硼化物、富Ce混合稀土对再生Al-Si合金中富铁相变质行为的影响  

Effects of Borides and Ce-Rich Mischmetal on the Modification of Fe-Rich Intermetallics in Secondary Al-Si Alloys

作　　者：杨怀德[1] 龙思远[1,2] 朱姝晴 范超[1] 杨承志[1] 

机构地区：[1]重庆大学,重庆400030 [2]国家镁合金材料工程技术研究中心,重庆400030

出　　处：《稀有金属材料与工程》2016年第1期187-191,共5页Rare Metal Materials and Engineering

基　　金：9C省部产学研结合重大专项项目-汽车轻量化构件精益铸造关键技术及产业化集群示范(2012A090300016);山东省自主创新专项计划项目(2012cx60301)

摘　　要：研究了硼化物、富Ce混合稀土对再生Al-Si合金富铁相变质行为的影响。采用光学显微镜(OM)、扫描电镜(SEM)对试样微观组织进行形貌观察,采用X射线衍射分析仪(XRD)、扫描电镜附带的能谱仪(EDS)分别对试样进行相分析与成分分析,利用差分扫描量热仪(DSC)研究相转变温度。研究表明,硼化物可以促进针状β-Fe相向初生α-Fe相转变,且初生α-Fe相尺寸随着硼化物的添加量增加而增大。当硼化物(KBF4)添加量达到1.0%时(质量分数),开始析出汉字状α-Fe相,汉字状α-Fe相以初生α-Fe相为基底形核并长大;富Ce混合稀土不仅可以抑制初生α-Fe相长大,且能抑制汉字状α-Fe相生成。Effects of borides and Ce-rich mischmetal on the modification of Fe-rich intermetallics in secondary Al-Si alloys were studied. Microstructure morphology was observed by optical microscope（OM） and scanning electric microscope（SEM）. Phases and compositions were analyzed by X-ray diffraction（XRD） and energy dispersive X-ray（EDS）, respectively. Phase transition temperature was measured by differential scanning calorimeter（DSC）. It is indicated that borides can prompt transformation from needle-like β-Fe phase to primary α-Fe phase. And the size of primary α-Fe phase increases with more borides addition. When the borides（KBF4） reach 1.0wt%, Chinese script-type α-Fe phase begins to precipitate. Nucleation of Chinese script-type α-Fe phase is based on primary α-Fe phase. Ce-rich mischmetal can inhibit the growth of the primary α-Fe phase and the formation of Chinese script-type α-Fe phase.

关 键 词：富铁相 变质 再生Al-Si合金 稀土 硼化物 

分 类 号：TG146.21[一般工业技术—材料科学与工程]