Experimental and Numerical Investigation on Bending Behavior of Ti-6al Parts Produced by Additive Metal Laser Sintering

Abstract

In this study, the bending strength characteristic of test specimens manufactured by the direct metal laser sintering method was investigated for different values of additive manufacturing (AM) parameters. The effect of heat treatment on bending strength was also researched by applying annealing and recrystallization annealing to the Ti-6Al-4V parts after the AM. The difference of bending strength values mainly resulting from the heat treatment processes has been explained by microstructural examinations of the specimens manufactured with default AM parameters set. The completed bending tests were verified by finite element analysis models. Moreover, the comparison of the specimen properties was made by material characterizations and density measurements. As a result of the bending tests, the usage of 180 mu m instead of 140 mu m which is the standard hatch spacing value of the additive machine provided the same level of bending strength with a shorter manufacturing period of time. In addition, higher bending strengths were obtained when the lower-cost annealing heat treatment was applied after the AM. Furthermore, the bending strength values of the specimens verified by the finite element method with a difference of 11.6%.