Effect of pouring temperature on cast Al/SiCp and Al/TiB2 metal matrix composites

The effect of pouring temperatures of an (Al/SiCp) and (Al/TiB ) metal matrix composites (MMCs) synthesized using stir casting method were studied. The Al/SiCp composite were fabricated by mixing of 6wt.% of SiCp into cast A356 aluminium alloy melt and poured at diverse pouring temperatures (730 C, 750 C and 770 C). The Al/TiB MMCs were obtained by melting A356 aluminium alloy and mixing of KBF and K TiF precursor salts whose stoichiometric ratio composition corresponds to 6wt.% of TiB reinforcement and other parameters were constant (stirring speed 300 RPM and holding time 30 minutes). The composite melt was poured into the permanent mould with varied pouring temperatures (800 C, 820 C and 840 C). Coarser and homogenous SiC particles were presented in the Al/SiCp MMCs, whereas, finer and uniformly distributed TiB particles were appeared at the MMCs of Al/TiB . The mechanical properties viz. tensile strength, fracture toughness and hardness of Al/SiCp and Al/TiB MMCs were experimentally determined as per the ASTM standards and compared. Higher tensile and fracture strength were occurred at the MMCs of Al/TiB as compared to Al/SiCp MMCs and base alloy of aluminium as well. Maximum hardness was attained at the pouring temperatures of 820 C and 750 C in the MMCs of Al/ TiB and Al/SiCp, respectively.