多元低熔点共晶合金Sn_(16)Bi_(52)Pb_(32)和In_(21)Sn_(12)Bi_(49)Pb_(18)凝固组织和相组成研究

Microstructure and Phase Composition of Multi-component Low-melting-point Eutectic Alloys Sn_(16)Bi_(52)Pb_(32) and In_(21)Sn_(12)Bi_(49)Pb_(18)

随着环境保护的需要,具有较低Pb含量或不含Pb元素的多元低熔点合金越来越受到工业界的重视和青睐,但是该类合金的组织结构形态、相组成和基本的物理化学数据比较缺乏,不利于其工业化应用。鉴于此,文章对两种具有较低Pb含量的Sn_(16)Bi_(52)Pb_(32)(质量分数)合金和In_(21)Sn_(12)Bi_(49)Pb_(18)(质量分数)合金进行了凝固组织、相组成以及物化性能方面的研究。扫描电镜(SEM)、差示扫描量热法(DSC)、X射线衍射(XRD)等分析测试结果表明:Sn_(16)-Bi_(52)Pb_(32)合金由Bi-(Pb)固溶体相、Sn-(Bi,Pb)固溶体相以及Pb_7Bi_3化合物相组成,具有准规则共晶凝固组织结构。而In21Sn12Bi49Pb18合金由InBi化合物相、PbBi化合物相以及Sn-(Bi,In)固溶体相组成,具有复杂规则的共晶组织形貌。

For the need of environmental protection,multi-component low-melting-point alloys with little or none Pb element attract more and more attention in industrial community.However,basic physical and chemical data of low-melting-point alloys including exact melting points,constituent phases,microstructures and morphologies, melting enthalpies,densities,etc are rare,which limits the development of the low-melting-point alloys.In this pa-per,microstructures and morphologies,constituent phases and physicochemical properties of the multi-component low-melting-point eutectic alloys with less Pb content,Sn16 Bi52 Pb32 （wt%）and In21 Sn12 Bi49 Pb18 （wt%）,were ex-plored.The microstructures were observed by scanning electron microscope （SEM）and the phase analyses were per-formed by energy dispersive spectrometer （EDS）and X-ray diffraction （XRD）.The melting points were detected by differential scanning calorimetry （DSC）.The microstructure of Sn16 Bi52 Pb32 hypoeutectic alloy is quasi-regular struc-tures which consists of three phases,i.e.Sn（Bi,Pb）-solid solution phase,Bi （Pb）-solid solution,and Pb7 Bi3 interme-tallic compound phase.The microstructure of In21 Sn12 Bi49 Pb18 eutectic alloy is complex and regular which consists of three phases,i.e.InBi intermetallic compound phase,PbBi intermetallic compound phase,and Sn-（Bi,In）solid solu-tion phase.