纯钒的高温力学性能及断口特征

采用热等静压法制备了纯钒样品，测试了纯钒在700~1100 ℃下的高温力学性能，分析了高温拉伸样品的断口形貌、金相组织。结果表明，随温度的升高，纯钒的强度及韧性均呈下降趋势。700~800 ℃，纯钒具有较好的高温强度及韧性，断口为韧性特征；900~1100 ℃，纯钒的力学性能急剧恶化，断口上出现了大量的解理面及一定的由高温蠕变导致的韧性沿晶，呈现出韧脆断共存的微观形貌；温度升高，解理面有长大趋势。

High Temperature Mechanical Properties and Fracture Characteristics of Pure Vanadium

Pure vanadium samples were prepared by hot isostatic pressing (HIP) technology. High temperature mechanical properties of the as-prepared samples in the range of 700-1100 oC were tested by means of high temperature tensile testing. The fracture surfaces and microstructures were analyzed using scanning electron microscope (SEM) and optical microscope (OM). The results show that the tensile strength, elongation and reduction in area are temperature-dependent and show approximately linear decrease with increasing the temperature. Vanadium possesses good tensile strength and ductility as the tensile temperature is 700-800 oC, and shows a feature of ductile fracture. However, a mixed ductile-brittle fracture surface is observed at the testing temperature 900-1100 oC and the cleavage face is increased with the tensile temperature rising.