离心铸造和热轧对Mg-10Gd-3Y-1Sn合金组织和机械性能的影响

Effects of Centrifugal Casting and Hot Rolling on Micro-structure and Mechanical Properties of Mg-10Gd-3Y-1Sn Alloy

摘要:

采用离心铸造及热轧工艺制备Mg-10Gd-3Y-1Sn合金，利用X射线衍射、光学显微镜、扫描电子显微镜和拉伸试验对该合金的组织和力学性能进行了研究。结果表明：离心铸造Mg-10Gd-3Y-1Sn合金由α-Mg、Mg₂₄(Gd, Y)₅、Mg₂(Sn, Y)₃Gd₂和Mg₃(Gd, Y)相组成。随着离心半径和离心转速的增大，Mg-10Gd-3Y-1Sn合金的晶粒尺寸逐渐减小，抗拉伸强度逐渐增大。在700 r/min下制备的热轧试样在室温下极限抗拉伸强度为304 MPa，在300 ℃下极限抗拉伸强度为296 MPa。Mg₂₄(Gd, Y)₅、Mg₂(Sn, Y)₃Gd₂和Mg₃(Gd, Y)相具有优异的热稳定性，因而Mg-10Gd-3Y-1Sn合金具有优异的高温抗拉伸强度。

Abstract:

The Mg-10Gd-3Y-1Sn alloys were prepared by centrifugal casting and hot rolling, and their microstructure and mechanical properties were investigated by X-ray diffraction, optical microscope, scanning electron microscope, and tensile tests. Results show that the centrifugal-cast Mg-10Gd-3Y-1Sn alloy consists of α-Mg, Mg₂₄(Gd,Y)₅, Mg₂(Sn,Y)₃Gd₂, and Mg₃(Gd,Y) phases. With increasing the centrifugal radius and rotation speed, the tensile strength of alloys is increased gradually due to the decreased grain size of alloys. The ultimate tensile strength of as-rolled alloys after centrifugal casting with the rotation speed of 700 r/min is 304 and 296 MPa at room temperature and 300 °C, respectively. The improved tensile strength of Mg-10Gd-3Y-1Sn alloy at elevated temperatures mainly results from the Mg₂₄(Gd, Y)₅, Mg₂(Sn, Y)₃Gd₂, and Mg₃(Gd, Y) phases with excellent thermal stability.