High strain rate superplasticity of TiC particulate reinforced 2014 aluminum alloy composites

Abstract

Abstract High strain rate superplasticity (HSRS) was studied in a 2014Al matrix composites fabricated by a PM route with TiC particulate volume fraction of 15 and 20%, and the superplastic deformation mechanism of the composite was discussed. TiC/2014Al alloy composites were found to exhibit HSRS within the processing and tension testing conditions employed herewith. The composites hot-rolled at 818–833 K show m value of about 0.3 in the strain rates more than 2×10 −2 s −1 and in the temperature of 773–853 K and, maximum total elongation of 320% at a strain rate of about 7×10 −1 s −1 and at 833 K. TEM observation revealed that TiC particles are dispersed uniformly along grain boundaries of 2014Al matrix and the average grain size is about 2–3 μm. Misorientation angles between grains are 29° and 55°. True activation energy, for deformation of TiC/2014 alloy composites is 300 kJ/mol. The high strain rate superplasticity of the TiC/2014Al alloy composites can be controlled probably by dislocation glide and climb-controlled grain boundary sliding (GBS).