镀层对金刚石/玻璃复合材料性能的影响

为满足现代电子工业日益增长的散热需求，急需研究和开发新型高导热陶瓷（玻璃）基复合材料，而改善复合材料中增强相与基体的界面结合状况是提高复合材料热导率的重要途径.本文在对金刚石和镀Cr金刚石进行镀Cu和控制氧化的基础上，利用放电等离子烧结方法制备了不同的金刚石增强玻璃基复合材料，并观察了其微观形貌和界面结合状况，测定了复合材料的热导率.实验结果表明：复合材料中金刚石颗粒均匀分布于玻璃基体中，Cu/金刚石界面和Cr/Cu界面分别是两种复合材料中结合最弱的界面；复合材料的热导率随着金刚石体积分数的增加而增加；金刚石/玻璃复合材料的热导率随着镀Cu层厚度的增加而降低，由于镀Cr层实现了与金刚石的化学结合以及Cr在Cu层中的扩散，镀Cr金刚石/玻璃复合材料的热导率随着镀Cu层厚度的增加而增加.当金刚石粒径为100μm、体积分数为70%及镀Cu层厚度为约1.59μm时，复合材料的热导率最高达到约91.0 W·m^-1·K^-1.

Effect of surface coatings on the properties of diamond/glass composites

It is emergent to study and develop new ceramic (glass) matrix composites with high thermal conductivity. Improving the bonding condition of the interface between the matrix and reinforcement is an important way to increase the thermal conductivity of these composites. Based on copper plating and controlled oxidation of diamond particles and Cr-coated diamond particles, diamond reinforced glass matrix composites were successfully synthesized by spark plasma sintering (SPS). Their micro-morphology, interface bonding condition and thermal conductivity were investigated. It is shown that diamond particles are distributed in the glass matrix uniformly, while the Cu/diamond interface and Cr/Cu interface are the weakest bonding interface in the two types of composites, respectively. The thermal conductivity of these composites increases with increasing diamond content. The thermal conductivity of the diamond/glass composites decreases with increasing Cu coating thickness; because of chemical bonding between Cr and diamond particles and Cr diffusion in Cu coatings, the thermal conductivity of the Cr-coated diamond/glass composites increases with increasing Cu coating thickness. When the diamond particle size is 100 μm, the diamond volume fraction is 70% and the Cu coating thickness is 1.59 μm, the Cr-coated diamond/glass composite has the highest thermal conductivity about 91.0 W·m-1·K-1.