Mechanical Properties of Nanometric Particulate Reinforced Aluminum Composites

• Main Authors: Yung-chang Kang, 康永昌
• Other Authors: Sammy, L. I. Chan
• Format: Others
• Language: en_US
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/35467700445544817382

博士 === 國立臺灣大學 === 材料科學與工程學研究所 === 92 === Oxide inclusions on the mechanical properties of the P/M commercial pure Al have been studied in this work, and nanometric particulate reinforced Al matrix composites has also been done. Using the pre-treated powder and different sintering atmospheres, different oxide inclusion contents can be introduced to the aluminum alloy. Equally, via a traditional powder metallurgy technique, nanometric particulates can be introduced to the aluminum matrix. The oxide inclusions raised the mechanical properties in the monolithic system. The nanometric particulates can also significantly improve the mechanical properties in the monolithic system. The 1 vol.% nanometric particulate reinforced pure Al or high strength Al alloy composites exhibit obviously higher yield and tensile strengths than the unreinforced monolithic materials and 10vol.% micrometric particulate reinforced pure Al or high strength Al alloy composites. Therefore, introduced oxide inclusion or added nanometric particulates in the monolithic matrix can produce high strength MMC. However, there are some limitations for using oxide inclusions have to be controlled carefully. In view of these limitations of oxidation method, it is more effective by adding nanometric particulates directly to strengthen materials. However, one must carefully control the dispersion problem. For creep testing of monolith with oxide inclusions and nanometric particulates, the oxide inclusions raised the creep resistance in the monolithic system. Similarly, the nanometric particulates can significantly improve the creep life in the monolithic system. For the origin of threshold stress, fine enough and distributed homogeneously oxide inclusions tend to act as barriers to the mobile dislocations. Nanometric particulates can also be observed. The novel nano-particulate reinforced Al matrix composite has a high potential to replace traditional micrometric particulate reinforced Al matrix composite.