Fabrication of aluminum matrix composites reinforced with nano- to micrometer-sized SiC particles

Abstract

ab s t r a c tIn this study, the hot extrusion process was applied to stir cast aluminum matrix-SiC composites in order to im-prove their microstructure and reduce cast part defects. SiC particles were ball milled with Cr, Cu, and Ti as three forms of carrier agents to improve SiC incorporation. Large brittle ceramic particles (average particle size: 80 μm) were fragmented during ball-milling to form nanoparticles in order to reduce the cost of composite manufactur-ing. The experimental results indicate that full conversion of coarse micron sized to nanoparticles, even after 36 h of ball milling, was not possible. Multi modal SiC particle size distributions which included SiC nanoparticles were produced after the milling process, leading to the incorporation of a size range of SiC particle sizes from about 50 nm to larger than 10 μm, into the molten A356 aluminum alloy. The particle size of the milled powders and the amount of released heat from the reaction between the carrier agent and molten aluminum are inferred as two crucial factors that affect the resultant part tensile properties and microhardness.

Influence of Titanium Diboride Particle Size on Structure and Mechanical Properties of an Al-Mg Alloy

“…It has been shown in [14] that the optimal size of titanium diboride particles is from 1 to 5 µm for their use as inoculants in aluminum alloys upon conventional cooling rates and corresponding levels of melt undercooling. At the same time, it is known that for dispersion hardening of aluminum alloys, involving the Orowan mechanism, it is necessary to use particles with size less than 500 nm, such as aluminum oxide [15,16], silicon carbide [17], etc. These fine non-metallic particles become an obstacle for the moving dislocations in aluminum upon its deformation [18].…”

Hot Deformation Behavior and Strain-Compensated Constitutive Equation of Nano-Sized SiC Particle-Reinforced Al-Si Matrix Composites

“…It is well known that SiCp/Al composites usually require secondary deformation, such as forging and hot rolling, before being employed in the industrial field because the properties of the composites can be significantly improved by hot deformation. In recent years, many scholars have performed numerous studies on the hot deformation behavior of a number of alloys and composites and developed corresponding constitutive equations [12][13][14][15][16][17]. For instance, Chen et al [12] constructed a constitutive equation for hybrid particle-reinforced aluminum matrix composites and found an activation energy of the composites of 269 kJ/mol.…”

Regulating Mechanical Properties of Al/SiC by Utilizing Different Ball Milling Speeds

“…SiC particulates are among the most used reinforcements to strengthen the aluminum matrix [9][10][11]. Nonetheless, the great degradation of some properties, such as ductility, in aluminum MMCs reinforced with SiC microparticles is a key challenge [12][13][14]. Tjong reported that the tendency of large ceramic particulates to be cracked during mechanical loading can result in lower ductility and premature failure [15].…”