High-temperature mechanical properties of cast Al–Si–Cu–Mg alloy by combined additions of cerium and zirconium

• Autor(a) principal: Bevilaqua, William Lemos
• Data de Publicação: 2020
• Outros Autores: Stadtländer, Antônio Ricardo, Froehlich, Andre Ronaldo, Lemos, Guilherme Vieira Braga, Reguly, Afonso
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/210469
• topic: Ligas de alumínio; Altas temperaturas; Propriedades mecânicas; Cério; Zircônio; High temperature; Mechanical properties; Cerium; Zirconium

The main aim of this work is to investigate the effects of combinative Ce and Zr additions (0.3 wt% Ce+0.16 wt% Zr; 0.3 wt% Ce+0.27 wt% Zr and 0.3 wt% Ce+0.36 wt% Zr) on the microstructure and mechanical properties in cast Al–Si–Cu–Mgalloy. The microstructures features were investigated by optical microscope, scanning electron microscope and hardness measurements. The microstructural analysis has shown that the increase of Ce and Zr contents increases the volume fraction of intermetallics formed during the solidification leading to grain refinement and changes in silicon morphology of the as-cast microstructure. The intermetallics formed do not dissolve during the solution heating treatment (T6). The mechanical behavior at room and high temperatures (175, 210, 245 and 275 °C) was determined from uniaxial tensile tests. The high thermal stability of Al–Si– Cu–La–Ce and Al–Si–Zr–Ti–Mgphases found in microstructure, in particular for the alloy containing 0.3 wt% Ce+0.27 wt% Zr, is responsible for the increase to 6.7% and 5.1% the ultimate strength at 210 °Cand 275 °Crespectively, compared with the standard alloy.