Dry sliding wear behavior of SiC_P/QE22 magnesium alloy matrix composites

摘要

In present work, an attempt has been made to investigate the wear behavior of particle reinforced composites based on one of the proper magnesium alloys. The SiC_P/QE22 composites and QE22 unreinforced specimens were produced via the powder metallurgy route. The volume fractions of SiC particles with three different shapes, i.e. sharp, blocky and round, were selected in the range of 10-25 vol.%. The dry sliding tests were conducted on unreinforced matrix and SiC_P/QE22 composites using pin-on-disk apparatus, according to ASTM G99-95a standard. The applied loads were selected as 3, 5 and 20 N. The tests were carried out under sliding speeds of 0.5 and 1.2 m/s. In all tests, the sliding distances were chosen in the range of 750-3000 m. The worn pins surfaces and debries were examined using SEM. The EDX analysis was also performed on worn surfaces. According to results, the wear resistance of the matrix alloy could be increased by incorporation of SiC particles. However, in some cases, decrease of the wear resistance has been experienced. The wear resistance does not increase monotonicaily with increasing the particle content. The increase of sliding distance causes more weight loss at a constant rate. The application of higher loads induces more wear on specimens. The sliding velocity increment has same effect on wear behavior of specimens. The sharp shape reinforcing particles are more easily pull out and machined away from the composites with high particles content. According to observations, in various sliding test conditions, the abrasive, oxidation and delamination are mostly operated in combination.