Effects of thermal treatment on mechanical properties of Mg-Y-Nd Mg alloy

• 1、School of Materials and Energy, Southwest University, Chongqing 400715
• 2、 Guizhou Institute of Metallurgical & Chemical Engineering, Guiyang 550002

Abstract：This article used hot extrusion and hot rolling to prepare rolled Mg-Y-Nd Mg alloy plate. The effects of different temperatures on the microstructure, mechanical properties and fracture behavior of rolled Mg-Y-Nd plate were studied. The results showed that the rolled Mg-Y-Nd alloy had a tilt basal texture. The average grain size was about 30μm, and the matrix contained a small amount of twins and a large number of dislocations. Annealing below 450℃will precipitate a large amount of precipitates, but will not cause static recrystallization. Annealing at 300℃ will precipitate a fineβphase, leading to an increase in yield strength. Annealing at 450℃ will produce a large number of coarse spherical particles, resulting in a decrease in yield strength and an increase in plasticity. Annealing at solution temperature caused complete recrystallization, and the grain size was coarsened to above 70μm. The β phase produced by annealing at 300℃ caused the fracture mechanism to change from microporous aggregate fracture to cleavage fracture. The coarse spherical precipitates precipitated at 450℃ will not cause the fracture mechanism to change. After annealing at 525℃,large cleavage planes appeared on the fracture surface due to the coarsening of the grains.

Keywords： Mg alloy Rolling Mechanical properties Fracture behavior Annealing