Plate-like growth in a eutectic Bi-Ni alloy: effects of morphological microstructure evolution and Bi3Ni intermetallic phase on tensile properties

Autor(es)

Cruz, Clarissa ^[1] ; Lima, Thiago ^[1] ; Kakitani, Rafael ^[1] ; Barros, Andre ^[1] ; Garcia, Amauri ^[1] ; Cheung, Noe ^[1]

Afiliação do(s) autor(es)

^[1] Univ Campinas UNICAMP, Dept Mfg & Mat Engn, BR-13083860 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T; v. 9, n. 3, p. 4940-4950, MAY-JUN 2020.
• Citações Web of Science: 0

Resumo

The development of efficient thermal interface materials (TIMs) has become an emerging demand mainly driven by the continual rise in power dissipation of high-performance microprocessors. In this context, Bi-based alloys are among the promising types of TIMs for electronic packaging applications. However, the influence of the microstructural arrangement on mechanical strength of Bi-Ni alloys remains barely understood. To overcome this issue, this study aims to develop quantitative microstructure features -tensile properties correlations for a Bi-0.28 wt.%Ni alloy solidified in a wide range of cooling rates ((T) over dot). In addition to the phase diagram calculated by the Thermo-Calc software (SSOL6 database) and differential scanning calorimetry analysis, the characterization of the Bi3Ni intermetallic compound is carried out using X-ray diffraction and SEM microscopy with energy dispersive X-ray spectroscopy. Wavy instabilities in the plate -like morphology of the Bi matrix are shown to occur for (T) over dot <= 0.13 C/s. Besides that, more significant variations in yield and ultimate tensile strengths, sigma(y) and sigma(u) respectively, are associated with a certain range of microstructural spacings between Bi plates (lambda) from 47.6 to 135.2 mu m. Hence, Hall-Petch type relations are proposed to describe the variation of both sigma(y) and sigma(u) as a function of lambda. (C) 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC -ND license (http://creativecommens.org/licenses/by-ne-nd/4.02). (AU)

• Processo FAPESP: 17/15158-0 - Caracterização microestrutural e de propriedades na avaliação de ligas para contato térmico interfacial
• Beneficiário: Amauri Garcia
• Linha de fomento: Auxílio à Pesquisa - Regular