A Study on the Microstructure of Direct Laser Fabricated Ti-6Al-4V and Ti-15V-3Cr-3Sn-3Al Alloys

摘要

Direct laser fabrication (DLF) technique can produce near full dense components using laser and powder using CAD files to define the shape of the sample. In this study DLF has been used to produce samples from Ti-6Al-4V and Ti-15V-3Cr-3Sn-3Al powders under a range of laser processing conditions. The effects of process conditions on microstructure and mechanical properties have been investigated. It has found that in the laser deposited samples of (α+β) alloy, Ti-6Al-4V, there is a pronounced tendency to form columnar grains. In contrast the β alloy, Ti-15V-3Cr-3Sn-3Al, tends to form equiaxed grain throughout the samples. The mechanisms for forming columnar or equiaxed microstructures in DLFed materials are discussed in terms of the phase diagram of the materials.