ZrN-ZrB2纳米复合材料的高压制备及性能表征

 以金属锆粉（Zr）和六方氮化硼粉（h-BN）为原料，结合高能球磨和高温高压合成技术，制备出了ZrN-ZrB₂纳米复合材料。利用X射线衍射、透射电镜和拉曼光谱等测试手段，对材料的结构和合成规律进行了研究。结果表明，高能球磨过程中只合成出了ZrN_x，没有出现ZrB₂，从N、B原子与Zr进行固态反应的热力学和动力学方面分析了原因。利用Zr与BN粉球磨10 h后的混料，在压力为5 GPa、温度为1 300 ℃的条件下，制备出了具有高致密度的ZrN-ZrB₂纳米复合材料。其维氏显微硬度（17 GPa）、热膨胀系数（7.57×10^-6 ℃^-1）和电阻率-温度系数（8.846×10^-4 ℃^-1）等材料参数的测量结果表明，ZrN-ZrB₂复合材料是一种集优良的力学、热学和电学性能于一体的纳米复合材料。

High-Pressure Synthesis and Properties Characterization of ZrN-ZrB2 Nanocomposites

Combining high-energy ball milling and high-pressure high-temperature technique, high-dense ZrN-ZrB₂ nanocomposites have been synthesized using Zr and h-BN powders as raw materials. The structures of product materials were studied through X-ray diffraction, high resolution transmission electron microscopy and Raman spectroscopy measurements. The result showed that only ZrN_x can be synthesized during mechanical alloying process, which can be explained by the thermodynamics and kinetics of reaction of Zr atoms with N and B atoms. ZrN-ZrB₂ nanocomposites synthesized at 5 GPa and 1 300 ℃ using 10 h ball-milled powder mixture show excellent mechanical and electrical properties. The microhardness, thermal expansion coefficient and thermal coefficient of resistivity of ZrN-ZrB₂ composites are 17 GPa, 7.57×10^-6 ℃^-1 and 8.846×10^-4 ℃^-1, respectively.