Journal of the Korean Society of Mechanical Technology (한국기계기술학회지)

Korean Society of Mechanical Technology (한국기계기술학회)
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Characterization of Extrusion Parts for after Pre-aging Treatment in an Al-4.8Zn-1.3Mg Alloy

안정화 열처리에 의한 Al-4.8Zn-1.3Mg계 합금 압출재 특성 평가

  • Received : 2018.10.24
  • Accepted : 2018.12.04
  • Published : 2018.12.28
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Abstract

In this study, the effect of pre-aging treatment for inhibition of natural aging of Al-4.8Zn-1.3Mg alloy by extrusion process was investigated. Firstly, the as-cast microstructure of Al-4.8Zn-1.3Mg alloy billet and its evolution during homogenization($460^{\circ}C$, $4h+510^{\circ}C$, 5h) were investigated by means of optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), hardness analysis. The as-cast microstructures of Al-4.8Zn-1.3Mg alloy reveal $Mg_2Zn$, $Al_5Cu$, $Al_{13}Cu$ formed between dendrities. After homogenization, MgZn, $Al_4Cu$, $Al_{13}Cu$ phases precipitated into the matrix. In addition, standard deviation of homogenized billet was improved than as-cast billet from 2.62 to 0.99. According to pre-aging($100^{\circ}C$, 1h) Al-4.8Zn-1.3Mg alloy by extrusion process, yield strength and tensile strength deviation improved more than condition by natural aging.

Keywords

Acknowledgement

Supported by : 산업통상자원부

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