(1. 上海交通大学 材料科学与工程学院，上海 200240；
2. 怀卡托大学 工程系 先进材料中心，新西兰 汉密尔顿 3105)
摘 要: 利用快速粉末压坯锻造和粉末压坯挤压的方法制备高致密度纯钛样品。在室温条件下，对两种纯钛试样以应变速率1×10-4 s-1进行拉伸实验。采用光学显微镜和扫描电镜观察两种材料的显微组织，以及拉伸试样断口和断口附近纵切面的形貌，研究两种试样的断裂机制和固结情况。结果表明，锻造纯钛和挤压纯钛都具有α相片状组织和较高的氧含量，均具有较高的抗拉强度。从断口形貌分析可知，两种试样的拉伸断裂均属于韧性断裂，在应变速率1×10-4 s-1下试样断口附近纵切面上未发现明显的由粉末颗粒被拉开所造成的空洞，说明粉末坯在非常短的时间内就达到了非常好的固结状态。
关键字: 纯钛；粉末冶金；拉伸性能；锻造；挤压；显微组织
（1. School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China;
2. Waikato Center for Advanced Materials, School of Engineering, University of Waikato,
Private Bag 3105, Hamilton, New Zealand）
Abstract:High density titanium samples were prepared by rapid powder compact forging and powder compact extruding respectively, and their tensile properties were investigated under strain rate of 1×10-4 s-1 at room temperature. The microstructure, fracture surface and morphology of the longitudinal section near fracture surface of the tensile test samples were observed by optical microscope and scanning electron microscope. The results show that both powder compact forged titanium and powder compact extruded titanium have very high tensile strength due to α lamella structure and high oxygen content. The fracture surface analysis of the forged titanium and extruded titanium specimens shows that their fracture modes belong to ductile fracture. No obvious cavities caused by separation of powder particles were observed under strain rate of 1×10-4 s-1, indicating that the samples prepared by powder compact forging or powder compact extrusion have a very good consolidation state in a very short consolidation time.
Key words: pure titanium; powder metallurgy; tensile properties; forging; extruding; microstructure
