摘要
用真空熔炼、真空热处理方法研究了超轻Mg-7.28Li-8.02Y合金的显微组织和力学性能,以及热处理工艺对该合金显微组织和力学性能的影响规律。结果表明,铸态Mg-7.28Li-8.02Y合金主要由β(Li)相基体和α(Mg)相以及沿晶分布呈网状结构的γ(Mg24Y5)相组成。对铸态Mg-7.28Li-8.02Y做固溶热处理后发现,随着淬火温度由300℃升高至500℃,Mg及γ(Mg24Y5)相在β相中的固溶程度增加,合金淬火硬度增加,γ(Mg24Y5)相呈圆球状均匀分布,其共同作用使合金抗拉强度大幅度提高;但150℃时效后,一方面有晶粒长大,另一方面长时间时效使Mg在β相中固溶度降低,α相沿β相晶界析出,导致合金硬度、强度及塑性有所下降。
The microstructure and mechanical properties of the super light Mg-7.28Li-8.02Y alloy were researched by vacuum melting and vacuum heating treatment, and the influence regularity of heat treatment for the alloy was also studied. The results show that the casting Mg-7.28Li-8.02Y alloy contains β （Li） phase in matrix, α（Mg） phase and γ（Mg24Y5） phase mainly distribute along the grain boundary of 13 phase as network structure. The quenching temperature from 300 ℃ to 500 ℃ enables the solid solubility and the quenching hardness of Mg and γ（Mg24Y5） phase in 13 phase to be increased. Meanwhile, when the quenching temperature increases to 500 ℃, the tensile strength has a substantial increase because of much more solid solubility and uniform distribution of globular -/（ Mg24Y5 ） phase. But after aging at 150 ℃, both the grain growing and the decreasing solid solution of Mg in β phase and the α phase precipitation on the β phase boundrary result in the drop of hardness, tensile strength and elongation percentage.
出处
《金属热处理》
CAS
CSCD
北大核心
2008年第8期37-40,共4页
Heat Treatment of Metals
基金
四川省科技厅重点科技攻关项目(0021783)
关键词
镁锂合金
固溶处理
显微组织
抗拉强度
Mg-Li alloy
solution treatment
microstructure
tensile strength
