RU2528542C2 - Antifriction powder composite - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to powder metallurgy, particularly, to antifriction materials for gas-thermal evaporation. It can be used in machine building for production, updating and repair of slider bearings. Proposed antifriction material contains 65-80 wt % of "Б83" babbitt powder and 20-35 wt % of "БрО10Ф1" or "БрО10" grade bronze powder.

EFFECT: lower friction and wear at normal durability.

2 dwg, 3 tbl

Description

The invention relates to the fields of powder metallurgy and thermal spraying, in particular to sintered and sprayed anti-friction materials, and can be used in mechanical engineering in the production, modernization and repair of plain bearings.

Materials based on tin and copper are widely used for the manufacture of an antifriction layer in sliding bearings. In Russia, such alloys are the tin babbits B88, B83 GOST 1320-74 [1] and the tin bronzes BrO10F1, BrO10C10 GOST 613-79 [2] and BrO4TS4S2.5 GOST 5017-2006.

The composition and properties of tin and lead babbits are also regulated by the international organization for standardization (ISO) and many national associations, for example ASTM (USA), DIN (Germany), JIS (Japan), BSI (Great Britain) and others. The grades and composition of tin babbits and bronzes, the most widely used in Russia and the world as antifriction material for sliding bearings, are given in Table 1.

Table 1 The chemical composition of tin babbits and tin bronzes Mark Standard Basic chem. e-mail, wt.%. average Sn Sb Cu Pb Zn P Babbits SnSbl2Cu6Pb ISO 4383-91 80.0 12.0 6.0 2.0 - - TEGO V738 DIN EN 10204-3.1 81.0 12.0 5,0 - - - B83 GOST 1320-74 83.0 11.0 6.0 - - - Wj-2 JIS H 5401-58 84.0 9.0 5.5 - - - B88 GOST 1320-74 88.0 7.5 3.0 - - - TEGO HM07 DIN EN 10204-3.1

SnSb8Cu4 ISO 4383-91 89.0 7.5 3,5 - - - Grade 2, ASTMB23, Nickel genuine QQ-T390A Bronze BrO10F1 GOST 613-79 10.0 - 89.0 - - 1,0 GCuSnlO DIN 1705 10.0 - 90.0 - - - Br012 TU 27.4-25917641-001-2002 12.0 - 88.0 - - - BrO10S10 GOST 613-79 10.0 - 80.5 9.5 - - Phosphor bronze SAE 64 10.0 - 79.0 10.0 - 1,0 BrO4Ts4S2.5 GOST 5017-2006 4.0 - 89.0 2,5 4.0 0,03

In the works [3 ... 5 and many others. et al.] the following is shown.

1. It is advisable to use babbit anti-friction materials in sliding friction units with a low specific load and high sliding speeds.

2. Copper-based alloys have higher strength properties (compared to babbits), but they do not always have good tribotechnical characteristics.

3. In the manufacture and repair of plain bearings with a babbit or bronze antifriction layer, it is advisable to use thermal spraying, as this provides high wear resistance and a low coefficient of friction of the coating.

Due to the importance of the problem of improving anti-friction alloys, their technological and mechanical properties, the development of these materials is ongoing. For example, in order to increase the antifriction and physical and mechanical properties, a sintered complex-alloyed powder antifriction powder based on copper is proposed, containing the following components, wt.%: Tin 9-11, lead 9-11, molybdenum disulfide 1-2, self-fluxing chromium-nickel alloy PR-Н65Х25СЗРЗ 1-3, copper - the rest (RF patent No. 94038081, C22C 13/02, prior. 31.08.94). The material is recommended for the manufacture of sliding bearings of heavily loaded sliding friction units. However, this alloy contains a large number of components and phases, whose role in the formation of its properties is unclear.

In the patent of the Russian Federation No. 205076, C22C 13/02, prior. 12.1194 an alloy based on tin was proposed, containing components in wt.%: Antimony 6-15, copper 3-10, zinc 0.1-2 and silver 0.05-1, which is an unusual situation, extraordinary on all sides.

As a prototype, it is advisable to consider RF patent No. 2162174 (F16C 33/04, 33/12, prior. 02.23.99) for the composition of an antifriction alloy containing the following components in the ratio: B83 babbit (85-90 wt.%), Molybdenum disulfide ( 15-10 wt.%.). The technical result - the coefficient of friction and wear of the material are reduced, however, the strength characteristics of this alloy will inevitably be reduced, and its increased hardness will lead to increased wear of the counterbody - shaft in comparison with B83 babbit, which is not positive.

An object of the invention is to reduce the coefficient of friction, wear rate and cost of antifriction material while maintaining strength characteristics.

An anti-friction material manufactured by powder metallurgy or by thermal spraying of a mixture of powders of tin babbit grade B83 (65-80 wt.%) And tin bronze grade BrO10 (20-35 wt.%) Is proposed.

The choice of a mixture of powders of two standard alloys for creating a new antifriction material is due to the fact that at the initial stage of the presented studies, during tribological tests of tin bronzes BrO10 and BrO12 in cast, deformed and sprayed states, we observed the friction-mechanical transfer of these bronzes to a steel counterbody. The test of B83 babbit in the cast and sprayed states on the “bronzed”, thus, counterbody revealed a significant (2 or more times) decrease in the friction coefficient in comparison with the test results on the “clean” steel counterbody. This effect established by us is the basis for creating a mixture of powders.

In the proposed materials (see Fig. 1 which shows the structure of a plasma-sprayed coating of B83 babbitt powder 77 wt.% And BrO10F1 23 wt.% Bronze), the sprayed and sintered coatings come in contact with the steel surface of the counterbody mainly through relatively solid inclusions bronze. External friction ultimately ensures the formation on the bronze surface of a layer of copper-based film and its friction-mechanical transfer to the counterbody, fundamentally changing the friction conditions. The dissolution of protruding bronze particles and their pressing into a “soft” babbitt base under load leads to the formation of a new friction pair: babbitt — a bronze film on a steel counterbody.

A copper-based film is a semi-liquid body, therefore, has a low shear resistance and is unable to accumulate during dislocation deformations. Bronze particles act as “donors” supporting a layer of bronze film on the surface of the counterbody. In this case, friction is due to the complex of processes accompanying selective transfer [4], together with the friction features of the porous sprayed coating.

Considering the above, it can be argued that similar effects will occur in other coatings made from a mixture of tin babbits and bronzes (see Table 1), for example, from a mixture of SnSb8Cu4 babbit powders ISO 4383-91, or WJ-2 JIS H 5401- 58 (analogues of B83) with bronzes Br012 TU 27.4-25917641-001-2002, or GCuSn10, which do not differ significantly from the materials proposed and tested by us.

The decrease in the cost of antifriction plain bearings made of the proposed material is associated with a reduced content in the composition of an expensive and scarce component - tin babbitt powder - due to its partial replacement with cheaper bronze powder.

Preservation of the strength properties of the proposed anti-friction coating from a mixture of babbitt and bronze powders at the level of strength indicators of powder coatings made from the starting components is ensured by the good adhesion (fusibility) of tin babbitt and tin bronze.

The friction coefficient of the developed materials was determined on a laboratory computerized friction setup according to the finger-disk scheme under conditions of boundary lubrication with Tp-22 turbine oil [6]. The wear rate was determined by imprinting.

Typical results of comparative tests of materials from powders of tin babbit B83 and tin bronzes BrO10, BrO10F1 and their mixtures made by powder metallurgy and plasma spraying methods are presented in Tables 2, 3.

table 2 Coefficient of friction of coatings sintered from B83 babbit and BrO10 bronze powders Friction conditions The friction coefficient of the coating containing, wt.% B83 one hundred 88 77 72 66 56 - MPa ν, m / s BrO10 - 12 23 28 34 44 one hundred 2 3.3 0,023 0,032 0,032 0,028 0.012 0,028 0,022 13.0 0,023 0,023 0,053 0,067 0,041 0,042 0,033 6 3.3 0.024 0,028 0,040 0,043 0.018 0,037 - 13.0 0,025 0,034 - - - - -

Table 3 Friction coefficient and wear rate of coatings plasma-sprayed with B83 babbit and BrO10F1 bronze powders Friction conditions The friction coefficient of the coating containing, wt.% B83 one hundred 83 77 72 66 61 46 22 - ρ, MPa ν, m / s BrO10F1 - 17 23 28 34 39 54 78 one hundred 2 3.3 0.017 0.019 0.012 0.017 0.019 0.019 0,025 0,029 0,032 13.0 0.019 0,020 0.013 0,022 0,034 0,022 0,025 0,027 0,032 6 3.3 0.011 0.016 0.010 0.014 0.015 0.017 0.018 - - 13.0 0.011 0.015 0.010 0.019 0,022 0.024 0.018 - - Wear rate I, μm / km 3 3.3 0,073 0,033 - - - - 0.016

The results presented in Tables 2 and 3 show that sintered material containing 34 wt.% BrO10 bronze and 66 wt.% B83 babbitt, as well as plasma-sprayed material containing 23 wt.% BrO10F1 bronze and 77 wt.% B83 babbitt , have friction coefficients lower than those of sintered and sprayed materials from B83 babbit or BrO10, BrO10F1 bronzes. The best combination of the coefficient of friction and the wear rate over a wide load-speed range of friction conditions has a material plasma-sprayed with a mixture of B83 babbit powder (77 wt.%) And BrO10F1 bronze (23 wt.%). Figure 2 shows the characteristic dependences of the coefficient of friction on specific pressure for materials made from mixtures of babbitt and bronze powders with the specified composition, in comparison with sintered and plasma-sprayed materials from B83 babbitt and BrO10, BrO10F1 bronzes.

Materials in which the content of ingredients is outside the above limits have a higher coefficient of friction under the accepted test conditions. However, it is well known that the friction coefficient and wear rate of the same pair, depending on the friction conditions, can vary within wide limits [7], therefore, the required ratio of powders in the mixture for the manufacture of antifriction material is determined by the coating technology (powder metallurgy, thermal spraying) and the operating conditions of a particular sliding friction unit.

An analysis of the test results given in Tables 2, 3 and Fig. 2 indicates the promise of using a mixture of powders of babbit B83 (65-80 wt.%) And bronze BrO10F1 (BrO10) (20-35 wt.%) For the manufacture of antifriction coatings in plain bearings using powder metallurgy and plasma spraying methods. This provides a reduced coefficient of friction, wear and, as a result, increased efficiency and reliability of friction units.

The material of the proposed composition combines the positive operational properties of each of the starting components, namely, tin babbitt works well at high sliding speeds (for example, B83 up to 50 m / s), and tin bronze at elevated pressures in the friction zone (BrO10F1 up to 15 MPa). The advantage of the proposed material is also the simplicity of its production by sintering or spraying a mixture of powders of tin babbitt and tin bronze, widely distributed in Russia (PR-B83, PR-BrOF10-1) and abroad.

Sources of information taken into account when compiling the description

1. GOST 1320-74. Tin and lead babbits Technical specifications. [Text]. - Instead of GOST 1320-55 .; enter 1975.01.01 .; prov. 1984.06.29. - M .: Publishing house of standards. 2001 .-- 9 (10) p.: Ill.

2. GOST 613-79 (ISO 4383-91). Foundry tin bronzes. Stamps. [Text]. - Instead of GOST 613-65 .; enter 1980.01.01. - M .: Publishing house of standards. 2000 .-- 5 s.

3. Arzamasov B.N., Brostem V.A., Boucher N.A. et al. Structural materials: Handbook. - M.: Mechanical Engineering, 1990. - 688 p.

4. Garkunov D.N. Tribotechnology (wear and dryness): Textbook. 4th ed., Rev. and add. M.: Publishing House of the Moscow Art Academy, 2001. 616 p.

5. Khmelevskaya V. B., Volodin V. I., Khamzin P. M., Leontiev L. B. Principles of choosing antifriction material for plain bearings.

6. Ilyushin VV, The effect of the composition of the plasma coating “babbit-bronze” on the coefficient of friction [Text] / VV Ilyushin, B. A. Potehin, A. S. Khristolyubov // Mater. 10th scientific practical conf. Part 1. - SPb .: Publishing house of the Polytechnic. University, 2008. S.133-139.

7. Kragelsky I.V. Friction and wear. Ed. 2nd, perab. and add. M.: Mechanical Engineering, 1968.480 s.

Claims (1)

Powder anti-friction material for coating bearings, containing B83 brand babbitt powder, characterized in that it additionally contains BrO10F1 or BrO10 brand bronze powder in the following ratio, wt.%:
babbitt powder 65-80
20-35 bronze powder

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