Mechanical and microstructural variations in ECAP of Ti-6Al-4V alloy with equiaxed microstructure

The aim of this study is to investigate mechanical and microstructural variations of Ti-6Al-4V acquired through various equal channel angular pressing (ECAP) cycles. The ECAP of Ti-6Al-4V alloy with the first equiaxed microstructure was carried out by an isothermal warm and isothermal die method. ECA pressing carried out on cylindrical samples at 650 degrees C. Mechanical and microstructural investigations were performed concerning Ti-6Al-4V in the first state after 2, 4, and 8 passes. Optical microscopy (OM) investigation shows that alpha grain size increases and beta grain size decreases with the pass numbers increasing. Beta phase content initially decreases in the first two ECAP passes. The results show that more equiaxed alpha grains are achieved after four ECAP passes. Results of X-ray diffraction (XRD) analysis show that crystallite size decreases with the number of passes increasing. After two ECAP passes, a vivid increase in mechanical strength is observed; however, the increment dramatically slows down by the increasing number of passes.

Automated summary

The aim of this study was to investigate the mechanical and microstructural variations of Ti-6Al-4V alloy through different ECAP cycles. The results revealed changes in grain size and phase content after ECAP pressing, and a significant increase in mechanical strength initially followed by a decrease in the increment.