Influence of the physicochemical properties of reusable powders on the mechanical properties of Ti6Al4V manufactured via laser powder bed fusion additive manufacturing.

Laser powder bed fusion additive manufacturing (L-PBF AM) technology holds notable advantages regarding raw material reusability. Nonetheless, a notable gap exists in extensive research assessing how the reuse of powders influences their intrinsic physicochemical traits as well as the mechanical attributes of the fabricated components. This study focuses on introducing an innovative approach to Ti6Al4V powder recycling in L-PBF AM, involving the incorporation of virgin spherical powder to maintain powder characteristics prior to printing. This results in sustained mechanical properties throughout seven cycles of printing (P7), with the fifth print (P5) showcasing the optimal mechanical performance (strength of 1185 MPa and elongation of 6.3%). Transmission electron microscopy (TEM) analysis was performed before and after the P5 tensile experiments，revealing a high amount of primary twinning {10 1 ¯ 1 } in LPBF. This study offers both theoretical insights and practical validation, thereby lending substantial support to the advancement of metal AM industrialization. [Display omitted] • Addition of new powder effectively controls the performance of reused powder. • Reused powder's low oxygen content contributes to excellent mechanical performance. • The presence of massive primary twins {10 1 ¯ 1 } in LPBF samples due to rapid cooling. • Numerous primary twins {10 1 ¯ 1 } enhance the plasticity of the LPBF samples. [ABSTRACT FROM AUTHOR]