热冲击对金刚石/铜复合材料的热学性能影响  

Influences of Thermal Shock on Thermal Properties of Diamond / Copper Composite

作　　者：白智辉[1] 郭宏[1,2] 张习敏[1] 尹法章[1] 韩媛媛[1] 范叶明[1] 

机构地区：[1]北京有色金属研究总院国家有色金属复合材料工程技术研究中心,北京100088 [2]北京科技大学材料科学与工程学院,北京100083

出　　处：《稀有金属》2013年第5期840-844,共5页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(50971020)资助

摘　　要：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459．1W·m^-1·K^-1，而EHV．Dia／Cu高达678．2W·m^-1·K^-1，Dia／CuCr则为529．7W·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。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％。Different interface states of diamond/copper composites were prepared by pressure Infiltration and EHV Infiltration. The effect of interface state on thermal performance was investigated. The samples were submitted to 100 thermal shock cycles from -65 to 125 ~C or from - 196 to 85 ℃. Thermal properties such as thermal conductivity and expansion coefficient were measured before and af- ter thermal cycles. The results showed that the interfaces states of Dia/CuCr and EHV-Dia/Cu were significantly improved. The im- proved bonding strength would be conducive to obtain a composite material with high thermal conductivity and low thermal expansion coefficient. The thermal conductivity of Dia/Cu was only 459.1 W.m-l＇K-1, while that of EHV-Dia/Cu was up to 529.7 W.m-LK-＇ and the thermal conductivity of Dia/CuCr was 529.7 W＇m- 1.K-1. In the thermal shock test from -55 to 125 ℃, the thermal conduc- tivity of Dia/Cu, Dia/CuCr and EHV-Dia/Cu maintained a good stability, each group changed within 2.5%. In the thermal shock test from - 196 to 85℃, the thermal conductivity of Dia/Cu declined rapidly after 100 thermal cycles because of its weak interface binding strength. However, the Dia/CuCr and EHV-Dia/Cu performed excellent thermal shock resistance, with their thermal conductivity only declined about 3%. The initial coefficient of thermal expansion （CTE） of DiaCu and Dia/CuCr were 8.45 x 10 - K-1 and 6.93 x 10-s K-1 separately. Cr addition improved the interfacial bonding strength. Low CTE of diamond increased constraining force to the high CTE of substrate, so that the CTE decreased significantly. In the two experimental conditions of thermal shock, CTE of DiaCu re- mained stable, Dia/CuCr increased by 6.64% and 7.22%, respectively.

关 键 词：金刚石 铜复合材料 界面 热冲击 热导率 热膨胀系数 

分 类 号：TB333[一般工业技术—材料科学与工程]