Abstract:Based on Mo equivalent design, novel Ti-6Al-xMo(x = 2, 3, 4) titanium alloys was deposited by laser solid forming (LSF) from mixed Ti, Al and Mo elemental powders, and the microstructure and room temperature tensile properties of the alloys were investigated. The results showed that the solidification microstructure of the three alloys presents a coarse columnar grains growing along the direction of <100>, and the top is composed of equiaxed grains. With the increase of Mo content, the average width of the columnar grains decreases, and the thickness of the equiaxed grains layer increases gradually. The microstructure in primary β grains is composed of primary α lath and retained β phase, and there also exits grain boundary α and α colonies. With the increase of Mo content, the width and area ratio of primary α lath decrease. When the Mo content increases to 4 wt.%, the secondary α phase appears in the grain. Moreover, 12 α variants were found in all the three components by Electron Backscatter Diffraction (EBSD) analysis, and the variation was dominant. In terms of mechanical properties, the strength and hardness increase with the increase of Mo content while the elongation decreases. By contrast, Ti-6Al-2Mo and Ti-6Al-3Mo have the very good tensile properties of 962 MPa tensile strength and 11.5% elongation, and 982 MPa tensile strength and 9.2% elongation, respectively.