Texture, Second-Phase Particles, and the Anisotropy of Deformation Behavior in TTMP AZ61

Abstract

The deformation, damage accumulation, and fracture behavior of thixomolded and thermomechanically processed AZ61 were studied by room temperature uniaxial straining. The material was examined in as-molded, as-rolled, and rolled + annealed conditions. The yield strength and work hardening behavior are controlled primarily by grain size and crystallographic texture, which reaches a maximum of only 4.8 multiples of random density in the as-rolled material. The low degree of texture results in a low degree of plastic anisotropy (Lankford r value), suggesting good formability properties. In addition, it is shown that although the β-phase particles begin to crack as early as 4 pct elongation, their presence does not lead to a decrease in ductility, as β-phase cracks do not coalesce to initiate fracture.