TITANIUM ALLOY (Ti-6Al-4V) PROCESSED BY ELECTRON BEAM MELTING: MICROSTRUCTURE AND MECHANICAL BEHAVIOR OF THE AS-BUILT AND HEAT-TREATED MATERIAL

摘要

During electron beam melting of Ti-6Al-4V, the material undergoes a complex process, involving a succession of melting, cooling, and partial re-melting. This thermal history has a considerable impact on the microstructure and mechanical properties. Here, the microstructure and texture of electron-beam melted specimens were characterized by optical microscopy and EBSD techniques. Numerical reconstruction from the room temperature EBSD data evidenced the strong texture of the high temperature β phase. Some specimens underwent additional thermal post-treatments. Depending on the holding temperature and the cooling rate applied, these treatments generated a diverse range of microstructures. The resulting mechanical properties were discussed and compared to those of as-built material.