(北京有色金屬研究總院，北京 100088)
摘 要: 利用XRD、OM、SEM、TEM測試技術(shù)和室溫拉伸試驗研究均勻化熱處理對Mg-7Gd-3Y-1Nd-1Zn- 0.5Zr(質(zhì)量分?jǐn)?shù)，%)合金顯微組織及力學(xué)性能的影響。結(jié)果發(fā)現(xiàn)，鑄態(tài)組織主要由α-Mg、(Mg, Zn)3RE相和堆垛層錯組成，熱處理使(Mg, Zn)3RE部分回溶、晶界附近的堆垛層錯消失，但沿著晶界產(chǎn)生了塊狀14H型長周期堆垛有序(LPSO)相。鑄態(tài)合金的抗拉強度、屈服強度和伸長率分別為187 MPa、143 MPa和3.1%；而經(jīng)均勻化熱處理后合金的抗拉強度、屈服強度和伸長率分別為229 MPa、132 MPa和7.2%。
關(guān)鍵字: 鎂合金；長周期堆垛有序相；堆垛層錯；顯微組織演變；力學(xué)性能
（Beijing General Research Institute for Non-ferrous Metals, Beijing 100088, China）
Abstract:X-ray diffraction (XRD), optical microscopy (OM), scanning electronic microscopy (SEM), transmission electron microscopy (TEM) and tensile tests at room temperature (RT) were performed to investigate the effect of homogenization on microstructure evolution and mechanical properties of Mg-7Gd-3Y-1Nd-1Zn-0.5Zr (mass fraction, %) alloy. The results indicate that the microstructure of the as-cast alloy is composed of α-Mg, (Mg, Zn)3RE phase and stacking fault (SF), the homogenization results in the disappearance of (Mg, Zn)3RE phase and stacking fault (SF) as well as the emergence of 14H-type long-period stacking ordered (LPSO) phase. The ultimate tensile strength (UTS), yield strength (YS) and elongation of the as-cast alloy are 187 MPa, 143 MPa and 3.1%, and the UTS, YS and elongation of the as-homogenized alloy are 229 MPa, 132 MPa and 7.2%, respectively.
Key words: magnesium alloy; long-period stacking ordered (LPSO) phase; stacking fault; microstructure evolution; mechanical properties
