Effect of Hot Rolling Deformation on Superplastic Deformation Behavior of TiN_P/2014Al Composite

Abstract

1.5 mm, 0.7 mm and 0.3 mm thicknesses TiNP/2014Al composite sheets were obtained by hot rolling deformation carried out on as-extruded TiNP/2014Al composite rod. The effect of hot rolling deformation on high strain rate superplastic deformation behavior of the composite was researched by tensile experiment, OM, and SEM. Results show that 0.7mm thickness TiNP/2014Al composite sheet can gain the maximum elongation of 351% at 818 K and 3.3×10-1 s-1, and the m value is 0.43. The optimum strain rate increases with decreasing thickness of the TiNP/2014Al composite sheets. Flow stress and work hardening ability show contrary change tendency to optimum strain rate. The 0.7 mm thickness TiNP/2014Al composite sheet has medium flow resistance stress and shows excellent stability of plastic flow. Fracture surfaces show that the main superplastic deformation mechanism of the TiNP/2014Al composite includes in grain boundary sliding. Subgrain boundary sliding maybe another superplastic deformation mechanism.