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采用压力浸渗和超高压熔渗法制备不同界面状态的金刚石/铜复合材料,分析界面状态对热学性能的影响,重点研究在-65~125℃和-196~85℃两种热冲击载荷下,循环100周次后材料的热导率和热膨胀系数的变化规律。结果表明:通过添加Cr元素的Dia/CuCr和使用超高压制备的EHV-Dia/Cu,材料的界面状态得到了改善;界面强度的提高,有利于获得高热导率,低热膨胀系数的复合材料。Dia/Cu的热导率仅有459.1 W·m-1·K-1,而EHV-Dia/Cu高达678.2 W·m-1·K-1,Dia/CuCr则为529.7 W·m-1·K-1。-55~125℃的热冲击条件下,Dia/Cu,Dia/CuCr,EHV-Dia/Cu的热导率保持良好的稳定性,变化在2.5%以内。而在-196~85℃的热冲击条件下,Dia/Cu由于界面结合力弱,在热应力的作用下热导率急剧下降;Dia/CuCr和EHV-Dia/Cu则表现出了良好的抗热冲击能力,循环后热导率仅下降3%左右。Dia/Cu和Dia/CuCr的初始热膨胀系数分别为8.45×10-6K-1和6.93×10-6K-1,Cr元素的添加使得界面结合强度提高,低膨胀系数的金刚石对高膨胀系数的基体约束力增加,使得热膨胀系数明显下降。在两种热冲击实验条件下,Dia/Cu的热膨胀系数基本保持不变,Dia/CuCr分别上升6.64%和7.22%。
The different states of diamond / copper composites were prepared by pressure infiltration and ultra-high pressure infiltration method. The influence of interface state on the thermal properties was analyzed. The effects of interface conditions on thermal properties were studied at -65 ~ 125 ℃ and -196 ~ 85 ℃ , The cycle of 100 weeks after the material thermal conductivity and thermal expansion coefficient changes. The results show that the interfacial states of the materials are improved by adding Cr / CrCr and EHV-Dia / Cu prepared by ultrahigh pressure. The interfacial strength of the composites is improved by the increase of interfacial strength, which is favorable for obtaining the composites with high thermal conductivity and low thermal expansion coefficient. The thermal conductivity of Dia / Cu is only 459.1 W · m-1 · K-1, while that of EHV-Dia / Cu is up to 678.2 W · m-1 · K-1 and that of Dia / CuCr is 529.7 W · m-1 · K-1. The thermal conductivities of Dia / Cu, Dia / CuCr and EHV-Dia / Cu were maintained well under the thermal shock conditions of -55 ~ 125 ℃ with the variation within 2.5%. However, under the thermal shock conditions of -196 ℃ to85 ℃, the thermal conductivity of Dia / Cu decreases sharply under the action of thermal stress due to the weak interface bonding strength. Dia / CuCr and EHV-Dia / Cu show good resistance Thermal shock ability, thermal conductivity after the cycle decreased by only about 3%. The initial thermal expansion coefficients of Dia / Cu and Dia / CuCr are 8.45 × 10-6K-1 and 6.93 × 10-6K-1, respectively. The addition of Cr improves the interfacial bonding strength. The low coefficient of expansion Binding increases, making the thermal expansion coefficient decreased significantly. Under the two thermal shock experiments, the thermal expansion coefficient of Dia / Cu remained unchanged, Dia / CuCr increased by 6.64% and 7.22% respectively.