Texture weakening effect from {1011} twins induced static recrystallization in ambient extrusion AZ31 magnesium alloy

In magnesium alloys, {1011} twins have great effect on their recrystallization behavior due to the high strain concentration in twinning zones. In this study, isothermal annealing was conducted on ambient extrusion AZ31 magnesium bars to investigate {1011} twins related static recrystallization and texture weakening effect. The results show that, during annealing, static recrystallization occurs firstly in {1011} twinning zones. After 300celcius annealing, equiaxed grains are obtained in these extrusion bars. With the increasing extrusion strain, the grain size decreases gradually and the basal texture becomes weaker. Tensile and compressive yield strength show a significant decrease after annealing, meanwhile, they follow a Hall-Petch relationship. However, a negative Hall-Petch coefficient K is found in tensile tests where the tensile yield strength decreases gradually with the reduced grain size. Different contribution from grain refinement and texture weakening on yield strength are discussed and separated. The texture weakening effect from {1011} twins induced static recrystallization is responsible for the negative Hall-Petch coefficient K during tensile tests.& COPY; 2023 Published by Elsevier B.V.

Automated summary

Isothermal annealing was conducted on AZ31 magnesium bars to investigate {1011} twins related static recrystallization and texture weakening effect. The results show that static recrystallization occurs firstly in {1011} twinning zones during annealing, leading to equiaxed grains in the bars. With increasing extrusion strain, grain size decreases gradually and the basal texture becomes weaker. Tensile and compressive yield strength show a significant decrease after annealing, following a Hall-Petch relationship, with a negative Hall-Petch coefficient K observed in tensile tests.