通过真空热压烧结制备出高石墨含量的鳞片石墨/铜复合材料。研究了高石墨含量对鳞片石墨/铜复合材料微观结构和性能的影响。结果表明,随着石墨体积分数的增加(72.08 vol.%~93.34 vol.%),复合材料的密度降低(4.07~2.63 g cm^-3);电导率降...通过真空热压烧结制备出高石墨含量的鳞片石墨/铜复合材料。研究了高石墨含量对鳞片石墨/铜复合材料微观结构和性能的影响。结果表明,随着石墨体积分数的增加(72.08 vol.%~93.34 vol.%),复合材料的密度降低(4.07~2.63 g cm^-3);电导率降低(14.71%~2.45%国际退火铜标准);面向热导率先增加后降低,在石墨体积分数为82.6%时,面向热导率达到最大值为663.73 W m^-1K^-1;面向热膨胀系数降低(6.6×10^-6~2.2×10^-6K^-1);抗弯强度降低(42.48~14.63 MPa),抗压强度降低(45.75~20.46 MPa)。鳞片石墨在复合材料中高度取向排列,分布均匀。并对预测复合材料的热导率模型进行修正,发现测量结果和模型预测结果相吻合。展开更多
This paper presents the fabrication of squama-shape micro/nano multi-scale structures and the analysis of the interaction among different-scale structures during the fabrication processes. Well-designed microstructure...This paper presents the fabrication of squama-shape micro/nano multi-scale structures and the analysis of the interaction among different-scale structures during the fabrication processes. Well-designed microstructures made of inverted pyramids and V-shape grooves are fabricated by KOH wet etching. High-dense high-aspect-ratio (HAR) nanostructures are fabricated atop microstructures by an improved maskless deep reactive ion etching (DRIE) process, with an optimized recipe to form micro/nano dual-scale structures (MNDS). Due to the impact of the profile of microstructures on the shape of nanostructures, dissymmetrical (i.e., squama-shape) nanopillars have been formed on the inclined surfaces of microstructures, while the symmetrical nanopillars are formed on the horizontal surfaces with different formation velocities. Furthermore, the optical properties of MNDS are not sensitive to structural parameters of microstructures, making the sample overcome the lithography limitation of conventional processes for photo-devices. Eventually, three-level structures are fabricated by sputtering a gold thin film on the MNDS, and the profile of MNDS is selective in the deposition of gold particles, which is very useful for practical applications.展开更多
文摘通过真空热压烧结制备出高石墨含量的鳞片石墨/铜复合材料。研究了高石墨含量对鳞片石墨/铜复合材料微观结构和性能的影响。结果表明,随着石墨体积分数的增加(72.08 vol.%~93.34 vol.%),复合材料的密度降低(4.07~2.63 g cm^-3);电导率降低(14.71%~2.45%国际退火铜标准);面向热导率先增加后降低,在石墨体积分数为82.6%时,面向热导率达到最大值为663.73 W m^-1K^-1;面向热膨胀系数降低(6.6×10^-6~2.2×10^-6K^-1);抗弯强度降低(42.48~14.63 MPa),抗压强度降低(45.75~20.46 MPa)。鳞片石墨在复合材料中高度取向排列,分布均匀。并对预测复合材料的热导率模型进行修正,发现测量结果和模型预测结果相吻合。
基金supported by the National Natural Science Foundation of China (Grand Nos. 91023045, 61176103)the Key Laboratory Fund(Grant No. 9140C790103110C7903)
文摘This paper presents the fabrication of squama-shape micro/nano multi-scale structures and the analysis of the interaction among different-scale structures during the fabrication processes. Well-designed microstructures made of inverted pyramids and V-shape grooves are fabricated by KOH wet etching. High-dense high-aspect-ratio (HAR) nanostructures are fabricated atop microstructures by an improved maskless deep reactive ion etching (DRIE) process, with an optimized recipe to form micro/nano dual-scale structures (MNDS). Due to the impact of the profile of microstructures on the shape of nanostructures, dissymmetrical (i.e., squama-shape) nanopillars have been formed on the inclined surfaces of microstructures, while the symmetrical nanopillars are formed on the horizontal surfaces with different formation velocities. Furthermore, the optical properties of MNDS are not sensitive to structural parameters of microstructures, making the sample overcome the lithography limitation of conventional processes for photo-devices. Eventually, three-level structures are fabricated by sputtering a gold thin film on the MNDS, and the profile of MNDS is selective in the deposition of gold particles, which is very useful for practical applications.
