采用先驱体浸渍裂解工艺制备无界面、SiC、PyC和PyC/SiC等界面相SiC/SiC复合材料, 研究了SiC/SiC复合材料的微观结构及静态力学性能, 并通过强迫振动法系统分析了界面相对复合材料内耗行为的影响。研究结果表明, 引入界面相有效改善了复合材料的微观结构及力学性能, 并降低了复合材料的内耗。其中, PyC/SiC复相界面中亚层SiC限制了PyC界面相与纤维的结合及塑性形变, 提高了复合材料的力学性能; 同时, 界面相对SiC/SiC复合材料内耗行为有显著影响, 材料内耗水平与界面剪切强度成反比。对比50和350 ℃时的材料内耗变化率发现, 随界面剪切强度增大, 材料内耗呈降低的趋势, 且含有PyC的PyC/SiC界面复合材料具有较低的内耗变化率, 说明PyC/SiC复相界面的SiC/SiC复合材料更适于高温振动环境。

The increase in both power and packing densities in power electronic devices has led to an increase in the market demand for effective heat-dissipating materials with a high thermal conductivity and thermal expansion coefficient compatible with chip materials while still ensuring the reliability of the power modules. Metal matrix composites, especially copper matrix composites, containing carbon fibers, carbon nanofibers, or diamond are considered very promising as the next generation of thermalmanagement materials in power electronic packages. These composites exhibit enhanced thermal properties, as compared to pure copper, combined with lower density. This paper presents powder metallurgy and hot uniaxial pressing fabrication techniques for copper/carbon composite materials which promise to be efficient heat-dissipation materials for power electronic modules. Thermal analyses clearly indicate that interfacial treatments are required in these composites to achieve high thermal and thermomechanical properties. Control of interfaces (through a novel reinforcement surface treatment, the addition of a carbide-forming element inside the copper powders, and processing methods), when selected carefully and processed properly, will form the right chemical/ mechanical bonding between copper and carbon, enhancing all of the desired thermal and thermomechanical properties while minimizing the deleterious effects. This paper outlines a variety of methods and interfacial materials that achieve these goals.

本文对锂电池中负极材料表面固体电解质膜(SEI膜)的SERS谱进行了研究:极化低电位下对贵重金属的研究表明,非水电解质溶液中痕量水的存在将对SEI膜产生重要影响.在微量水存在的情况下,RCOCO₂Li不是SEI膜的稳定成份,Li₂CO₃、LiF、LiOH或LiOH.H₂O等物种才是其稳定组成.进一步的研究表明:SEI膜的某些谱带具有不同的光吸收特性;它是对外界条件非常敏感的一种表面膜.通过对比分析,SEI膜的特征谱带得到了进一步归属,并对其形成机理做了讨论.