Microstructure and mechanical properties of laser rapid formed Ti-6Al-4V alloy

Laser rapid forming is a new and advanced manufacturing technology, which can be used to realize net shape forming of dense metal components with high performance without dies. In this paper powders of the alloy Ti-6Al-4V were used as deposited layer-by-layer to built up solid parts with complex structure. The microstructure and mechanical properties of laser formed Ti-6Al-4V alloy were analyzed. It has been found that although the microstructure of laser formed components is composed of huge columnar prior R grains which grow epitaxial from the substrate and cross several layers, the substructure within prior beta grains is mainly made up of the very fine acicular alpha and basket weave matrix of alpha+beta. Thus the mechanical properties of laser formed Ti-6Al-4V alloy are similar to or even over those of wrought alloy. Further, the mechanical properties display the characteristic of anisotropy.