高强度Ti-Cu-Ni系合金的力学性能

Mechanical Properties of High Strength Ti-Cu-Ni Alloys

采用铜模铸造法制备了直径为2mm的Ti50Cu50-xNix(x=8～40)系列合金,通过扫描电镜、X-射线(XRD)、以及压缩试验对合金的组织、相组成、力学性能及断口形貌进行了研究。结果发现:该合金系均由晶态相组成,没有发现非晶相的存在;压缩试验表明:随着Ni含量的增加,合金的断裂强度和塑性变形量随之增加,屈服强度呈现出先增加后降低的趋势;当Ni含量为40at.%时,断裂强度达到了2200MPa,塑性变形量达到2%,且具有明显的两次屈服现象。

The Ti-Cu-Ni alloys with 2 mm diameters have been fabricated by copper mold casting. Microstructures of the as-cast specimens were investigated by using of scanning electron microscopy （ SEM ）. The phase nature was determined using X-ray diffraction （XRD） analysis. The mechanical properties were measured by uniaxial compressive test at room temperature. The fractured surfaces of samples were investigated by SEM. The result shows that the as-cast alloys are made of crystalline phases, and do not contain amorphous phase. The compressive test shows that the fracture strength and the plasticity increase with increasing Ni content, but yielding strength increases firstly and then decreases with increasing Ni content. The Ti50Cu10Ni40 alloy exhibits excellent mechanical properties： the compressive fracture strength of 2 200 MPa and the plastic elongation of 2% were obtained. Two obvious yielding behaviors during compression for the Ti50Cu10Ni40 alloy were observed.