Influence of SURFACE PROCESSING METHOD on FRICTION JOINT restored by GAS-flame spraying ON THEIR TRIBOLOGICAL PROPERTIES
The dependence of friction coefficient in mating parts designed the work of friction couple «gear pump shaft - sleeve» is investigated for new parts and for restored by the method of gas-flame spraying. Samples No. 1 were made from carbon steel + tin bronze, samples No. 2 were made from carbon steel with gas-flame sprayed coating from NiCrBSi self-fluxing alloy + tin bronze. The surface of the samples was mechanically treated to a certain roughness using fine turning (Ra=0.4 microns), fine grinding (Ra=0.25 microns), ultra-fine grinding (Ra=0.16 microns), and polishing (Ra=0.08 microns). According to the results of studies, the samples with sprayed coatings have better antifriction properties than samples without coatings. Thus, the obtained values of friction coefficients with the same mechanical treatment in samples No. 2 are lower by 1.5-2 times than in samples No. 1. It is also established that polishing in these friction couples is insufficient because it leads to an increase in the friction coefficient, and as a consequence to a decrease in the performance of mating parts.