NbCr2/ Nb合金高温力学行为

High temperature mechanical behavior of NbCr2/ Nb alloy

摘要:

在800-1200℃的变形温度,0.001-0.1s_-1的应变速率下对通过机械合金化+热压工艺制备的成分为Nb-22.5Cr的 NbCr₂/ Nb合金进行了高温压缩试验,研究了合金的高温力学行为,并通过透射电子显微镜观察分析了合金的变形机制。结果表明：NbCr₂/ Nb合金的峰值强度随着变形温度的升高,应变速率的降低而下降。基体Nb的变形机制主要为位错的滑移；而NbCr₂的变形机制为通过层错,孪晶,不全位错等方式进行。

Abstract:

Compression tests between 800 and 1200℃ and 10_-3 and 10_-1s_-1 and conventional transmission electron microscopy have been employed to investigate the high temperature mechanical behavior and the deformation mechanisms of the NbCr₂/Nb alloy with the composition Nb-22.5 at.% Cr, prepared by mechanical alloying and hot pressing process. The results show that the peak strength of NbCr₂/Nb alloy decreases with the increase of deformation temperature and the decrease of strain rate. The main deformation mechanism of Nb matrix is the slip of dislocation. While, the deformation mechanism of the Laves phase NbCr₂ is through by stack fault/ twins and partial dislocation.