Two-Zone Microstructures in Al-18Si Alloy Powders

Autor(es)

Spinelli, J. E. ^{[1, 2]} ; Bogno, A. -A. ^[2] ; Henein, H. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Dept Mat Engn, BR-13565905 Sao Carlos, SP - Brazil

^[2] Univ Alberta, Dept Chem & Mat Engn, Edmonton, AB T6G 2G6 - Canada

• Tipo de documento: Artigo Científico
• Fonte: METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE; v. 49A, n. 2, p. 550-562, FEB 2018.
• Citações Web of Science: 3

Resumo

Hypereutectic Al-18 wt pct Si alloy is widely used in automotive industry as a wear-resistant alloy for engine components. However, in the last few years, this traditional composition is being considered for processing by different rapid solidification methods. Positive points include its low thermal expansion and uniform distribution of surface oxides. Nevertheless, the microstructural aspects of Al-Si powders of 18 wt pct Si are still need to be addressed, such as, the eutectic Si morphology, size, and distribution generated by different process conditions during rapid solidification. Based on a detailed quantitative analysis of the microstructures of rapid solidified Al-18 wt pct Si in this work, solidification conditions that yield specific Si morphologies, Si spacing, and thermal cooling conditions are outlined. The focus is determining the solidification conditions that will yield a specified shape of eutectic Si. It is shown that Si morphology is dependent on a combination of growth velocity (based on modified JH model) and temperature gradient. Furthermore, the highest hardness is achieved with globular morphologies of Si. The processing conditions required to achieve these properties are outlined. (AU)

• Processo FAPESP: 16/10596-6 - Atomização por impulso de ligas Sn-Zn e Al-Si: correlações das morfologias e microestruturas formadas com parâmetros de processo
• Beneficiário: José Eduardo Spinelli
• Modalidade de apoio: Bolsas no Exterior - Pesquisa
• Processo FAPESP: 15/11863-5 - Parâmetros da microestrutura de solidificação de ligas multicomponentes Al-Si-Cu, Sn-Bi-Sb e Zn-Sn-Cu e propriedades mecânicas decorrentes
• Beneficiário: José Eduardo Spinelli
• Modalidade de apoio: Auxílio à Pesquisa - Regular