( 1. 深圳大學 材料科學與工程系 深圳市特種功能材料重點實驗室，
深圳 518060;
2. 廣西大學 材料研究所, 南寧 530004)
摘 要: 采用NiO、 Al和Cr粉末反應熱壓制備了Al2O3/NiCrAl復合材料， NiCrAl合金由NiO還原出來的Ni與添加的Cr和Al反應形成。 制備了不同Al2O3含量的Al2O3/NiCrAl復合材料， 并以Al2O3體積分數(shù)分別為25%、 52.2%和75%的Al2O3/NiCrAl復合材料為過渡層制備了Y穩(wěn)定氧化鋯(YSZ)到NiCrAl合金的功能梯度材料。 X射線衍射分析、 金相觀察、 硬度測量和熱循環(huán)沖擊實驗結果表明： 用該方法制備的復合材料由Al2O3陶瓷相和(Ni, Cr, Al)固溶體組成， 而Al2O3顆粒由NiO與Al原位反應形成， 尺寸細小， 呈彌散分布。 該功能梯度材料經從室溫到1 000 ℃空氣中10次熱循環(huán)后未發(fā)現(xiàn)有裂紋, 表明該方法制備的材料陶瓷相與合金相有良好的相容性、 較高的結合強度、 良好的耐高溫抗氧化及熱循環(huán)沖擊性能。
關鍵字: 反應熱壓法; Al2O3/NiCrAl復合材料; 功能梯度材料
XIE Sheng-hui1, ZHUANG Ying-hong2
（ 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
