Filomeno Martina will be presenting on "Additive manufacturing of titanium and aluminium: control of microstructure, mechanical properties and residual stress" (F. Martina, J. Gu, J. Ding, M.J. Roy, P.A. Colegrove, S.W. Williams) in occasion of the specialists’ meeting on Design, Manufacturing and Application of Metallic Lightweight Material Components For Military Vehicles, which will be held in Tallin, Estonia, between the 25-27 April 2016.
The abstract is the following:
Ti-6Al-4V and aluminium alloys are receiving considerable interest in the defence industry due to their excellent strength-to-weight properties. However, some of the manufacturing techniques currently employed are affected by issues including enormous material waste, long lead times, high non-recurring cost associated to tooling. Consequently, additive manufacture is being increasingly investigated as a solution to those problems. In particular, the Wire + Arc Additive Manufacturing (WAAM) process is suitable for large- scale components that can be produced within reasonable times at greatly reduced cost. This manufacturing technique was applied to Ti-6Al-4V and Aluminium 2024, 2319, 4043 and 5087; microstructure, mechanical properties and residual stress were characterised also for specimens with the addition of in-process high- pressure rolling and heat treatments (the latter only for aluminium). For both materials the properties of the WAAM material were better than the wrought alloy, with ultimate tensile strength peaking at 1075 MPa with elongation of maximum 18%, for Ti-6Al-4V; and strength peaking at 500 MPa, with elongation of maximum 22%, for aluminium. Residual stress measured in titanium was also reduced as a consequence of rolling. Finally the applicability of the WAAM process was proven for two lightweight military components, one in Ti-6Al-4V and one in Aluminium 2319.