Effect of mischmetal and yttrium on microstructures and mechanical properties of Mg-Al alloy
(State Key Laboratory of Die and Mould Technology,
Huazhong University of Science and Technology,Wuhan 430074, China)
Huazhong University of Science and Technology,Wuhan 430074, China)
Abstract: The effect of yttrium and mischmetal(MMs) on the as-cast and solid solution treated structures of Mg-Al alloys with different Al-contents was investigated. The results show that the MMs in Mg-Al alloy existed in rod Al4(Ce, La)compound while Y in Mg-Al alloy in polygonal Al2Y compound. The amount of Mg17Al12 in Mg-Al alloy is decreased with increasing Y or MMs addition, and Mg17Al12 intermetallic compound is changed from continuous network to discontinuous one. The Al4(Ce, La) and Al2Y compounds are not dissolved into Mg-Al alloy matrix during solid solution treatment so that their high heat stability can be exhibited. The experiment of mechanical properties indicate that elongation and impact toughness of the Mg-Al-Y alloy with polygonal Al2Y compound are higher than those of Mg-Al-MMs alloy with rod Al4(Ce, La) compound
Key words: alloy; yttrium and mischmetal; Mg-Al structure and property; microprobe