Pd-Ni合金及其捕集网的结构变化

摘要

采用扫描电镜(SEM)、微区域电子探针(EPMA)和X射线衍射(XRD)等分析方法研究了Pd-5Ni合金捕集网在回收铂过程中形貌和结构的变化。该过程是由气相沉积(吸附)和扩散—再合金化控制的再结晶过程，并导致Pd(Ni)合金网发生结构再造。原始的Pd(Ni)固溶体转变为Pd(Pt)固溶体，Ni逐渐被氧化形成NiO直至Ni完全消失。Pd(Pt)固溶体晶格常数随Pt/Pd比值增大。在再结晶新的晶面和晶体形成过程中，阶梯式(层状)生长是主要机制；而在新晶体长大过程中，螺旋式生长具有重要作用。%The structure reconstruction of Pd-Ni alloy catchment gauzes in the platinum recovery process in the nitric acid plant was studied by SEM,EPMA and XRD,etc.It is a recrystallization process controlled by the vapour deposition,difussion and realloying mechanism.The initial Pd(Ni) solid solution turned into Pd(Pt) solid solution,and the lattice parameters of Pd(Pt)solid solution increased with increase of the Pt/Pd ratio.In the formation process of the recrystallization crystals,the ladder-like growth is the main mechanism,and in the growing process of the crystals,the screw growth plays an important role.The real recrystallization crystals are of tetrakaidecahedron structure(l4-faced body)made up of quadrilaterals and hexagones,and are grains ranging from several micrometers to tens of micrometers in size.