Effect of the surface adsorbate of SiC particles on fabrication and mechanical property of aluminum matrix composite

Abstract

SiCp/Al composites were prepared by pressureless infiltration using domestic abrasive grade SiC particles with average diameters in the range of 60-80μm. Ultrasonic cleaning method was used to investigate the effect of the surface adsorbate of SiC particles on the infiltration process and mechanical property of the SiCp/Al composite. The results show that all types of the studied SiC particles are adhered by low mass fractions of the adsorbate(μm)and,in certain cases,low fraction of carbon. That surface adsorbate has a negative effect on the wettability between SiC particles and molten alloy,resulting in the reduced density and mechanical property of the infiltrated SiCp/Al composite. Ultrasonic cleaning process can effectively wipe off the adsorbate,and,by using the cleaned SiC particles,the success rate of the infiltration can be raised from 25% to 100%. Correspondingly, the flexure strength and elasticity modulus of the composites are improved from 320MPa to 390MPa and from 203GPa to 232GPa, respectively.

Keywords

• silicon carbide
• adsorbate
• ultrasonic cleaning
• mechanical property