作　　者： ; ; ; ; ; ;

机构地区： 中南大学材料科学与工程学院

出　　处： 《轻合金加工技术》 2009年第11期51-55,共5页

摘　　要： 采用硬度、电导率测试、X射线衍射物相分析、扫描电子显微分析和透射电子显微分析技术,研究了不同均匀化处理条件下铝-锌-镁-钪合金组织和性能的变化规律,讨论了该铸态合金不同均匀化处理条件下显微组织结构演变与合金硬度和电导率之间的关系。结果表明,铝-锌-镁-钪铸态合金由α(Al)基体和少量T(Mg32(Al,Zn)49)相组成。铸态合金组织固溶体过饱和程度较高,合金硬度较高,电导率较低;随均匀化温度的升高,亚稳的过饱和固溶体先分解析出大量T相,后逐步回溶入基体固溶体中,基体固溶度先降低后增加,合金硬度先降而后升,电导率则先升而后降。更高温度下均匀化,晶粒粗化,合金硬度又下降。确定合金铸锭的理想均匀化工艺参数为470℃24 h。 The microstructures and properties of as-cast Al-Zn-Mg-Sc alloy at different homogenization treatment condition were studied using hardness and electrical conductivity measurement,XRD,SEM and TEM analysis.The correlation between hardness,electrical conductivity and the evolution of microstructure was discussed. The results showed that the phases in the as-cast Al-Zn-Mg-Sc alloy were α（Al） and T（Mg32（Al,Zn）49）.The higher degree of super saturation in the as-cast alloy leaded to the higher hardness and lower electrical conductivity.When the homogenization temperature increased, the super saturation solid solution decomposed and equilibrium phases T precipitated at the beginning, then were dissolved into the solution matrixes, the degree of super saturation in the matrixes decreased firstly, and then increased, so the hardness decreased at the beginning, then increased and electrical conductivity increased firstly, and then decreased. When the homogenization temperature increased fuither, the grain size grew up and hardness of the alloy decreased again. The appropriate homogenization treatment processing was determined to be 470℃ for 24 h.

关 键 词： 铝 锌 镁 钪合金 均匀化处理 布氏硬度 电导率

领　　域： [金属学及工艺] [一般工业技术] [金属学及工艺]