Kuo Cheng-Hsien, Chen Tao-Hsing, Zeng Ting-Yang
Department of Mold and Die Engineering, National Kaohsiung University of Science and Technology, Kaohsiung 80778, Taiwan.
Department of Mechanical Engineering, National Kaohsiung University of Science and Technology, Kaohsiung 80778, Taiwan.
Materials (Basel). 2021 Sep 3;14(17):5056. doi: 10.3390/ma14175056.
TiAl-based intermetallic alloys are prepared with Cu concentrations of 3-5 at.% (atomic ratio). The mechanical properties and microstructural characteristics of the alloys are investigated under static and dynamic loading conditions using a material testing system (MTS) and split-Hopkinson Pressure Bar (SHPB), respectively. The electrochemical properties of the various alloys are then tested in Ringer's solution. It is shown that the level of Cu addition significantly affects both the flow stress and the ductility of the samples. For Cu contents of 3 and 4 at.%, respectively, the flow stress and strain rate sensitivity increase at higher strain rates. Furthermore, for a constant strain rate, a Cu content of 4 at.% leads to an increased fracture strain. However, for the sample with the highest Cu addition of 5 at.%, the flow stress and fracture strain both decrease. The X-ray diffraction (XRD) patterns and optical microscopy (OM) images reveal that the lower ductility is due to the formation of a greater quantity of γ phase in the binary TiAl alloy system. Among all the specimens, that with a Cu addition of 4 at.% has the best anti-corrosion performance. Overall, the results indicate that the favourable properties of the TiAlCu sample stem mainly from the low γ phase content of the microstructure and the high α phase content.
制备了铜浓度为3 - 5原子百分比（原子比）的钛铝基金属间化合物合金。分别使用材料测试系统（MTS）和分离式霍普金森压杆（SHPB）在静态和动态加载条件下研究了合金的力学性能和微观结构特征。然后在林格氏溶液中测试了各种合金的电化学性能。结果表明，铜的添加量显著影响样品的流动应力和延展性。对于铜含量分别为3原子百分比和4原子百分比的情况，在较高应变速率下流动应力和应变率敏感性增加。此外，对于恒定应变速率，铜含量为4原子百分比会导致断裂应变增加。然而，对于铜添加量最高为5原子百分比的样品，流动应力和断裂应变均降低。X射线衍射（XRD）图谱和光学显微镜（OM）图像显示，较低的延展性是由于在二元TiAl合金体系中形成了大量的γ相。在所有试样中，铜添加量为4原子百分比的试样具有最佳的耐腐蚀性能。总体而言，结果表明TiAlCu样品的良好性能主要源于微观结构中低γ相含量和高α相含量。
