Hot Processing of Powder Metallurgy and Wrought Ti-6Al-4V Alloy with Large Total Deformation: Physical Modeling and Verification by Rolling

Abstract

The influence of the total deformation amount on the microstructure and selected properties of Ti-6Al-4V alloy was determined in this study. Multi-axis compression tests on the MaxStrain module were performed to obtain large strains. Starting material for the research was obtained by the powder metallurgy (PM) route. Plastically processed cast alloy of the same chemical composition as PM alloy was also tested as reference material. The tests were performed with the cooling of samples between successive deformation stages, which allowed for the simulation of the temperature drop occurring during industrial processes. The multi-stage deformation ability of PM Ti-6Al-4V alloy without decohesion was confirmed. It has also been shown that the application of increasing total strain at a controlled temperature changes the samples resulting in the refinement of the microstructure and leads to the fragmentation of lamellae. The results obtained from MaxStrain tests were verified by multi-stage hot-rolling tests. Defect-free products were obtained, whose good quality was confirmed by the microstructural observations as well as by the investigations of their properties. The results of the rolling tests confirmed the possibility of hot processing of Ti-6Al-4V alloy compacts in industrial conditions, applying large total strain.