Influence of Strong Static Magnetic Field on Solution and Aging Behavior in AZ91 Magnesium Alloys

摘要

A strong static magnetic field (SSMF) of about 10T was introduced to the solution treatment and aging process of AZ91 magnesium alloy. Compared with the conventional non-SSMF-solution and aging, the dissolving rates of Mg_(17)Al_(12) in the SSMF solutionized specimens was first retarded; however, after 10 hours no clear difference can be found in the optical microstructures. Furthermore, in the first stage of SSMF aging, discontinuous precipitates of Mg_(17)Al_(12) at grain boundaries were promoted, and SSMF pre-aging leads to a higher density of continuous precipitates. The highest hardness of the SSMF pre-aged specimens is significantly_higher than that one of the non-SSMF aged specimens. The relatively lower diffusion rate of Al atoms in the matrix and the free energy change of different phases induced by the SSMF could affect the microstructure evolution in the solution treatment and aging process.