Creep Mechanism in Several Grades of Aluminum at Low Temperatures

DOI DOI IR IR Web Site View 2 Remaining Hide 2 Citations 21 References Open Access
  • Matsunaga Tetsuya
    Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency
  • Sato Eiichi
    Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency

Bibliographic Information

Other Title
  • 低温における純アルミニウムのクリープ機構に対する純度の影響
  • テイオン ニ オケル ジュンアルミニウム ノ クリープ キコウ ニ タイスル ジュンド ノ エイキョウ
  • Creep mechanism in several grades of aluminum at low temperature

Search this article

Description

Creep tests were performed at less than 0.4 Tm (Tm is the melting temperature) for 99.999, 99.57 and 99.52% aluminum with several grain sizes in the range of 50–330 µm. These Al materials show remarkable creep behavior with an apparent activation energy (Q) of 30 kJ/mol, a stress exponent of 4, and a grain-size exponent of zero, and with a larger creep rate with increasing purity. These parameters resemble those of conventional dislocation creep, which is rate-controlled by the usual diffusion processes, except for the extra-low Q value. This means that a non-diffusional process affects the steady state deformation in this temperature region. Transmission electron microscopy revealed the development of a cell structure in the steady state and dislocations without any tangles in the cell interiors. Therefore, because the rate-controlling process could not occur inside of the cells, dislocation annihilation occurred through cross slip around the cell walls. According to these creep parameters and microstructural observations, the observed creep region is suggested to be a new creep region occurring through a non-diffusional process within the existing deformation mechanism map of Al at less than 0.4 Tm.

Journal

  • MATERIALS TRANSACTIONS

    MATERIALS TRANSACTIONS 54 (12), 2202-2208, 2013

    The Japan Institute of Metals and Materials

Citations (2)*help

See more

References(21)*help

See more

Keywords

Details 詳細情報について

Report a problem

Back to top