Investigation of Microstructural Uniformity During Isothermal Forging of Ti-6Al-4V

The effect of strain on microstructural changes and the primary alpha (alpha(P)) volume fraction as well as the workability of Ti-6Al-4V are studied by isothermal compression of wedge-shaped specimens at the initial temperatures of 850, 900, and 950 A degrees C and platen velocities of 2.5, 25, and 250 mm/min in combination with finite element method. The results show that higher platen velocity leads to a lesser alpha(P) volume fraction at all of the temperatures. Higher temperature reduces the alpha(P) volume fraction, but increases the impact of strain and platen velocity on the microstructure through the specimen. A more uniform distribution of the primary alpha volume fraction can be achieved by decreasing the initial temperature and/or platen velocity. All of the specimens were free from any defects and can withstand a compression with the normalized Cockcroft-Latham damage value of 0.61.