热处理对真空热压烧结NiCrCoTiV高熵合金组织结构及耐腐蚀性能的影响

Effect of Heat Treatment on Microstructure and Corrosion Resistance of NiCrCoTiV High-entropy Alloy Prepared by Vacuum Hot-pressing Sintering

采用真空热压烧结技术制备了NiCrCoTiV高熵合金,并分别在500℃、600℃和700℃下对高熵合金进行18h保温热处理。采用X射线衍射仪、扫描电子显微镜、电化学测试系统研究了不同热处理温度对高熵合金物相结构、微观组织及耐腐蚀性能的影响。结果表明,高熵合金的物相组成在不同温度热处理后均未发生明显改变,表现出良好的热稳定性。热处理后,高熵合金晶粒细化,析出相减少;热处理温度越高,晶粒细化效果越好。相比于未热处理的试样,热处理后试样的耐腐蚀性能明显提高,并且随热处理温度升高,耐腐蚀性能呈上升趋势。

The NiCrCoTiV high-entropy alloy was prepared by vacuum hot-pressing sintering and heated at 500 ℃, 600 ℃ and 700 ℃ for 18 h, respectively. The effects of different heat-treatments on the phase, microstructure ana corroslon-reslsnng oi me NiCrCoTiV high-entropy alloy were studied in detail by X-ray diffraction, scanning electron microscopy and electrochemical worksta- tion. The experiment results show that after different heat-treatment, the phase of high-entropy alloy did not change significantly, showing excellent high temperature stability. After heat-treatment, the grains of high-entropy alloy are refined and the precipitation phase is reduced. With the increase of heat-treatment temperature, the grain size gradually decreases. After heat-treatment, the cor- rosion resistance of high-entropy alloy gets a great increase. In addition, the corrosion resistance of the high-entropy alloy increases with the heat-treatment temperature rises.