Ti2AlNb电热拉伸行为及组织演变

    Electrothermal Stretching Behavior and Structure Evolution of Ti2AlNb

    • 摘要: 在脉冲电流为50、53、57、60 A时,分别得到700、800、900、1000℃的平衡初始温度,配合不同的应变速率对Ti2AlNb进行了电热拉伸试验,对比分析了Ti2AlNb在原始状态与不同电流状态下材料的力学性能及组织特征。结果表明,随电流的增大、应变速率的减小,Ti2AlNb力学性能逐渐减小。初始电流为50、53、57 A时试样的断裂形式为塑性断裂,呈现微孔聚集型;其他加载电流(初始温度)和应变速率下破坏方式为熔断。加载电流(初始温度)提高,O相和α2相急剧减少,α2相的减少致使其对B2/β相的钉扎作用不断减弱,B2/β相不断长大。应变速率降低同样伴随着O相和α2相的含量减少和B2/β相长大,本质在于温度影响。

       

      Abstract: With the pulse current of 50 A, 53 A, 57 A and 60 A, the equilibrium initial temperature of 700 ℃, 800 ℃,900 ℃ and 1000 ℃ was obtained respectively. With different strain rates, the electrothermal stretching test of Ti2AlNb was carried out. By comparing, the mechanical properties and microstructure of Ti2AlNb under the original state and different current states were analyzed. The results show that the mechanical properties of Ti2AlNb gradually decrease with the increase of current and the decrease of strain rate. When the initial current is 50 A, 53 A and 57 A, the fracture mode of the sample is plastic fracture, showing microporous aggregation type. The failure mode under other loading current(initial temperature) and strain rate is fusing. As the loading current(initial temperature) increases, the O phase and α2 phase decrease sharply. The α2 phase decrease makes the binding effect on B2/β phase weaken, and the B2/β phase continuously grows. The decrease of strain rate is also associated with the decrease of O phase and α2 phase content and the increase of B2/β phase, which is essentially due to the effect of temperature.

       

    /

    返回文章
    返回