Mechanical properties and fracture behavior of SiCw reinforced Al–12Ti alloy prepared by bechanical alloying technique

Abstract

Room and elevated temperature mechanical properties and thermal stability of SiC whisker (SiCw) reinforced Al–12Ti alloys fabricated by mechanical alloying were investigated. The results show that SiCw/Al–12Ti composites manifest higher room and elevated temperature strength and Young's modulus and specific strength and stiffness with increasing SiCw content, which can be attributed to the combined strengthening from Al 3Ti particles and SiC whiskers. The combined strengthening effect is especially good for lower SiCw content. The thermal stability of the composites at 550°C worsens compared to that of the unreinforced MA Al–12Ti alloy. The in situ crack propagation observation under SEM shows that the fracture behavior of SiCw/Al–12Ti composites substantially differs from that of the MA Al–12Ti alloy, but changes slightly with increasing SiCw content. The strengthening mechanisms of the composites are also discussed.