多元低熔点共晶合金Sn16 Bi52 Pb32和In21 Sn12 Bi49 Pb18凝固组织和相组成研究∗

摘要

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.%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 Sn16 Bi52 Pb32(质量分数)合金和 In21 Sn12 Bi49 Pb18(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：Sn16-Bi52 Pb32合金由Bi-(Pb)固溶体相、Sn-(Bi,Pb)固溶体相以及 Pb7 Bi3化合物相组成,具有准规则共晶凝固组织结构。而 In21 Sn12 Bi49 Pb18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。