Influence of FSP process modification on selected properties of Al-Si-Cu/SiCp composite surface layer
Michał Stawiarz, Paweł Kurtyka, Natalia Rylko, Simon Gluzman
Quarterly No. 4, 2019 pages 161-168
DOI:
keywords: aluminium matrix composite, structure analysis, mechanical properties, tribological behaviour, ball-on-disc method
abstract The paper presents the results of mechanical and tribological tests conducted on the surface of Al-Si-Cu/SiCp composite reinforced with SiC particles and modified by friction stir processing (FSP) with different parameters. Changes in the distribution of the reinforcement particles on the modified surface of the composite were calculated and analyzed using a new analytical RVE theory with Eisenstein-Rayleigh-Mityushev sums (ERM-sum) (see the definitions below), and PointSel software. The Vickers hardness test with a 1 N load and the ball-on-disc method were used to test the material properties. A high degree of homogenization of the tested material was observed as a result of its modification, as evidenced by an approximately 4-fold reduction in the size of representative volume element (RVE) cells. The size of the RVE cell decreased almost four times for the material after modification, which indicates the high level of homogenization of the tested material. Moreover, we observed a reduction by order of magnitude of the anisotropy coefficient of the distribution of the reinforcing phase particles after the modification process. A 30% increase in the Vickers microhardness of the representative areas was obtained for the modified composites. After the FSP modification process the friction coefficient increases by 40%, and almost 25% decrease in the specific wear rate is observed. Both effects are attributed to the achieved homogenization of particle distribution and reduction of particle size up to 38%.