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研究了不同热压温度和时间对Cr-33at%Nb合金显微组织及氧化行为的影响,并用SEM和X射线衍射对合金组织及氧化产物进行了分析。结果表明,热压温度升高有利于组织致密,保压时间延长有利于Laves相NbCr2热反应合成。不同热压条件制备的Cr-Nb合金在1200℃的氧化动力学均近似符合抛物线规律,氧化膜均由两部分组成,外层为Cr2O3,内层为CrNbO4。随着热压温度的升高,合金氧化速率减小;保压时间由15min延长到80min时,合金氧化速率逐渐减小,但当达到120min时,氧化速率又有所提高。
The effects of different hot pressing temperature and time on the microstructure and oxidation behavior of Cr-33at% Nb alloy were studied. The microstructure and oxidation products of the alloy were analyzed by SEM and X-ray diffraction. The results show that the hot pressing temperature is conducive to the organization of dense, dwell time is conducive to Laves phase NbCr2 thermal reaction synthesis. The oxidation kinetics of Cr-Nb alloy prepared at different hot-pressing conditions almost accord with the parabolic law at 1200 ℃. The oxide film consists of two parts, the outer layer is Cr2O3 and the inner layer is CrNbO4. With the increase of hot pressing temperature, the oxidation rate of the alloy decreases. When the dwell time is extended from 15min to 80min, the oxidation rate of the alloy decreases gradually. However, the oxidation rate increases after 120min.