Precipitation Behavior and Strengthening and Toughening Mechanisms of Pre-fabricated Strong Basal Texture AZ80 + 0.4%Ce Alloy Under Room-Temperature Pre-deformation Coupled with Dual-Stage Aging Conditions

Abstract

This work presents the modified precipitation behavior of the β phase in a Mg-8.0Al-0.5Zn-0.2Mn-0.4Ce alloy (wt%, designated as AZ80 + 0.4%Ce), which has been subjected to room-temperature pre-compression and a subsequent dual-stage aging treatment, thereby imparting it with the pronounced basal texture. It was found that the synergistic application of pre-compression and dual-stage aging protocol markedly accelerates the age-hardening response and architecture of the continuous precipitates (CPs) in the present AZ80 + 0.4%Ce alloy. Consequently, this alloy achieves an exceptional balance between strength and ductility, boasting a yield strength of approximately 229.0 MPa alongside an elongation of around 7.0%. A series of microstructural characterizations reveal that high-density intragranular dislocations introduced by pre-compression serve as catalysts for the preferential formation of CPs over the discontinuous precipitates, effectively suppressing the latter. Notably, this also facilitates static recrystallization, which refines the grain structure and alleviates the residual stresses induced by deformation, further enhancing the mechanical properties. This research contributes a novel perspective to the thermomechanical processing design of precipitation-hardened lightweight alloys, offering a pathway to optimize their performance through tailored thermomechanical strategies.