2D70铝合金铸态及均匀化态的显微组织演变  

Microstructural Evolution of As-cast and Homogenized 2D70 Aluminum Alloy

作　　者：王国军[1,2] 熊柏青[1] 张永安[1] 李志辉[1] 李培跃[1] 

机构地区：[1]北京有色金属研究总院有色金属材料制备加工国家重点实验室 [2]东北轻合金有限责任公司

出　　处：《特种铸造及有色合金》2009年第6期560-563,共4页Special Casting & Nonferrous Alloys

基　　金：科技部科技支撑项目(2007BAE38B06)

摘　　要：采用金相显微镜(OM)、扫描电镜(SEM)、能谱分析(EDS)、X射线衍射物相分析(XRD)、差示量热法(DSC)等方法,研究了2D70铝合金铸态组织的相组成,对比观察了该合金铸态、常规均匀化态、高温均匀化态的显微组织。研究结果表明,该合金铸态组织由Al2CuMg、Al2Cu、Al9FeNi、Al7Cu2Fe、Al7Cu4Ni等相组成。DSC和XRD分析表明,单级均匀化处理后可使Al2CuMg基本熔入合金基体中,然而合金中仍存在部分高熔点共晶相,但其起始溶解温度已提高,这为双级均匀化创造了条件。合金铸锭经双级均匀化后高熔点的共晶相回溶的更充分。铸锭中的Al9FeNi、Al7Cu2Fe、Al7Cu4Ni等相在均匀化处理过程中基本不变。Phase constituent in as-cast microstructure and microstructure of the semi-continuous 2D70 aluminum alloy in as-cast,normal homogenization and high temperature homogenization were observed by optical microscope(OM),SEM(scanning electron microscope),EDS(energy dispersive spectrum),XRD(X-ray diffraction)and DSC(differential scanning calorimetry).The results reveal that as-cast microstructure of the alloy is composed of Al2CuMg,Al2Cu,Al9FeNi,Al7Cu2Fe,Al7Cu4Ni phase,presenting amounts of non-equilibrium eutectic phases.DSC and XRD analysis indicate that after one-step homogenization treatment,Al2CuMg phase can be dissolved into the alloy with the presence of some high melting point eutectic phase,and the initial melting temperature of Al2Cu phase is increased,which provides a base for two-stage homogenization treatment.Eutectic phase with melting point is fully dissolved into the alloy after two-sage homogenization treatment.In addition,change of Al9FeNi,Al7Cu2Fe,Al7Cu4Ni phase in the ingot is not observed during homogenization process.

关 键 词：2D70铝合金 组织 均匀化处理 高温均匀化 

分 类 号：TG290[金属学及工艺—铸造]