Development of elasto-viscoplastic constitutive equation for Al-Mg alloy with tensile test in partial solidification

Ryosuke Takai, Akira Matsushita, Shogo Yanagida, Koichiro Nakamura, Makoto Yoshida

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


In order to predict the hot tearing during DC casting by using thermal stress analysis, constitutive equations in both solid-liquid coexisting and below solidus of alloy are inevitable. However, previous constitutive equations used in hot tearing predictions have no less than one problem as follows. (1) Testing methods of obtaining material constants weren't appropriate. Firstly, elastic strain reversibility was unconfirmed. Secondary, flat distribution of temperature in gauge length of specimen wasn't guaranteed. Thirdly, strain was measured from not local strain but cross head displacement. Fourth, the melt-back phenomenon was unavoidable in partial melting method which was caused by homogenization of segregation structure. (2) Temperature dependence of strain rate sensitivity of stress wasn't considered. (3) Some material constants were not obtained experimentally but guessed. In this study, elastoviscoplastic constitutive equations(Hooke's and Norton's laws)for both partial solidification and below solidus were developed. In order to obtain material constants experimentally, two tensile tests which the problem (1) was solved were conducted using Al-5mass%Mg alloy. They were partial solidification tensile tests(above solidus) and high temperature tensile test with high frequency induction (below solidus). Then, temperature dependence of elastic, viscoplastic properties were investigated and material constants were obtained. Furthermore, they were compared with other previous testing methods.

Original languageEnglish
Pages (from-to)310-317
Number of pages8
JournalKeikinzoku/Journal of Japan Institute of Light Metals
Issue number9
Publication statusPublished - 2013 Nov 18


  • Aluminum alloy
  • Direct-chill casting
  • Elasto-viscoplastic constitutive equation
  • Hot tearing
  • Solidification

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry


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