中文摘要：

目的了解Nb-16Si-2Fe合金热变形的高温力学行为，并掌握其变形过程中的组织演变。方法采用真空非自耗电弧炉制备了Nb-16Si-2Fe合金，利用Gleeble-1500热模拟机对合金进行高温压缩实验，并通过XRD对合金相结构进行分析。结果合金由白色树枝晶状NbSS固溶体相、灰色连续基体Nb3Si相及黑色块状Nb4FeSi相组成。试样在较低温度、较大变形速率压缩时，产生脆性断裂。在1200～1400℃范围内，随着变形温度的升高及变形速率的降低，试样开裂倾向减小，应力峰值降低。脆性Nb3Si相由连续分布变成孤岛状分布，并发生共析反应分解生成细小两相组织。结论高温压缩过程使硬脆相Nb3Si含量降低，韧性相NbSS相含量增加，合金高温强度下降，一定程度上降低了该合金的塑性加工难度。

英文摘要：

The paper aims to study the high-temperature compressive behavior of Nb-16Si-2Fe alloy and understand its microstructure evolution in the deformation process. The Nb-16Si-2Fe alloy was prepared by vacuum arc melting. Gleeble-1500 was used to compress specimens under high temperature and the metallographic structure was analyzed with XRD. The alloy consists of bright dendritic Nbss, gray continuous matrix Nb3Si and black blocky Nb4FeSi phase. The specimens suffered from brittle fracture when the temperature was relatively low and the deformation rate was large. Within the range of 1200℃ to 1400 ℃, with the increase of temperature and the decrease of deformation rate, the cracking tendency and the peak stress of specimens were reduced. The Nb3Si phase changed from continuous matrix to island shape and the tiny two-phase organization was also generated in the eutectoid reaction. High temperature compression reduces the content of Nb3Si, increases Nbss, and decreases the high temperature strength of alloy, and finally reduces the difficulty of plastic processing to a certain extent.