MECHANICAL PROPERTIES OF IN-SITUFeAl-TiB2 INTERMETALLIC MATRIX COMPOSITES

Abstract

Intermetallic matrix composites reinforced with ceramic particles have received a great deal of attention. Iron aluminide is known to be a good material for the matrix in such composites. Two processes were used to fabricate FeAl - TiB 2 intermetallic matrix composites. One was liquid melt in-situ mixing, and the other was arc melting and suction casting processes. FeAl - TiB 2 IMCs obtained by two different methods were investigated to elucidate the influence of TiB 2 content. In both methods, the grain size in the FeAl alloy decreased with the presence of titanium diboride. The grain size of in-situ FeAl - TiB 2 IMCs became smaller than that of arc FeAl - TiB 2 IMCs. Significant increase in fracture stress and hardness was achieved in the composites. The in-situ process gives clean, contamination-free matrix/reinforcement interface which maintained good bonding causing high load bearing capability. This contributed to the increase in the mechanical properties of composites.