High cooling rate, regular and plate like cells in Sn–Ni solder alloys

• Main Author: Xavier, Marcella G. C.
• Publication Date: 2018
• Other Authors: Silva, Bismarck Luiz, Garcia, Amauri, Spinelli, José Eduardo
• Format: Article
• Language: eng
• Source: Repositório Institucional da UFRN
• Download full: https://repositorio.ufrn.br/handle/123456789/31787
• topic: Microstructure; Sn–Ni; Tensile properties

Broad ranges of cooling rates (urn:x-wiley:14381656:media:adem201701179:adem201701179-math-0001) 0.8–30.5 and 0.4–5.0 K s−1 are attained during directional solidification of eutectic Sn–0.2 wt% Ni and hypereutectic Sn–0.5 wt% Ni alloys, respectively. A reverse high cooling rate cell‐to‐dendrite transition occurs for the eutectic composition and a transition from high cooling rate cells to plate like cells for the hypereutectic alloy. High cooling rate β‐Sn cells are associated with cooling rates >5.5 and >2.7 K s−1 for eutectic and hypereutectic compositions, respectively. A processing diagram, relating the ‘urn:x-wiley:14381656:media:adem201701179:adem201701179-math-0002–Ni content’ space with the microstructural morphology, is proposed. A combination of plate like cells and plate NiSn4 eutectic phase results in higher ductility