【摘要】 降低金刚石与铜基体之间的界面热阻是提高金刚石/铜复合材料导热性能的关键。本研究采用盐浴镀在金刚石颗粒表面沉积均匀致密的TiC镀层，并配合真空热压烧结制备高导热的TiC包覆金刚石/铜复合材料。研究表明，在1 000℃的盐浴沉积温度下，通过调控沉积时间能够实现镀层厚度在640～1 050 nm范围内TiC包覆金刚石复合粉体的高效制备。在镀覆金刚石体积分数为30%的条件下，当TiC镀层厚度为690 nm时，复合材料的致密度最高为99.1%，同时具有最高的热导率540 W·m^-1·K^-1。更多还原

【Abstract】 Diamond/copper composites are considered one of the most promising materials for thermal management in high-power electronic devices due to their exceptional thermal conductivity and favorable coefficient of thermal expansion. However,their practical application is severely limited by the poor interfacial bonding between diamond particles and the copper matrix. The significant mismatch in physical and chemical properties,particularly poor wettability and weak adhesion,results in high interfacial thermal resistance. This prevents efficient phonon transport and reduces overall thermal conductivity. Therefore,improving interfacial bonding and minimizing interfacial thermal resistance are critical to enhancing the heat transfer efficiency of these composites. To address this challenge,this study proposes a controllable molten-salt coating technique to deposit a uniform and dense titanium carbide interlayer on diamond surfaces. The goal is to improve interfacial wettability and bonding strength between diamond and copper,thereby enhancing the interfacial metallurgical bonding and improving the overall thermal performance of the composite. The process parameters were optimized through thermodynamic analysis and experimental validation. The optimal deposition condition was determined to be a reaction temperature of 1 000 ℃, which enabled the formation of a continuous TiC layer on the diamond surface. By adjusting the holding time,the coating thickness was precisely controlled within the range of approximately 640–1 050 nm. The phase composition,morphology,and elemental distribution of the TiC coating were characterized using X-ray diffraction,scanning electron microscopy,and energy-dispersive spectroscopy. The results demonstrated that the TiC coating was dense,continuous,and well adhered to the diamond surface. X-ray diffraction confirmed that the coating consisted mainly of the TiC phase,indicating that the carbide reaction occurred completely in the salt-bath system. The growth of the TiC coating followed a dissolution,diffusion,and precipitation mechanism,and the thickness of the coating increased with the reaction time. Subsequently,the TiC-coated diamond powders were mixed with high-purity copper powder and consolidated by vacuum hot-press sintering to fabricate dense diamond/copper composites. The effect of TiC coating thickness on the densification,interfacial structure,and thermal conductivity of the composites was systematically investigated. The results showed that the TiC interlayer significantly improved the wettability between diamond and copper,promoting metallurgical bonding at the interface and resulting in a continuous and stable interface. When the TiC coating thickness was approximately 690 nm and the diamond volume fraction was 30 vol.%,the composite achieved the highest relative density of 99.1% and a thermal conductivity of 540 W·m^-1·K^-1,approaching 98.5% of the theoretical value. Furthermore,the TiC layer acted as an effective diffusion barrier,mitigating thermal stress caused by the thermal expansion mismatch between diamond and copper. In conclusion,this study demonstrates that the molten-salt coating technique is an efficient and controllable method for diamond surface metallization. The TiC interlayer effectively bridges the physicochemical mismatch between diamond and copper,enhancing interfacial bonding and reducing interfacial thermal resistance. The TiC-coated diamond/copper composites exhibited both high density and excellent thermal conductivity. The optimized composite,with a 690 nm TiC coating and 30 vol.% diamond,achieved a thermal conductivity of 540 W·m^-1·K^-1 and a relative density of 99.1%. These findings confirm that interfacial engineering via controlled carbide coatings is a feasible and reliable strategy to improve the thermal transport properties of diamond/metal composites. This research provides theoretical insights and practical guidance for developing next-generation high-performance thermal management materials for power electronics,aerospace systems,and advanced cooling applications.更多还原