采用高压高温合成技术(T25)，依据纳米复合强化原理，将纳米孪晶金刚石(nt-diamond)块体高的硬度和断裂韧性与纳米孪晶立方氮化硼(nt-cBN)块体高的热稳定和化学稳定性相结合，制备具有极高硬度(大于300GPa)和断裂韧性(大于30 MPa·m1/2)及良好稳定性的nt-cBN / nt-diamond复合超硬材料；在8-25GPa和800-2200℃的压力温度范围内，研究合成工艺参数对nt-cBN/nt-diamond复合材料相组成和孪晶形态及界面行为的影响规律，确定其合理的相分布和异质界面的结构及化学键特征；精确测定nt-cBN/nt-diamond纳米复合块体的硬度、断裂韧性(弹性极限)和热稳定性以及与过度金属间的化学稳定性，建立nt-cBN / nt-diamond纳米复合材料的性能与微观组织和界面结构的关系，发展制备综合性能极其优异的纳米复合超硬材料新技术。

Based on the principles of the nanocomposite enhanced hardness and elastic modulus, combining the high hardness and toughness of nt-diamond and the high chemical and thermal stabilities of nt-cBN, in the range of pressure for 8-25GPa and temperature for 800-2200℃, nt-cBN/nt-diamond superhard nanocrystalline composite materials with an extremely high Vickers hardness (>300GPa) and fracture toughness (>30 MPa•m1/2) as well as good stability will be prepared by the high temperature and high pressure (T25) synthesis technique. The phase constitution, characterization of chemical bonding and herero-interface structure of nt-cBN/nt-diamond namocomposite will be ascertained. The influence of synthesis pressure and temperature on phase constitution, nanotwinned and heterostructure interface’s behaviours will be investigated. We will also accurately measure the properties of nt-cBN/nt-diamond nanocomposite such as hardness, fracture toughness (elastic limit), thermal stability and chemical stability for transition metals. The relationship between properties and microstructure as well as herero-interface structure of nt-cBN/nt-diamond namocomposite will be shown. Basing on the research results in this project, we should be able to give a new effective method to synthesize nanocomposite ultrahard materials with excellent properties.