时效处理对Mg-Y-Gd-Zn-Zr合金中LPSO相演变及性能的影响
Evolution of LPSO phase and properties of Mg-Y-Gd-Zn-Zr alloy at different aging temperatures
任广笑 1王超 2曹喜娟 1王凯 3王红霞 4程伟丽 3牛晓峰3
作者信息
- 1. 山西江淮重工有限责任公司 山西省轻金属及其复合材料研发及结构化应用中试基地,山西晋城 048000
- 2. 太原理工大学材料科学与工程学院先进镁基材料山西省重点实验室,山西太原 030024;航空工业陕西宏远航空锻造有限公司,陕西西安 710000
- 3. 太原理工大学材料科学与工程学院先进镁基材料山西省重点实验室,山西太原 030024
- 4. 山西江淮重工有限责任公司 山西省轻金属及其复合材料研发及结构化应用中试基地,山西晋城 048000;太原理工大学材料科学与工程学院先进镁基材料山西省重点实验室,山西太原 030024
- 折叠
摘要
利用OM、SEM、XRD、TEM及性能测试等方法研究了铸态、固溶时效态Mg-6Y-3Gd-3Zn-0.5Zr合金微观组织演变及其对力学性能的影响.结果表明,铸态合金由树枝状α-Mg基体、晶界处连续网状18R-LPSO和Mg24(Gd,Y,Zn)5混合相组成.固溶处理后大部分Mg24(Gd,Y,Zn)5相与少部分18R-LPSO相回溶到基体内.250℃和300℃时效处理后,合金基体内析出了大量层片状14H-LPSO、Mg3(Y,Gd)及Mg5(Y,Gd)相.400 ℃时效处理后,晶内只析出了 14H-LPSO相.铸态合金的抗拉强度和伸长率分别为222.7 MPa和4.1％.时效处理后合金强度均有所下降,伸长率略微上升.400 ℃峰时效合金由于晶内析出的14H-LPSO数量多、尺寸大,抗拉强度下降最多,相比铸态下降了 39 MPa.
Abstract
The microstructural evolution of the Mg-6Y-3Gd-3Zn-0.5Zr alloys in the as-cast,solid solution and aging states and its influence on the mechanical properties were investigated by using OM,SEM,XRD,TEM and property testing methods.The results show that the as-cast alloy consists of dendritic α-Mg matrix with a continuous network of 18R-LPSO and Mg24(Gd,Y,Zn)5 mixed phases at the grain boundaries.After solid solution treatment,the most of Mg24(Gd,Y,Zn)5 phase and part of the 18R-LPSO phase are dissolved back into the matrix.A large amount of lamellar 14H-LPSO and Mg3(Y,Gd)and Mg5(Y,Gd)phases are precipitated in the matrix after aging at 250 ℃and 300 ℃.Only 14H-LPSO phase is precipitated in the crystals after aging at 400 ℃.The tensile strength and elongation of the as-cast alloy are 222.7 MPa and 4.1％,respectively.The strength of the alloy decreases and the elongation increases slightly after aging.The alloy peak aged at 400 ℃ shows the greatest decrease in strength due to the large number and size of 14H-LPSO precipitated in the crystals,and the tensile strength decreases by 39 MPa compared with that of the as-cast state.
关键词
Mg-Y-Gd-Zn-Zr合金/LPSO相/热处理/力学性能Key words
Mg-Y-Gd-Zn-Zr alloy/LPSO phase/heat treatment/mechanical properties引用本文复制引用
基金项目
山西省科技成果转化引导专项(202204021301009)
山西省科技成果转化引导专项(202104021301022)
山西省自然科学基金(20210302123135)
中央引导地方科技发展资金(YDZJSX20231B003)
出版年
2024
NETL
NSTL
万方数据