退火石墨/铝复合材料热物理性能

Thermophysical properties of annealed graphite/6061 aluminum alloy composites

随着电子器件热流密度的不断增加,热聚集产生的热点问题严重影响电子器件性能和应用,急需开发高效热扩散材料。采用真空热压烧结工艺制备了以6061铝合金为基体材料,退火石墨(Annealed pyrolytic graphite,APG)为导热组元的高导热复合材料。探究了退火石墨表面Ti元素的改性处理对退火石墨/铝复合材料的微观结构、界面结合状况的影响规律,研究讨论了退火石墨/铝层厚比对复合材料整体热、力性能的影响。结果表明,经Ti元素改性处理的退火石墨材料与铝之间形成了干净、紧密结合厚度在400 nm的Al−Ti−C界面。当Al∶APG∶Al的层厚比为1∶3∶1时,复合材料面内方向热扩散系数达901 mm^(2)·s^(−1),所承载最大抗弯强度为141 MPa,具有优异的综合性能。

As the heat flux density of electronic devices continues to increase,the hot spots caused by heat accumulation seriously affect the performance and application devices.In this study,annealed graphite(APG)/6061 Al with different graphite layer thickness ratios were prepared using vacuum hot-press method.To enhance the wettability between the annealed graphite and aluminum alloy,annealed graphite was coated with a thin layer of titanium by vacuum micro-evaporation plating,which proved to be effective and efficient.The influence of titanium modification on the microstructure and interface bonding of annealed graphite/aluminum composites was discussed,and the effect of the annealed graphite/aluminum layer thickness ratio on the overall thermal and mechanical properties of the composite was studied.Similarly,the results show that a 400 nm thick interface layer is formed between the annealed graphite and aluminum,and the directionally annealed graphite material modified by titanium is in close contact with aluminum.As the thickness ratio of each phase of Al∶APG∶Al is 1∶3∶1,the composite material has a thermal diffusion coefficient of 901 mm^(2)·s^(−1) in the in-plane direction and the maximum flexural strength of the composite material is 141 MPa.