Hot Workability and Processing Maps of 7150 Aluminum Alloys with Zr and V Additions

Abstract

The hot workability and processing maps of 7150 aluminum alloys with different Zr additions (0-0.15 wt.%) and V additions (0.01-0.15 wt.%) were investigated using uniaxial compression tests conducted at various temperatures (300-450 °C) and strain rates (0.001-10 s−1). The results reveal that the processing map of the 7150 base alloy exhibits a single domain (Domain I) associated with dynamic recovery and partially dynamic recrystallization. With the increasing Zr and V additions, Domain I shrinks toward higher temperatures and higher strain rates and exhibits decreases in efficiency of power dissipation due to a restrained level of dynamic recovery caused by the pinning effect of Al3Zr and Al21V2 dispersoids. When the added Zr and V contents reach 0.15%, another domain (Domain II) is formed, corresponding to cavity formation in the microstructure. Flow instability during hot deformation of 7150 alloys is attributed to the formation of adiabatic shear bands and deformation bands. The instability region extends toward lower strain rates when alloyed with Zr and V. The optimum hot-working parameters for those alloys are determined to be a deformation temperature of 450 °C and a strain rate of 0.01 s−1.