( 1. 深圳大学 材料科学与工程系 深圳市特种功能材料重点实验室，
深圳 518060;
2. 广西大学 材料研究所, 南宁 530004)
摘 要: 采用NiO、 Al和Cr粉末反应热压制备了Al2O3/NiCrAl复合材料， NiCrAl合金由NiO还原出来的Ni与添加的Cr和Al反应形成。 制备了不同Al2O3含量的Al2O3/NiCrAl复合材料， 并以Al2O3体积分数分别为25%、 52.2%和75%的Al2O3/NiCrAl复合材料为过渡层制备了Y稳定氧化锆(YSZ)到NiCrAl合金的功能梯度材料。 X射线衍射分析、 金相观察、 硬度测量和热循环冲击实验结果表明： 用该方法制备的复合材料由Al2O3陶瓷相和(Ni, Cr, Al)固溶体组成， 而Al2O3颗粒由NiO与Al原位反应形成， 尺寸细小， 呈弥散分布。 该功能梯度材料经从室温到1 000 ℃空气中10次热循环后未发现有裂纹, 表明该方法制备的材料陶瓷相与合金相有良好的相容性、 较高的结合强度、 良好的耐高温抗氧化及热循环冲击性能。
关键字: 反应热压法; Al2O3/NiCrAl复合材料; 功能梯度材料
（ 1. Shenzhen Key Laboratory of Special Functional Materials,
Department of Materials Science and Engineering,
Shenzhen University, Shenzhen 518060, China;
2. Institute of Materials Science, Guangxi University, Nanning 530004, China）
Abstract: The Al2O3/NiCrAl composites were fabricated by NiO, Al and Cr powders using reactive hot pressing method. The NiCrAl alloy with good high-temperature properties was formed by the reaction of extra Al, Cr and the Ni reduced from NiO. The Al2O3/NiCrAl composites with various Al2O3 fraction were successfully fabricated by the proper addition of Ni, Cr, Al or Al2O3 powders. A 5-layer functional gradient material of YSZ-NiCrAl was fabricated using the composites as interlayers. The results from XRD analysis， optical microscope observation, hardness measurement and thermal cycling test show that the composites fabricated by this method consist of Al2O3 phase and (Ni, Cr, Al) solid solution. The Al2O3 grains formed by the in-situ reaction between NiO and Ni are fine and dispersive. No cracking is found in the functional gradient materials after 10 thermal cycles up to 1 000 ℃. The composites and functional gradient material have strong strength, good resistance to wear and thermal shock.
Key words: reactive hot pressing; Al2O3/NiCrAl composite; functional gradient material
