Composition, Microstructure And Basic Physicochemical Properties Of Multi-component Low-melting-point Eutectic Alloys

Low-melting-point alloys have a wide range of applications in the fields of processing and manufacturing, phase change energy storage, electronic and electrical automatic control, continuous casting simulation, welding, measurements, and many others. Specifically, eutectic compositions make up a large number of low-melting- point alloys that are exploited because of their desirable features like single melting peaks, excellent operational reliability, and casting fluidity. However, publicly available literatures on low-melting-point multi-component eutectic alloys are rare and outdated. Basic data are not available including the exact melting points and compositions, constituent phases, microstructures and morphologies, melting enthalpies, specific heats, densities, and so on. This lack of information seriously limits the development and application of low-melting-point multi-component eutectic alloys.In this paper, all of low-melting-point multi-component eutectic alloys were synthesized by high vacuum induction melting and basic data were investigated by scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), x-ray diffraction (XRD), differential scanning calorimetry (DSC), and density analysis instrument. It is given explicitly for the first time that microstructures and morphologies, constituent phases and physicochemical properties, such as the melting enthalpy and the exact melting point of the 13 low-melting-point multi-component eutectic alloys in this paper.For the need of environmental protection, multi-component low-melting-point alloys with lesser, even none Pb element or Cd element attract more and more attention in industrial community. In view of this, two new multi-component low-melting-point eutectic alloys:In30Sn10Bi10Zn10 (at.%)? In30Sn15Bi30Cd10Zn15 (at.%), with none Pb content which meet the requirements of the development of environmental protection were designed out, and their microstructures and morphologies, constituent phases and physicochemical properties were also studied. The experimental results are as follows:(1) The microstructure of the In3oSn10Bi10Zn10 eutectic alloy is complex-regular structures and consisted of three phases, i.e., Sn-(In, Bi, Zn) solid solution phase, Zn-(In, Bi) solid solution and BiIn2 intermetallic compound phase and its melting point is 59.32?, and the transformation latent heat is 13.82 J/g. Its density is 7.919 g/cm3.(2) The microstructure of the Sn16B152Pb32 hypoeutectic alloy is complex-regular structures and consisted of four phases, i.e., Sn-(In, Bi, Cd, Zn) solid solution phase, Zn solid solution phase, Cd-(Sn, In, Sn, Bi) solid solution and BiIn intermetallic compound phase and its melting point is 67.80?, and the transformation latent heat is 35.00 J/g. Its density is 8.486 g/cm3.