Phase Equilibria in the Ag-Ni-Sn System: Isothermal Sections

Abstract

The ternary system Ag-Ni-Sn is one of the constituents of the quaternary system Ag-Cu-Ni-Sn, which is of interest for the investigation of the interactions of Ag-Cu-Sn solder alloys with Ni as a substrate. Until now, only limited research has been done on the Ag-Ni-Sn system, especially in the (Ag,Ni)-rich part, most probably due to experimental difficulties caused by the monotectic reaction in the Ag-Ni binary system, which extends far into the ternary. In the present work a comprehensive study of the phase equilibria in four isothermal sections of the Ag-Ni-Sn system at 200, 450, 700, and 1050°C was carried out employing X-ray diffraction (XRD), metallography, and electron probe microanalysis (EPMA). No evidence for the existence of a ternary phase was obtained, and, in most cases, ternary solubilities of the binary phases were found to be insignificant. The liquid miscibility gap at high temperatures caused a number of serious experimental problems during sample preparation.

Joining with Reactive Nano-Multilayers: Influence of Thermal Properties of Components on Joint Microstructure and Mechanical Performance

“…e.g., [24]; note that the interaction volume of SEM-EDS is considerably larger than the size of the precipitates found in this study, which prevents the exact determination of the composition by this method). In direct vicinity of the Ag 3 Sn precipitates, small particles associated with an enrichment in Ni and Cu are found, indicating the separate formation of ternary Ni-Cu-Sn intermetallic particles (most likely of the Sn-rich (Ni,Cu) 3 Sn 4 -phase): while a number of mixed Ni-Cu-Sn intermetallics exists in the system Ni-Cu-Sn, the mutual solubility of Ag and Ni/Cu in the respective Sn-intermetallic phases is negligible [21,25,26]. For the minor alloying element In, no clear enrichments could be detected.…”

Interfacial Energy Effect on the Distribution of Ag3Sn in Full Intermetallic Joints

“…Silver was reported to be inert in soldering reactions in the sense that Ag did not become incorporated into the reaction products of the soldering reactions, including Ni 3 Sn 4 , Cu 6 Sn 5 , and Cu 3 Sn . During the reactions, Ag in Sn remained in the form of Ag 3 Sn, even when all the Sn had been consumed .…”

Thin layer in situ XRD of electrodeposited Ag/Sn and Ag/In for low-temperature isothermal diffusion soldering

“…Due to the limited lateral resolution and insufficient spectral resolution between Ag and Sn quantification was not attempted. From recent studies of the ternary Ag-Ni-Sn system [42][43][44]49] it is clear that no ternary compounds exist in this system and that all the binary compounds have very limited solubility of the ternary elements. Based on these findings we conclude that the nickel-tin reaction depletes the z-phase of tin, which results in the gradual formation of the solid solution of tin in silver and explains the small shift of the (101) reflection of the z-phase.…”

“…Binary alloy phase diagram of the silver-indium system [33]. [42] as well as by Schmetterer et al [43,44]. The interpretation of the results on Ag/In is based on the phase equilibria given by Baren [33].…”