Aging behavior of ultrafine-grained Al-Mg-Si-X (X=Cu, Ag, Pt, Pd) alloys produced by high-pressure torsion

Daichi Akama, Seungwon Lee, Zenji Horita, Kenji Matsuda, Shoichi Hirosawa

Research output: Contribution to journalArticle


Age-hardenable Al-Mg-Si alloys containing an additional element of either Ag, Cu, Pt or Pd were processed by high-pressure torsion (HPT) and they were subsequently aged at a temperature of 373 K for up to a total period of 5400 ks. It was found that, in all alloys, the grain sizes after HPT were refined to 300-400 nm and there were significant increases in the hardness through the HPT processing. The hardness was further increased by the subsequent aging treatment, confirming the simultaneous strengthening by grain refinement and fine precipitation. However, the aging behavior was different depending on the alloying compositions. In the Cu-added excess Mg alloy, the hardness increase was large and the higher hardness retained for longer aging time when compared with those of non-added alloys. It was suggested that the precipitation of a few particles within a single grain with the size of a few hundred nanometer contributes to appreciable age hardening.

Original languageEnglish
Pages (from-to)448-453
Number of pages6
JournalKeikinzoku/Journal of Japan Institute of Light Metals
Issue number11
Publication statusPublished - Dec 1 2012


All Science Journal Classification (ASJC) codes

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

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