Scanning strategy optimization for the selective laser melting additive manufacturing of Ti6Al4V

Abstract

Minimizing the residual stress and deformation of the manufactured product consequent to the selective laser melting (SLM) process is always a primary focus in the realm of additive manufacturing. This paper studied the influence of different scanning strategies on the thermal-mecha nical characteristics of SLM of Ti6Al4V. Numerical simulation and experimental tests were employed concerning three scanning strategies of the SLM process: Z-shaped, outer spiral, and inner spiral. Allowing for the latent heat of phase change, thermal radiation, and convection effect, the temperature history, and distribution of the specimen were analyzed, based on which the indirect thermal-mechanical coupling method was engaged for the residual stress and deformation analysis. The result shows good consistency in deformation characteristics between the numerical prediction and experimental observation. A reasonable scanning strategy is beneficial to mitigating the non-uniform distribution of the residual stress, and compared with the outer spiral and inner spiral strategies, the z-shaped scanning strategy may have a better effect in forming accuracy and mechanical properties.