Properties of SiC_p/6061-Al metal matrix composites prepared by infiltrating molten aluminum into ternary packing of SiC preforms

Abstract

SiC particles reinforced aluminum matrix composites (SiC p /Al) with SiC content of more than 60%, without particle segregation for mirror substrate applications, are prepared by using the improved process. The improved process contains sintering process design, preform quality traceability, and equipment designing. The maximum SiC volume fraction of 70.4% is obtained by optimizing the selection of the following proportion: 71.4% coarse, 7.1% medium, and 21.5% fine particles. The variation of SiC volume fraction is correlated with the percentage of fine particles by using regression analysis. The preforms with the compressive strength above 10.34 MPa are prepared by sintering at 1600 C for 2 h. Results showed that no defects in the scale of more than 10 mm are observed in the preforms. Due to the generation of a SiO 2 layer during the sintering process, the formation of Al 4 C 3 phase was inhibited. As the SiC particle volume fraction increased from 65.6% to 70.4%, the bending strength increased from 483.2 MPa to 585.2 MPa. The elastic modulus also increased from 174.2 GPa to 206.1 GPa, while the coefficient of thermal expansion between 50 C and 350 C decreased from 11.02 Â 10 À6 / C to 9.53 Â 10 À6 / C.

Influence of particle size distribution on properties of SiC particles reinforced aluminum matrix composites with high SiC particle content

“…At the same time, the porous structure of SiC preform also inhibits the thermal expansion of the matrix. 20 Therefore, the CTE curves of the composites show the very similar tendency in the thermal behavior as SiC particles.…”

Preparation of SiCp/Al composite–bismuthate glass material and its application in mirror blanks

“…The wetting property of the local region is very poor owing to the aggregation of ne particles. 22 The oxide lm in the local region may be very thin due to the incomplete inltration and the small interspacing between the ne particles. At the same time, the local region provides porous path that allows the molten glass to permeate.…”

Fabrication and Properties of Aluminium Matrix Hybrid Nanocomposites by Stir Casting Technique

“…Indeed, even through powder metallurgy is more confounded than casting procedures, it yields a superior interface between the fortification and grid combination and improves mechanical properties of the composite. Broad works have been completed to assess different ceramic particles as the support materials for AMMCs [6]. The composite's ductility is, however, deteriorated by aluminum re-enhanced by single ceramic parts because they have a tendency to crack when the matrix is high at loading conditions.…”