알루미나입자로 강화된 알루미늄합금 복합재료의 미세조직과 기계적 성질

저자

오*섭, 한창석

게재저널

한국재료학회지 Vol. 23, No. 3 (2013)

키워드

mechanical properties, aluminum-matrix composites, yield stress, temperature dependence, strain hardening rate

개요

The mechanical properties and microstructures of aluminum-matrix composites fabricated by the dispersion of fine alumina particles less than 20 μm in size into 6061 aluminum alloys are investigated in this study. In the as-quenched state,
the yield stress of the composite is 40~85 MPa higher than that of the 6061 alloy. This difference is attributed to the high density of dislocations within the matrix introduced due to the difference in the thermal expansion coefficients between the matrix and the reinforcement. The difference in the yield stress between the composite and the 6061 alloy decreases with the aging time and the age-hardening curves of both materials show a similar trend. At room temperature, the strain-hardening rate of the
composite is higher than that of the 6061 alloy, most likely because the distribution of reinforcements enhances the dislocation density during deformation. Both the yield stress and the strain-hardening rate of the T6-treated composite decrease as the testing temperature increases, and the rate of decrease is faster in the composite than in the 6061 alloy. Under creep conditions, the stress exponents of the T6-treated composite vary from 8.3 at 473 K to 4.8 at 623 K. These exponents are larger than those of the 6061 matrix alloy.

첨부파일

• 29. 오창섭_한국재료학회지(재료23권3호(scopus)).pdf [10,149,903 byte]

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