Synthesis and characterization of Al-SiO2 composites

Abstract

In this paper, aluminum matrix composites are successfully synthesized by melting of Al scrap at 850 oC. The reinforcementswere then added gradually for 10 minutes to the molten aluminum with different amounts weight ratios (10, and 20) wt.%of SiO2. Mixtures were stirred with 450 rpm for 10 minutes after the additions of SiO2. The mixture was poured into previouslyprepared sand mold. The uniaxial tensile, cupping, and biaxial tensile tests were conducted by Gant Universal test machine, andlocal designed biaxial tensile machine. Al-SiO2 composites presented good resistance to both uniaxial and biaxial tensile tests. It was observed that the ultimate tensile strength for Al- SiO2 composites with 0, 10, and 20 wt% of SiO2 were 25 MPa, 62 MPa,and 65 MPa and respectively. The Al- 20 % wt of SiO2 composite presents good resistance to biaxial tensile test, and both ofcomposites present a lower deformation ratio. The cupping results were promising for the composite with a ratio of 10 % wtit was deformed without failure until the depth d = 1.8 mm, whereas many cracks have been observed with 20 %wt of SiO2 atsmall forming depth. Experimental and a finite-element simulation for biaxial and cupping test gave very closed results.