effect of processing parameters on the morphology of α-phase in ti-6al-4v alloy during the two-step hot deformation

The morphology of the alpha;-phase in titanium alloys considerably affected their physical and mechanical properties. in this research, the effect of applied strain and inter-pass times on the morphology of the alpha;-phase was studied in the two-step hot deformation process. hot compression tests were performed at 900 ordm;c and 0.001 s-1 while the strains in the first and second passes were set as (first cycle: 0.6 and 0.3) and (second cycle: 0.3 and 0.6) respectively, with various inter-pass times. the work softening parameter obtained from the stress-strain curves showed that the proper time for globularization of alpha;-layers for the first pass strain of 0.6 was 240 s and for the second strain of 0.3 it was 240 and 300 s. microstructure results indicated that the first pass strain of 0.3 and the inter-pass time of 240 s were the optimum conditions for globularization of alpha; layers.