한국주조공학회

The superplastic behavior ofwhisker reinforced alumin um alloy matrix composites fabricated by squeeze casting as one ofhig pressure routes was investigated. The preforms ofot-Si3N,, and [3-SiC whiskers without any binder as a reinforcement were used. The matrix materials were 2024 and 7075 aluminum alloys. For the purpose ofoptimum superplastic condition, respectively, the whiskers volume fraction, extrusion temperature, tensile test temperature and initial strain rate were changed. Fracture surface of tested specimens were observed by SEM.By the results, it became possible to produce superplastic composites by applying only a hot extrusion process to composites obtained by the squeeze casting. The superplastic composites developed arcot- Si3N4w/7075,ot Si3N4w/2024 and [3-SiCw/2024 systems at high strain rate.

High strain rate superplasticity, Aluminum alloy matrix composite, Squeeze casting,Si3N4 whisker, SiC whisker