Effect of aging treatment on the improvement of tensile properties of Mg۹۵.۵Y۳Zn۱.۵ (at.%) alloy

The microstructural evolution of Mg۹۵.۵Y۳Zn۱.۵ (at.%) alloy during annealing at ۸۲۳ K for ۴.۵hand age hardening treatment was investigated in order to formation of ۱۴H phase. The resultsshowed that the as-cast Mg۹۵.۵Y۳Zn۱.۵ alloy was composed of ۱۸R phase and α-Mg phase. The۱۸R phase was thermally stable and was not transformed into ۱۴H long period stacking ordered(LPSO) phase during annealing. The lamellar ۱۴H LPSO phases were observed with agingtreatment at ۴۷۳ K. The ultimate tensile strength (UTS) and hardness before the aging treatmentwere ۱۶۰ MPa and ~۸۰ HV, respectively. On the other hands, after aging treatment at peakaging time, these properties showed over ۲۱۰ MPa and ۸۶.۱۵ HV, respectively. Controlling themorphology of the LPSO phase and formation of ۱۴H phase in this alloy was found to be aneffective strategy for further improving the mechanical properties.

کلیدواژه ها:

Magnesium alloy ، LPSO phase ، age hardening ، Mechanical properties