摘要
Al-Zn-Mg-Cu alloy is a favorable choice for aerospace applications requiring good combination of strength and toughness, which is greatly influenced by the coarse intermetallic particles. The evolution of intermetallic particles in an Al-Zn-Mg-Cu alloy during heat treatment was studied by field emission gun scanning electron microscopy (FEG-SEM) and X-ray diffractometry(XRD). The results show that there are lamellar eutectic structure (α(Al)+Mg(Zn,Al,Cu)2) and Al7Cu2Fe particles in the solidified structure. The Al7Cu2Fe particles are embedded in the eutectic structure. The content of eutectic structure decreases with the increase of holding time and disappears after 24 h. The size and morphology of Al7Cu2Fe particles exhibit no change during the heat treatment. It is found that the Al2CuMg phase is formed during the treatment at 460℃. A transformation process from the primary eutectic phase Mg(Zn,Al,Cu)2 to Al2CuMg is observed, and the transformation mechanism and kinetics are analyzed. The Al2CuMg constituents form in the primary Mg(Zn,Al,Cu)2 phase, and grow along the eutectic microstructure.
Al-Zn-Mg-Cu alloy is a favorable choice for aerospace applications requiring good combination of strength and toughness, which is greatly influenced by the coarse intermetallic particles. The evolution of intermetallic particles in an Al-Zn-Mg-Cu alloy during heat treatment was studied by field emission gun scanning electron microscopy （FEG-SEM） and X-ray diffractometry（XRD）. The results show that there are lamellar eutectic structure （α（Al）＋Mg（Zn,Al,Cu）：） and Al7Cu：Fe particles in the solidified structure. The Al7Cu2Fe particles are embedded in the eutectic structure. The content of eutectic structure decreases with the increase of holding time and disappears after 24 h. The size and morphology of Al7Cu：Fe particles exhibit no change during the heat treatment. It is found that the AI：CuMg phase is formed during the treatment at 460 ℃. A transformation process from the primary eutectic phase Mg（Zn,Al,Cu）2 to Al2CuMg is observed, and the transformation mechanism and kinetics are analyzed, The AI：CuMg constituents form in the primary Mg（Zn,Al,Cu）： phase, and grow along the eutectic microstructure.
出处
《中国有色金属学会会刊：英文版》
CSCD
2006年第A03期1247-1250,共4页
Transactions of Nonferrous Metals Society of China
基金
Project(2004AA5BG018) supported by the Science and Technology Development Fund of Harbin, China
关键词
金属相
铝
锌
镁
合金
有色金属
Al-Zn-Mg-Cu alloy
eutectic structure
intermetallic particles
phase transformation
