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

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).