Fe和Si杂质对Al-Zn-Mg-Cu合金淬火敏感性的影响  

Influence of Fe and Si Impurities on the Quench Sensitivity of Al-Zn-Mg-Cu Alloy

作　　者：张新明[1,2] 余翠娟 刘胜胆[1,2] 刘星兴[1,2] 张盼[1,2] 王莹莹[1,2] 

机构地区：[1]中南大学材料科学与工程学院,长沙410083 [2]中南大学有色金属材料科学与工程教育部重点实验室,长沙410083

出　　处：《材料工程》2013年第10期41-47,共7页Journal of Materials Engineering

基　　金：国家973重点基础研究发展计划资助项目(2012CB619500)

摘　　要：采用光学显微镜、扫描电子显微镜和透射电子显微镜等方法,研究了Fe和Si杂质对Al-Zn-Mg-Cu合金淬火敏感性的影响。结果表明:杂质含量的增加降低了合金的淬火敏感性,用硬度表征时最大降低3.29%。随杂质Fe和Si含量的增加,Al7Cu2Fe相和Mg2Si相含量明显增加,消耗了基体中的Cu和Mg原子,合金的过饱和度降低,从而引起合金淬火敏感性的降低;同时粗大的Al7Cu2Fe相和Mg2Si相有利于再结晶核心的形成,增加了合金的再结晶晶粒和(亚)晶界数目,促进慢速淬火过程中η平衡相的析出。过饱和度对合金淬火敏感性的影响大于晶粒结构对合金淬火敏感性的影响。The influence of Fe and Si impurities was investigated quenching by means of end-quenching tests,and microstructure analysis including optical microscopy （OM）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. Results show that the addition of Fe and Si im- purities leads to lower quench sensitivity, decreasing by 3.29% in maximum when characterize by hardness. With increasing the content of Fe and Si impurities, Air Cu2 Fe phase and Mg2 Si phase con- tent increased significantly, thus reducing the solutes concentration of Cu and Mg elements in the ma- trix,reducing the degree of supersaturation, which leads to lower quench sensitivity. AlrCuzFe phases and Mgz Si phases are favorable for recrystallization, but bad for the reducing quench sensitivity. This is attributed to the higher amount of the recrystallization grains and （sub）grain boundaries, which re- sult in more heterogeneous precipitation of η equilibrium phases during slow quenching. The influence of supersaturation on quench sensitivity is bigger than that of grain structures.

关 键 词：Fe和Si杂质 Al-Zn—Mg—Cu合金 末端淬火 淬火敏感性 

分 类 号：TG146.21[一般工业技术—材料科学与工程]