Pd-Ag-Sn-In-Zn(Re)合金铸态组织结构研究

The Microstructure of Pd-Ag-Sn-In-Zn(Re) Alloy as Casting

通过硬度测试、X射线衍射(XRD)分析、扫描电镜(SEM)观察和能谱(EDS)分析,研究了含少量Re的Pd-Ag-Sn-In-Zn合金原始铸态和均匀化热处理后的显微组织结构。研究表明,合金在铸态时因为冷却速度慢而形成了第二相,均匀化热处理后形成面心立方结构的单相固溶体,硬度也降低。合金原始铸态组织为枝晶组织,均匀化热处理后的组织成分均匀,无枝晶偏析。均匀化热处理后基体中存在的少量富Re第二相颗粒,可以起到弥散强化的作用。

The related microstructures of a Pd - Ag - Sn - In - Zn （Re） alloy as casting and homogeniza- tion were studied by means of hardness test, X - ray diffraction （ XRD）, scanning electron microscopic （SEM） observations and energy spectrum（EDS） analysis. The results show that second phase precipitates exist in casting condition, single phase face centered cubic （fcc） solid solution is formed and the hardness reduced after high temperature homogenizing treatment. The microstructure of alloy is characterized by the dendrite as casting and the uniformly distributed chemical composition as homogenization. But Re rich second phase particles, which have a dispersion strengthening effect, still exist in the matrix as homogeni- zation.