我国是切削工具、成型模具等动摩擦件的消耗大国。钢件表面附上一层高硬、耐磨、抗腐的金刚石，可发挥各自优势，获得优异的综合性能。目前国内外在改善金刚石涂层的结合强度方面，还仅限于中间层种类的尝试，关于中间层扩散行为对该复合材料成分组织和结合强度的影响仍缺乏系统研究。本项目提出采用WC-Co(Cr)金属陶瓷作为中间层，通过分析CVD过程中间层及相邻界面处C、Fe、Co、Cr等元素的扩散行为，结合计算模拟，建立CVD参数、中间层(成分、厚度、晶粒尺寸)与复合材料(成分组织、力学性能、结合强度)之间内在联系，揭示中间层扩散行为对钢基CVD金刚石涂层材料的成分组织和结合强度的调控机理，达到通过中间层优化实现钢件与金刚石在力学性能和热膨胀系数上良好过渡的目的，为设计综合性能优异的钢基CVD金刚石涂层材料提供实验与理论依据，同时也为使用中、高温CVD技术设计其他陶瓷类涂层提供指导。

China has large consumption of cutting tool, mold and other dynamic friction pieces. Diamond coating is ideal for wear-resistant components and machining applications because its extraordinary properties such as high hardness, wear-resistance and anti-corrosion. Current research mainly focused on how to improve adhersion of diamond coating on steel substrate. Nevertheless, lack of literature reported diffusion behavior of the interlayer, which plays a critical role in determining the adhesion of diamond coating. This project will focus on evolution of interlayer during CVD process and its effects on diamond growth on steel substrate. Adopting WC-Co(Cr) as interlayer, the diffusion and reaction mechanism of C, W, Fe, Co, Cr at the interface is analyzed. In order to prepare Dia/WC-Co(Cr)/steel composite material with good adhesion and low surface roughness, the composition and structure of interlayer will be adjusted to match the mechanical properties and thermal expansion coefficient of steel and diamond. Using various methods to characterize the content, composition and mechanical performance of each layer, connections are built between the structure of interlayer and mechanical properties of diamond-steel composite material. The significance of this project is to propose a novel and effective preparation method for diamond coating on steel substrates with good adhesion and low surface roughness. This idea can be extended to other types of ceramic coating prepared by mid- or high-temperature CVD technology.