environment, and the other type of wear is adhesive wear caused by metal adhesion to the mating material. Of these, the former type of corrosive wear can be prevented by selecting lubricating oils with anti-rust properties and material compositions with high corrosion resistance, but the latter type of adhesive wear cannot be completely prevented. This adhesive wear is particularly difficult to develop between similar metals or metals that are easily alloyed, and when it becomes severe, seizure may occur.

[Means for solving problems]

Therefore, the present inventors have conducted various studies to reduce the above-mentioned adhesive wear on wear-resistant members and extend their lifespan. As a result, the inventors have found that this adhesion is more likely to occur on the surface of the metal matrix than on the hard particle portion. Therefore, if hard particles that protrude beyond the metal matrix surface are formed on the surface of the component in advance, the area of direct contact between the mating component surface and the matrix surface will be reduced, thereby reducing adhesive wear. I found out.

This invention was made based on the above findings, and consists of a wear-resistant member made of a wear-resistant material in which hard particles are dispersed in a metal matrix (2, the member surface is The present invention provides the above-mentioned wear-resistant member having excellent seizure resistance, which is characterized by having hard particles protruding by 0.2 to 5 μm from the surface of the metal matrix.

The matrix metals conveniently used in this invention include, regardless of whether the wear-resistant material is a cast material or a sintered material,
For example, iron or iron alloys, copper or copper alloys, aluminum or aluminum alloys, cobalt or cobalt alloys are used, and the hard particles dispersed in these matrixes are usually Fe5C having a particle size of 1 to 100 μm.
, (Crepe)*sCa.

NbC, VC, TiN, AtN, Al2O,r
Y., O., Fego.

CuAt, etc. are used in this invention.

Of course, the matrix metal, the hard particles, and their particle sizes are not limited to those mentioned above.

In this invention, if the protruding amount of the hard particles protruding from the matrix surface is less than 0.2 μm, the desired improvement in adhesive wear resistance will not be seen because the mating member surface and the matrix surface will easily come into contact with each other. On the other hand, if it exceeds 5 μm, abrasive wear due to protruding hard particles becomes significant (-
Since hard particles that are partially embedded on the surface of one member may fall off from the surface, in this invention, the amount of protrusion of the hard particles is limited to 0.2 to 5 μm.

To make hard particles protrude from the matrix surface as described above,
A predetermined portion of the surface of a wear-resistant member manufactured by a conventional method is made harder than, for example, the parent metal.

In addition, methods such as lapping with soft abrasive grains rather than hard particles or chemically eluting the matrix metal are used.

[Examples and effects based on the examples]

Next, the invention will be explained with reference to examples.

Example 1 First, Cr: 4t4, Nb: 0.1
% + Mo: 0.1%.

Mn: 0.54, 0.2%, Fe
: The remaining (the above weight %, the same shall apply hereinafter unless otherwise specified) in the parent phase (=, particle size: 3 to 70 μm, MvsCa type carbide and MC type carbide having a total of about 3
0 volume coefficient dispersed iron-based sintered material (hereinafter referred to as 1 person) Cr: 4 '11 W: 0.2 clb *
Mo: 0.1 tlp*V: 0.1%
* to 0.2'1 *Fe: MosCa with particle size: 1 to 30 μm in parent phase metal with remaining composition
, a melting high-speed steel (hereinafter referred to as B material) in which NLC and MC type carbides are dispersed with a total volume coefficient of about 20, and Cr
: 3% *Mo: 0.14 *W: 0.1
% +V: 0.1% +Co: 5%.

'pi: O82% * to 0.2% * Fe
:Remaining, in the matrix metal having the composition, particle size: 1 to 20
M, , C, , M, C and MC type carbides with μm and T
An iron-based sintered material (hereinafter referred to as C material) in which approximately 25 iN particles are dispersed in total is prepared, rocker arm chips are manufactured from these materials, and each rocker arm chip has its own pad surface. The one that is still polished,
After polishing, alumina puff polishing was applied.

Next, for these rocker arm chips, the protrusion amount of hard particles protruding from the matrix surface was measured using a surface roughness meter, and the rocker arm chips were
cc gasoline engine (built-in, engine speed: 1500r, p, m, e engine oil: 5A
E20. Oil temperature: 55-60°C.

Operating time: Under conditions of 200 hours, each of the four arm tips mentioned above was slid, and the amount of wear that occurred on the tip and the cam part of the chilled casting camshaft that was its counterpart was measured using a surface roughness meter. The results are shown in Table 1.

From the results in Table 1, it can be seen that when using the rocker arm tip of the present invention in which hard particles were protruded from the matrix surface by performing puff polishing after polishing, no It can be seen that the amount of wear on both the tip and the cam portion is smaller than that of the comparative tip.

Table 1 Example 2 First, Mo: 0.1% #Cr: 4 t6 a
An aged product of an iron-based sintered material in which MosCs and MsC type carbides having a particle size of 1 to 40 μm are dispersed in a matrix metal having a composition of Co: 5 Qk mFe: the remainder by a volumetric coefficient of about 20. Hereinafter referred to as D material) and B
An aluminum alloy sintered material (hereinafter referred to as Samples with dimensions of 10 x 110 x 40 were cut out from these materials and polished, and then one of the 110 x 40 sides was polished with Gromia AB7.

Next, these test pieces were subjected to a wear resistance test using a block-on-ring, that is, on the outer periphery of a mating member made of a cast iron (Fe12) disc with a diameter of 40 mm and a thickness of 15 mm.
The 1010 x 40 surface of each test piece was pressed with a load of 6 noodles for material D and 3KII for material E, and while supplying lubricating oil to the contact surfaces of both, the disk was rotated at a speed of 2000.
Rotate for 15 hours at r, p, m, and
A test was conducted in which the outer circumferential surface of the disk was slid on a 0x40 surface, and the amount of wear on each test piece and disk was investigated in the same manner as in Example 1. The results are shown in Table 2 below. From the results in Table 2, it can be seen that for both material D and material E, the amount of wear between the test piece of the present invention and the disk that was its counterpart was It can be seen that the amount of wear is smaller than that of the comparative test piece in which the particles did not protrude from the matrix surface and the disk that was its counterpart.

[Overall effect of the invention]

As is clear from the above description, according to the present invention, the adhesive wear of the wear-resistant member is significantly reduced. It is possible to prevent a wide range of seizures that have occurred in the past, and to prolong the life of these parts, which is an industrially beneficial effect.

Claims (1)

[Claims] In a wear-resistant member made of a wear-resistant material in which hard particles are dispersed in a metal matrix, the surface of the member has hard particles that protrude by 0.2 to 5 μm from the metal matrix surface. The above-mentioned wear-resistant member having excellent seizure resistance.