Fabrication of SiC/aluminum-silicon alloy composite from rattan bio-charcoal

• Main Authors: Xiao-Wen Lo, 羅小雯
• Other Authors: Yung-Jen Lin
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/dz3d7a

碩士 === 大同大學 === 材料工程學系(所) === 95 === The purpose of this research is to fabricate ceramic/metal composite material from rattan. Rattan was first carbonized in Ar to form charcoal. Then proper amount of Si powder and pieces of aluminum alloy were put into the alumina crucibles with the charcoal. After heat-treatment in Ar and at high temperature, composites of silicon carbide/aluminum-silicon alloy could be obtained. The results of the experiments showed that silicon carbide with the structure of rattan could be produced after reaction at 1500. The porous ℃silicon carbide preserved the structure of the rattan and was made up of three kinds of interconnected holes with the diameters of 250µm, 6-20µm, and 3µm, respectively. The porous silicon carbide after heat-treatment at 1500 for 16℃ hours had bulk density 1.51g/cm3, open porosity 44±1%, specific surface area 5.5 m2/g, compressive strength 44±2MPa, and flexural strength 13±5 MPa. As for the fabrication of SiC/Al-Si composites, the heat-treatment temperatures ranged from 1300~1500.℃℃ The initial proportion of 2024 aluminum alloy and silicon ranged from Al-10at%Si to Al-30at%Si. During the high temperature reaction, Si reacted to form SiC and Si-Al alloy melted to infiltrate into the porous SiC. However, at higher temperature and less silicon concentration, aluminum carbide would form. The result of this research indicated that the proper conditions for SiC/Al-Si composite fabrication without noticeable aluminum carbide was 1400and Al℃-20at%Si. Under such conditions and heat-treatment for 5 hours, the bulk density of the sample was 2.27 g/cm3, the open porosity was 19±1%, the compressive strength was 316±5MPa and the flexural strength was 138±5MPa. Furthermore, it was also noted that intergranular fracture was the main feature of the composite material during fracture.