The mechanical behavior of the Ti6Al4V/Ti/Ti6Al4V composite produced by directed energy deposition under impact loading

Abstract

Additive manufacturing (AM) technologies allow to produce the 3D parts of complex geometry using strong materials such as Ti6Al4V alloys. Moreover, the functionally graded materials can be easily created by AM. By combining the material with opposite mechanical characteristics, such as the ductile Ti metal and the strong Ti6Al4V alloy, it is possible to increase the total strength-ductility of the composite material which extends its application area. In the present work, the effect of the Ti layer in the Ti6Al4V/Ti/Ti6Al4V composite on the mechanical behavior of the material is considered. The value of the Ti part plays a key role in the impact strength of the composite material for as-built and annealed states. The heat treatment significantly increases the impact strength by removing the brittle martensite phase. For the tensile properties, the benefits of the combination ductile-strength properties are achieved only after the heat treatment of the composite due to a dominance of the brittleness from the Ti6Al4V part.