Purpose

This paper aims to investigate the creep behaviour of the recently developed Sn–8Zn–3Bi–xSb (x = 0, 0.5, 1.0 and 1.5) low temperature lead-free solder alloys.

Design/methodology/approach

An in-house compressive test rig was developed to perform creep tests under stresses of 20–40 MPa and temperature range 25°C–75 °C. Dorn power law and Garofalo hyperbolic sine law were used to model the secondary creep rate.

Findings

High coefficient of determination R² of 0.99 is achieved for both the models. It was found that the activation energy of Sn–8Zn–3Bi solder alloy can be significantly increased with addition of Sb, by 60% to 90 kJ/mol approximately, whereas the secondary creep exponent falls in the range 3–7. Improved creep resistance is attributed to solid solution strengthening introduced by micro-alloying. Creep mechanisms that govern the deformation of these newly developed lead-free solder alloys have also been proposed.

Originality/value

The findings are expected to fill the gap of knowledge on creep behaviour of these newly developed solder alloys, which are possible alternatives as lead-free interconnecting material in low temperature electronic assembly.

中文翻译：

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锑的添加对低温无铅Sn-8Zn-3Bi钎料合金蠕变行为的影响

目的

本文旨在研究最新开发的Sn–8Zn–3Bi–xSb（x = 0、0.5、1.0和1.5）低温无铅焊料合金的蠕变行为。

设计/方法/方法

开发了一种内部压缩试验台，以在20–40 MPa的应力和25°C–75°C的温度范围内执行蠕变试验。使用Dorn幂定律和Garofalo双曲正弦定律对次级蠕变速率进行建模。

发现

两种模型均获得0.99的高确定系数R ²。研究发现，添加Sb可以使Sn-8Zn-3Bi焊料合金的活化能显着增加，大约为60％至90 kJ / mol，而次级蠕变指数在3-7范围内。改善的抗蠕变性归因于微合金化带来的固溶强化。还提出了控制这些新开发的无铅焊料合金变形的蠕变机制。

创意/价值

这些发现有望填补有关这些新开发的焊料合金的蠕变行为的知识空白，这些焊料合金可能会替代低温电子组件中的无铅互连材料。