航空用B93铝合金均匀化显微组织分析  

Microstructure Analysis of Homogenized B93 Aluminum Alloy for Aviation

作　　者：姜锋[1] 韦莉莉[1] 蹇海根[1] 郑秀媛[1] 黄宏锋[1] 文康[1] 

机构地区：[1]中南大学材料科学与工程学院,长沙410083

出　　处：《航空材料学报》2010年第2期1-6,共6页Journal of Aeronautical Materials

基　　金：湖南省国际合作项目(2008WK3052)

摘　　要：利用金相显微镜(OM),X射线衍射(XRD)和扫描电镜(SEM)观察了航空用高强B93铝合金铸态及均匀化过程中的显微组织演变,结合不同状态的DSC曲线,发现在均匀化过程中,合金中细长窄小的非平衡相富集区优先发生回溶。在均匀化温度低于350℃时主要是部分过饱和α(Al)固溶体分解析出平衡相η(MgZn2),少量的晶界非平衡低熔点共晶相溶解;均匀化温度高于460℃时平衡η(MgZn2)相、T(AlZnMgCu)相等大部分金属间化合物回溶到基体中,枝晶网络变稀,晶界细化;铸态组织中Cu元素偏析严重,随着均匀化温度的升高,网状连续的富Cu晶界相Al6(CuFe)部分溶解断开,但在均匀化过程并不能完全消除;航空用B93铝合金最佳均匀化工艺为460℃/24h。The as-cast microstructure of high-strength B93 aluminum alloy used in airplane structure and the evolvement of the microstructure during homogenization have been studied by optical microscopy （OM）,X-ray diffraction （XRD） and scanning electron microscopy （SEM）. Combined with the DSC curve of different conditions,the slender and narrow non-equilibrium phase enriched zones were found to re-dissolution first during the homogenization. When the homogenization temperature is below 350℃,the supersaturated solid solution decomposes,equilibrium phase η（MgZn2） precipitates and a spot of non-equilibrium low melting point eutectic phases in grain boundary dissolve. When the temperature is above 460℃,most of the intermetallic compound such as the η（MgZn2） phase,T（AlZnMgCu） phase dissolve back into the matrix,the dendritic network become sparse and the grain boundary become thinner. The Cu element segregates seriously in the ingot. With the homogenization temperature increasing,the continuous reticulation Cu grain boundary phase Al6 （CuFe） dissolves and breaks. However,these phases do not dissolve completely. The optimum homogenization process of B93 aluminum alloy is 460℃ for 24h.

关 键 词：AL-ZN-MG-CU合金 均匀化 显微组织 

分 类 号：TG113[金属学及工艺—物理冶金]