Effect of cryogenic and aging treatments on low-energy impact behaviour of Ti-6Al-4V alloy

The objective of this study is to examine the effects of cryogenic and aging treatments on the impact strength and mechanical properties of Ti-6Al-4V alloy. To accomplish that objective, cryogenic treatment (CT), aging treatment (AT) and cryogenic treatment followed by aging treatment (CAT) were conducted on Ti-6Al-4V alloy. Impact tests were performed on heat-treated and untreated samples using different impactor nose geometries (hemispherical, 60° and 90° conical) to determine the effect of impactor nose geometry on the damage characteristic. The findings showed that energy absorption increased and areas of damage decreased as a result of heat treatment in all treated samples. The highest energy absorption was observed in the CAT samples, due to the increase in energy absorption, the smallest damaged area occurred in the CAT sample, and the largest deformation was seen in the untreated samples. Additionally, it was seen that the damaged area and deflection were strongly dependent on impactor nose geometry. The maximum deflection and narrowest deformation area were seen with 60° conical nose geometry. The deformation area increased with increasing impactor nose angle.