浇注温度对消失模铸造固-液复合Al-Mg双合金界面层的影响  

Effects of Pouring Temperature on Interface Layers of the Al/Mg Bimetallic Castings Processed by Lost Foam Casting

作　　者：李广宇[1] 樊自田[1] 蒋文明[1] 江再良 刘鑫旺[1] 刘富初[1] 

机构地区：[1]华中科技大学材料成形与模具技术国家重点实验室

出　　处：《特种铸造及有色合金》2017年第5期527-531,共5页Special Casting & Nonferrous Alloys

基　　金：国家自然科学基金资助项目(51375187;51204124);华中科技大学材料成形及模具技术国家重点实验室开放基金资助项目(P2015-09);中央高校基本科研业务费专项基金资助项目(2015MS053)

摘　　要：采用消失模铸造工艺制备了固-液复合Al-Mg双合金,通过光学显微镜(OM)、扫描电镜(SEM)、能谱分析(EDS)和X射线衍射仪(XRD)等研究了浇注温度对Al-Mg双合金界面层的影响。结果表明,随着浇注温度升高,界面层厚度增加。当浇注温度为730℃时,Al-Mg双合金界面层较为致密,且厚度均匀;当浇注温度较低时,Al-Mg双合金界面层存在较多孔隙缺陷;浇注温度较高时,Al-Mg双合金界面层各处厚度不均匀。在不同浇注温度下,Al-Mg双合金铸件界面处都形成了3个不同的反应层,分别是靠近Mg基体侧的Mg17Al12+δ-Mg共晶组织层、中间的Mg_(17)Al_(12)+Mg_2Si层和靠近Al基体侧的Al3Mg2+Mg2Si层。The Al-Mg bimetallic castings were prepared by lost foam casting（LFC）,and effects of pouring temperature on interface layers of the Al/Mg bimetallic castings processed by lost foam casting were investigated by optical microscopy（OM）,scanning electron microscopy（SEM）,energy-dispersive X-ray spectroscopy（EDS）and X-ray diffractometer（XRD）.The results show that thickness of the interface layer of the Al-Mg bimetal alloy is increased with the increase of the pouring temperature.With a pouring temperature of 730 ℃,a compact and uniform interface layer can be observed.When the pouring temperature is less than 730 ℃,there exist porosity defects in the interface layer of Al-Mg bimetallic castings,while the pouring temperature is more than 730 ℃,the thickness exhibits un-even interface layers of Al/Mg bimetallic castings.At different pouring temperatures,all the interface layers of Al/Mg bimetallic castings are composed of three different reaction layers：the Mg17Al12＋δ-Mg eutectic closed to magnesium,the Mg17Al12＋ Mg2 Si in the interface and the Al3Mg2＋ Mg2Si nearby aluminum.

关 键 词：消失模铸造 固-液复合 Al-Mg双合金 界面反应层 

分 类 号：TG249.6[金属学及工艺—铸造] TG146.21[一般工业技术—材料科学与工程]