Hall–Petch relation and grain boundary slipping in Al Mg Sc alloys with fine equiaxed grain structure

Abstract

Al–Mg–Sc alloys with fine equiaxed grain structure and free of Mg segregation and dislocations were fabricated by friction stir processing and post-solution treatment to study the deformation behavior of Al Mg base alloys at room and elevated temperatures. The k -value in the Hall–Petch equation of the alloys increased with increasing Mg content, and the equation of k -values and Mg content was displayed. Grain refinement and high Mg content not only could reduce the grain boundary (GB) sliding temperature of Al–Mg–Sc alloys during elevated-temperature deformation but also enhance their high-temperature GB sliding capacity. • k -value in H P equation of Al–Mg–Sc alloys increased with increasing Mg content. • k -value of Al–Mg–Sc alloys was developed in the form of k = − 80.56 × exp − c 1.94 + 148.2 . • Grain refinement and high Mg content reduced the GB sliding temperature. • Grain refinement and high Mg content promoted the high-temperature GBs sliding.