Dynamic Tensile Deformation of High Strength Aluminum Alloys Processed Following Novel Thermomechanical Treatment Strategies

Abstract

Herein, the effects of a very recently introduced novel thermomechanical process route on the microstructural evolution and dynamic tensile deformation behavior of two different precipitation hardenable aluminum alloys, i.e., AA6082 and AA7075, are studied. The investigated materials are hot formed and quenched in differently tempered tools to reveal the influence of cooling rate. Microstructure analysis is conducted to study the influences of different cooling strategies on the microstructure evolution and prevailing strengthening mechanisms in the investigated conditions. Dynamic tensile tests at strain rates of 40, 200, and 400 s−1 coupled with digital image correlation are further conducted to study the mechanical performance and the local deformation behavior. Experimental results show a decrease in yield and tensile strength for the material quenched at higher tool temperature. With increasing strain rate, strength and elongation to failure of the investigated alloys increase for all conditions. The obtained mechanical properties can be rationalized based on the prevailing microstructural features. Both alloys show fine and well-distributed precipitates upon fast quenching, whereas coarse precipitates prevail upon slow cooling.