Effect of Aging Treatment on Microstructural Evolution of Rapidly Solidified Eutectic Sn-Pb Alloy Powders

Jianfeng Yan,Jun Xu,Yingjie Liu,Dezhi Zhu

doi:10.3390/app9030392

Jianfeng Yan, Jun Xu + Show 2 more

Open Access

https://doi.org/10.3390/app9030392

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Abstract

The microstructural stability of rapidly solidified eutectic Sn–Pb alloy solder powders was investigated through aging at room temperature (25 °C) and temperatures of 40 °C–120 °C. The coarsening behavior of the Pb-rich phase both at room and elevated temperatures was observed. The evident coarsening of the Pb-rich phase was detected upon storage after 40 days. At elevated temperatures, a similar sequence of Pb-rich phase coarsening was observed; however, it occurred substantially more quickly. Pb-rich coarsening rate kinetics at different temperatures were estimated using the Arrhenius equation. The apparent activation energy was 45.53 ± 4.23 KJ/mol, which indicates that grain boundary diffusion is a crucial mass transport mechanism controlling Pb-rich phase coarsening under annealing.

Highlights

Eutectic Sn–Pb is the most crucial solder alloy with excellent electrical conductivity, good wettability, acceptable plasticity and low melting point properties [1]
The solidification behavior of Sn–Pb droplets was investigated based on the microstructure and solidification path [10]
Few studies have investigated the microstructural evolution of rapidly solidified eutectic Sn–Pb alloy powders

Summary

Introduction

Eutectic Sn–Pb is the most crucial solder alloy with excellent electrical conductivity, good wettability, acceptable plasticity and low melting point properties [1]. In previous decades, it has been used as a joining material for the packaging and interconnection of electronic components and devices, and as solders for temperature-sensitive components, optoelectronics modules, printed circuit, plumbing and assembly of sheet metal parts [2,3,4]. Few studies have investigated the microstructural evolution of rapidly solidified eutectic Sn–Pb alloy powders. In this study, the microstructures and stability of eutectic Sn–Pb alloy powders generated through atomization were investigated. The Pb-rich coarsening rate kinetics and diffusion mechanism in Sn–Pb alloy powders produced through atomization were discussed

Experimental Procedure

Results and Discussion

Effect of Aging on theSEM

Effect of Heat Treatment on the Microstructure of Solder Powder

Cross-sectional

Conclusions