Evaluation of Electrical and Thermal Properties of Titanium Boride Dispersed Aluminum Composites by Spark Plasma Sintering Process

摘要

As titanium diboride (TiB_2) ceramics has good electrical conductivity, highrnthermal conductivity, low thermal expansion and good resistance for plasticrndeformation at high temperature, it is expected to obtain the high performancernelectrical and thermal materials by combining aluminum (Al). In this study, TiB_2rnparticle dispersed Al composites were fabricated by spark plasma sintering (SPS)rnprocess, and then the effect of the degree of dispersion for TiB_2 particles in compositesrnon the thermal conductivity and the electrical conductivity was investigated. After Alrnpowder was mixed with TiB_2 powder with 20vol% by ball milling in the wet processrnin ethanol and the dry process in atmosphere, TiB_2/Al composite was fabricated byrnSPS process. The microstructure of the composites and the degree of dispersion ofrnTiB_2 particles in the composites prepared by wet process and dry process wasrnestimated. Thereby, TiB_2 particles in the composites by wet process were distributedrnuniformly compared with composites by dry process. The electrical conductivity andrnthe thermal conductivity of the composites prepared by dry process are higher thanrnthat of the composites prepared by wet process. The electrical conductivity andrnthermal conductivity of the composites was affected by the dispersibility of TiB_2rnparticles and porosity of the composites. Particularly, the degradation of the electricalrnconductivity of the matrix by the plastic deformation around the TiB_2 particlesrnaffected to the low electrical conductivity of the composites by wet process.