A novel laser continuous powder bed fusion of TA15 titanium alloy: Microstructure and properties

This work presents a novel laser continuous powder bed fusion (L-CPBF) process technique, tailored for the additive manufacturing of intricate components with annular hollow structures, emphasizing both precision and efficiency. Utilizing this advanced L-CPBF method, Ti-6.5Al-2Zr-Mo-V (TA15) titanium alloy samples were successfully fabricated, and their microstructures and properties were investigated. The optimized process parameter window for L-CPBF processing of TA15 was determined through Taguchi experiments, ranging from 100 to 125 J/mm3, with the relative density of the samples achieved an outstanding 99.95%. Microstructural evolution under varying volumetric energy densities (VED) was revealed through characterization methods such as SEM and EBSD. The formation of acicular alpha '-martensites was observed during initial the cooling phase, with thermal cycling temperature playing a pivotal role in the development of martensites of varying sizes. Furthermore, through process optimization, remarkable mechanical properties, with a tensile strength of 1200.5 +/- 98.5 MPa, a yield strength of 1109 +/- 102 MPa, and an elongation of 7.05 +/- 1.35% were achieved. These mechanical properties are comparable to those of TA15 alloys prepared by traditional reciprocating scraper powder spreading L-PBF. However, our approach boasts a substantial increase in manufacturing efficiency, surpassing the traditional method by over 45%. Collectively, this study offers invaluable theoretical and experimental insights, paving the way for accelerated additive manufacturing of hollow annular components in demanding sectors such as aerospace and beyond.