Experimental investigation and modelling of mechanical strength and damage evolution of fully martensitic wrought and Additive Manufactured Ti6Al4V-grade 5

In this work the experimental investigation and constitutive modelling of wrought and additively manufactured Ti6Al4V (TI64), both having a similar microstructure predominantly consisting of acicular martensitic (α′) phase, are presented.

Commercial TI64-grade 5 was supplied in form of bars and was rapid heated into a single β phase region and, successively, quenched in water to obtain a fully martensite microstructure. Ti64 AM was produced by means of the SLS and SLM processes. Smooth and round notched bar specimens were machined and tested in quasi-static and dynamic regimes. The quasi-static tests were carried out both in tension, on smooth specimens at different temperature and on round notched samples at room temperature, and compression. Dynamic tensile tests were performed by means of Direct Tensile Hopkinson Bar. Based on experimental results, an appropriate constitutive model, combining a yield function surface, a hardening law, and a damage model, was developed.