纯钒制备及其性能

采用热等静压(HIP)技术制备纯钒,利用材料试验机、OM、SEM、TEM和TGA等测试纯钒的力学性能并观察其拉伸断口形貌、进行热重分析.结果表明:热等静压温度在1250 ℃以上可以实现全致密化;随温度的升高,抗拉强度、屈服强度均先降低后增加,延伸率及断面收缩率呈相反趋势变化,在1250 ℃综合性能最佳,抗拉强度、屈服强度分别为701,634 MPa,延伸率为22.4%;断口形貌表现出滑断、微孔聚集等不同的断裂方式,不同温度制备的纯钒试样晶粒大小没有显著变化,均观察到板条马氏体组织存在; 氧化行为符合抛物线规律,活化能为118 kJ/mol.

Study on Preparation and Properties of Pure Vanadium

The pure vanadium was prepared by hot isostatic pressing (HIPing). The mechanical properties of the pure vanadium were examined and the tensile fracture, microstructure and thermal change of the specimen were analyzed by a material testing machine, OM, SEM, TEM and TGA. The results show that pure vanadium can be up to full densification at the HIPing temperature above 1250 oC. With increasing of the temperature, the tensile strength and yield strength decreases at first and then increases, but the plasticity change is on the contrary. Its comprehensive mechanical properties are best at 1250 oC, e.g. the tensile and yield strength are 701 MPa and 634 MPa, respectively, and the elongation is up to 22.4%. Fracture of the specimens happens in the modes of slipping off or micro-porous aggregation. The grain sizes of pure vanadium prepared at different temperatures are similar, and lath-like martensite is observed in all of the specimens. The oxidation processes follow parabolic kinetics, whose activation energy is 118 kJ/mol.