基于激光选区熔化(SLM)工艺制备了一种具有高致密度、高强度和高硬度的Cu-13.5Al-4Ni-0.5Ti形状记忆合金试样。对试样的微观组织进行分析表征,并研究了其在室温和300 ℃下的拉伸性能。结果表明:当激光能量密度约为110 J·mm ^-3时,试样的相对密度最大,超过99.5%;试样微观组织中平行延伸的板条状马氏体横跨熔化道生长,晶粒平均尺寸约为43 μm,与铸造试样相比,晶粒得到明显细化;试样在常温下的抗拉强度为(541±26) MPa,断后伸长率为(7.63±0.39)%;在300 ℃下的抗拉强度提高至(611±9) MPa,断后伸长率提高至(10.78±1.87)%,该合金在高温领域具有一定的应用潜力。

Copper-based shape memory alloys Cu-13.5Al-4Ni-0.5Ti with high relative density, high strength and high hardness are fabricated by selective laser melting (SLM). The microstructures are characterized and the tensile properties at room temperature and 300 ℃ are evaluated, respectively. The results show that the maximum relative density of 99.5% is obtained when the laser input energy is 110 J·mm -3. The lath martensite extending in parallel in the microstructure of the sample grows across the melting tracks and the average grain size is about 43 μm, The grain size of the SLM-fabricated sample is smaller than that of the casting sample. The average tensile strength and percentage elongation after fracture of the SLM-fabricated sample are (541±26) MPa and (7.63±0.39)% at room temperature, respectively, and the tensile strength is increased to (611±9) MPa at 300 ℃, and the percentage elongation after fracture is increased to (10.78±1.87)%. The SLM-fabricated alloy shows a good application potential in the high temperature fields.