摘要:高熵合金与传统合金不同,没有基体主元素,它是由五种或五种以上的合金元素按照等摩尔的比混合、熔炼而成,其中各个组元的质量分数都在5%-35%之间。高熵合金因其在热力学上的高熵效应、结构学上的晶格畸变效应、性能上的鸡尾酒效应和动力学上的迟滞扩散效应,使其有着优于传统合金的硬度,耐磨,耐腐蚀等性能。
当前高熵合金体系研究均在高温范围内进行。本文主要着力于将高熵的理念用于低温钎料的研究,通过元素设计、冶金熔炼、凝固冷却以及之后的特性表征来研究Sn-Bi-In-Sb-Ge、Sn-Bi-In-Sb-Ag、Sn-Bi-In-Sb-Ga三种合金。利用高频炉对合金进行加热熔炼、水冷冷却;分别用扫描电子显微镜(SEM)结合EDS(能谱分析)对合金组织进行表征,结合X-射线衍射仪(XRD)确定在合金凝固过程中产生的物相;并通过差热分析仪(DSC)来测量合金的熔融特性,表征合金的熔程。进而在合金表征的基础上,分别对铜基底、铝合金镀金基底进行焊接尝试。
根据实验结果可以得到以下结论:合金Sn-Bi-In-Sb-Ge最终形成InSb、Bi、Ge、Sn、Sb、Ge4Sb6六种主要成分;Sn-Bi-In-Sb-Ga最终形成了Bi、InBi、InSb、Sb、Ga、Bi3In5六种主要成分,合金Sn-Bi-In-Sb-Ag最终形成了InSb、Sn、Bi、SnBi、Ag3In、Ag六种主要成分。根据DSC分析出合金Sn-Bi-In-Sb-Ge的熔点为150℃,合金Sn-Bi-In-Sb-Ga的熔点为90℃,合金Sn-Bi-In-Sb-Ag的熔点为145℃。采用回流焊工艺,在380℃下镀金铝镍块表面通过传热扩散焊接在一起。根据焓值计算公式得到合金Sn-Bi-In-Sb-Ga的焓值为2.4。
关键词:低温高熵合金;微观组织;性能;焊接
Abstract:High entropy alloy is different from traditional alloy,there is no matrix master element,It is composed of five or more than five alloying elements, mixed and smelted at equimolar ratios, wherein the mass fraction of each component is between 5%-35%.High entropy alloy because of its high entropy in thermodynamics effect, structure on the lattice distortion effect, the performance of the cocktail party effect and dynamics of hysteretic diffusion effect, which is better than the traditional alloy hardness, wear resistance, corrosion resistance and other properties.
At present, the research of high entropy alloy system is carried out in high temperature range.This paper mainly focus on the concept of high entropy for low temperature solder, the elements of design, metallurgical melting and solidification cooling and subsequent characterization of Sn-Bi-In-Sb-Ge, Sn-Bi-In-Sb-Ag, Sn-Bi-In-Sb-Ga three alloy.The alloy is heated and smelted by high frequency furnace 、 water-cooled cooling;Respectively by scanning electron microscopy (SEM) combined with EDS (EDS) were used to characterize the microstructure. The combination of X-ray diffraction (XRD) determined in the process of alloy solidification phase; and by differential thermal analysis (DSC) to measure the melting characteristics of alloy, alloy melting process characterization.On the basis of alloy characterization, the copper base and aluminum alloy gold base were welded trailly.According to the experimental results, we can get the following conclusions: Sn-Bi-In-Sb-Ge alloy formed six kinds of main components of InSb, Bi, Ge, Sn, Sb, Ge4Sb6; Sn-Bi-In-Sb-Ga eventually formed the six main components of Bi, InBi, InSb, Sb, Ga, Bi3In5, Sn-Bi-In-Sb-Ag alloy, resulting in the formation of InSb Sn, Bi, SnBi, Ag3In, Ag six kinds of main components.According to DSC analysis, the melting point of alloy Sn-Bi-In-Sb-Ge is 150℃, the melting point of alloy Sn-Bi-In-Sb-Ga is 90 ℃ , and the melting point of alloy Sn-Bi-In-Sb-Ag is 145 ℃ .The process of reflow soldering is used to make the gold-plated aluminum and nickel blocks at 380℃. the surface is welded together by heat transfer and diffusion. According to the enthalpy calculation formula, the enthalpy value of alloy Sn-Bi-In-Sb-Ga is 2.4.