As-built fracture toughness of Ti6Al4V produced by laser powder bed fusion

Abstract

Predicting and preventing stress induced support failure during laser powder bed fusion (LPBF) processing requires knowledge of the fracture toughness of the material in its as-built condition. When performing laboratory measurement of fracture toughness, large residual stresses that are present in the part due to the LPBF process can significantly affect the measurement and must be taken into consideration. In this article, fracture toughness in the as-built condition was measured to be 26 MPa.m1/2 and the residual stress distribution in the crack plane was determined with simulation. Finally, the effective fracture toughness of the material was calculated, using the principle of superposition, to be ~ 47 MPa.m1/2.