Effect of Si content on microstructure and properties of Si/Al composites
(1. School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081 China;
2. National Key Laboratory of Science and Technology on Materials under Shock and Impact, Beijing 100081, China)
2. National Key Laboratory of Science and Technology on Materials under Shock and Impact, Beijing 100081, China)
Abstract: Si/Al composites with different Si contents for electronic packaging were prepared by spark plasma sintering (SPS) technique. Properties of the composites were investigated, including density, thermal conductivity, coefficient of thermal expansion and flexural strength. The effects of the Si content on microstructure and thermal and mechanical properties of the composites were studied. The results show that the Si/Al composites consist of Si and Al components and Al uniformly distributes among Si grains. The relative density of the Si/Al composites gradually increases with the decrease of Si content and reaches 98.0% when the Si content is 50%. The thermal conductivity, the coefficient of thermal expansion and the flexural strength of the composite all decrease with the increase of the Si content, and an optimal matching of them is obtained when the Si content is 60% (volume fraction).
Key words: spark plasma sintering; Si/Al composite; thermal conductivity; coefficient of thermal expansion; flexural strength