High strain rate superplasticity of SiC whisker reinforced pure aluminum composites
(State Key Laboratory of Metal Matrix Composites,ShanghaiJiaoTong University, Shanghai200030, P.R.China)
Abstract: A β-SiC whisker reinforced pure aluminum composites expected to exhibit high strain rate superplasticity has been successfully fabricated by a new processing route consisting of pressure infiltration, extrusion with a low extrusion ratio and rolling. The composites exhibite a total elongation of 220%~380% in the initial strain rates within 1.0×10-2~1.0×10-1s-1 and at 893~903 K. According to differential thermal analysis(DTA) and microstructure observation, it is concluded that an appropriately small amount of liquid phase is necessary to cause a good high strain rate superplasticity in aluminum matrix composites in addition to fine and uniform microstructure.
Key words: high strain rate; superplasticity; aluminum matrix composites; pressure infiltration