SPS制备TiNi增强镁合金复合材料的微观结构及力学性能

摘要

The Mg alloy matrix composite reinforced by shape memory alloy TiNi wires was fabricated by Spark Plasma Sintering (SPS) process of AZ31 Mg alloy plate with TiNi SMA wires.The microstructure of TiNi reinforced Mg alloy composites was analyzed by microscopic analysis methods,including OM,SEM and EDS.The transformation of TiNi wires was analyzed by DSC and XRD.The mechanical properties of the composite materials at room temperature and high temperature were studied by quasi-static tensile test as well.The results show that a 2 μm mutual diffusion layer of Ti,Ni and Mg forms at the interface of the TiNi/Mg composite.The tensile properties of the composite at high temperature are better than RT.The yield strength,tensile strength and elastic modulus of the composite are higher than that at room temperature (157 MPa,292 MPa,22 GPa,respectively),i.e.increase by 12％,33％ and 29％,respectively,at 100℃,and higher than that at room temperature(143 MPa,251 MPa,20 GPa,respectively),i.e.increase by 2％,14％ and 18％,respectively,at 150℃.%以AZ31镁合金为基体,TiNi形状记忆合金丝为增强体,利用放电等离子烧结法(SPS)制备了TiNi/Mg复合材料,用OM、SEM、EDS对其微观形貌进行表征,并用XRD及DSC研究TiNi丝的相变,同时对该复合材料进行准静态拉伸实验,对其室温及高温力学性能进行研究.结果表明,所制备的TiNi/Mg复合材料中界面处存在Mg、Ti、Ni元素的互扩散现象,并形成宽度约为2μm的互扩散层;所制备的TiNi/Mg复合材料的高温力学性能高于室温,其中其屈服强度、抗拉强度及弹性模量在100℃时(分别为157MPa,292 MPa,22 GPa)较室温分别提高了12％、33％和29％,150℃时(分别为143 MPa,251 MPa,20 GPa)较室温分别提高了2％、14％和18％.