The effects of post cold spray heat treatments on microstructure & Mechanical properties of 7075 Al depositions

Cold spray has been employed for depositing 7075 aluminum alloy unto 7075 substrate. The main focus of this study is to investigate the effect of post cold spray processing heat treatment on the microstructure and mechanical properties of the deposited material. For this purpose, several specimens were excised from the deposition and heat treated to different conditions and then were tested via microtensile testing. The obtained mechanical properties were correlated with the microstructural characterization obtained via different microscopy techniques. The results show that some microstructural healing at the particle-particle interfaces occurs even with low temperature heat treatments resulting in superior mechanical properties in the deposited material. Reduction in porosity, substantial improvement in interparticle bonding along with very limited grain boundary migration in the course of annealing were found to be the most important reasons for the ductile characteristics of these samples.