Purpose

Overall, selection maps about the extent of the eutectic growth projects the solidification velocities leading to given microstructures. This is because of limitations of most of the set of results when obtained for single thermal gradients within the experimental spectrum. In these cases, associations only with the solidification velocity could give the false impression that reaching a given velocity would be enough to reproduce a result. However, that velocity must necessarily be accompanied by a specific thermal gradient during transient solidification. Therefore, the purpose of this paper is to not only project velocity but also include the gradients acting for each velocity.

Design/methodology/approach

Compilation of solidification velocity, v, thermal gradient, G, and cooling rate, Ṫ, data for Sn-Cu and Sn-Bi solder alloys of interest is presented. These data are placed in the form of coupled growth zones according to the correlated microstructures in the literature. In addition, results generated in this work for Sn-(0.5, 0.7, 2.0, 2.8)% Cu and Sn-(34, 52, 58)% Bi alloys solidified under non-stationary conditions are added.

Findings

When analyzing the cooling rate (Ṫ = G.v) and velocity separately, in or around the eutectic composition, a consensus cannot be reached on the resulting microstructure. The (v vs. G) + cooling rate diagrams allow comprehensive analyzes of the combined v and G effects on the subsequent microstructure of the Sn-Cu and Sn-Bi alloys.

Originality/value

The present paper is devoted to the establishment of (v vs. G) + cooling rate diagrams. These plots may allow comprehensive analyses of the combined v and G effects on the subsequent microstructure of the Sn-Cu and Sn-Bi alloys. This microstructure-processing mapping approach is promising to predict phase competition and resulting microstructures in soldering of Sn-Cu and Sn-Bi alloys. These two classes of alloys are of interest to the soldering industry, whereas manipulation of their microstructures is considered of utmost importance for the metallurgical quality of the product.

中文翻译：

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影响 Sn-Cu 和 Sn-Bi 焊料合金共晶程度的局部凝固热参数

目的

总的来说，关于共晶生长范围的选择图预测了导致给定微观结构的凝固速度。这是因为在实验光谱内针对单个热梯度获得的大多数结果集都存在局限性。在这些情况下，仅与凝固速度相关联可能会给人一种错误印象，即达到给定的速度就足以重现结果。然而，在瞬态凝固过程中，该速度必须伴随着特定的热梯度。因此，本文的目的不仅是投影速度，还包括作用于每个速度的梯度。

设计/方法/方法

提供了感兴趣的 Sn-Cu 和 Sn-Bi 焊料合金的凝固速度 v、热梯度 G 和冷却速率 Ṫ 数据的汇编。根据文献中的相关微结构，这些数据以耦合生长区的形式放置。此外，还添加了在非稳态条件下凝固的 Sn-(0.5, 0.7, 2.0, 2.8)% Cu 和 Sn-(34, 52, 58)% Bi 合金的结果。

发现

当分别分析共晶成分内或周围的冷却速率 (Ṫ = Gv) 和速度时，无法就所得的微观结构达成共识。(v vs. G) + 冷却速率图允许综合分析 v 和 G 对 Sn-Cu 和 Sn-Bi 合金的后续微观结构的影响。

原创性/价值

本论文致力于建立 (v vs. G) + 冷却速率图。这些图可以综合分析 v 和 G 对 Sn-Cu 和 Sn-Bi 合金的后续微观结构的影响。这种微结构加工映射方法有望预测 Sn-Cu 和 Sn-Bi 合金焊接中的相竞争和由此产生的微结构。这两类合金对焊接行业很感兴趣，而对其微观结构的处理被认为对产品的冶金质量至关重要。