Relationship Between Aluminum-Rich/Intermetallic Phases and Microhardness of a Horizontally Solidified AlSiMgFe Alloy

Materials Research

关键词: Solidification process;    Unsteady-state heat flow;    Intermetallic phases;    Microhardness;    AlSiMg alloys;   

DOI  :  10.1590/1980-5373-mr-2018-0365

来源: DOAJ

【 摘 要 】

An experimental study with an A356-AlSiMgFe alloy was developed to evaluate the microhardness performance in the microstructure resulting of an unsteady-state horizontal solidification process. The Al-7wt%Si-0.3wt%Mg-0.15wt%Fe alloy was elaborated and directionally solidified in a water-cooled horizontal solidification device. In order to experimentally determine the cooling and growth rates (VL and TR, respectively), a thermal analysis was also conducted during solidification. Microstructural characterization by optical microscopy, SEM/EDS elemental mapping and microanalysis of the punctual EDS compositions allowed to observe the presence of an Al-rich dendritic phase (Al(α)) with interdendritic phases second composed of an eutectic mixture: Al(α-eutectic) + Si + Al8Mg3FeSi6(π) + Mg2Si(θ). Furthermore, the dendritic microstructure was characterized by measuring the secondary dendritic spacings (λ2) along the horizontally solidified ingot. Higher HV values were observed within the eutectic mixture.

【 授权许可】

Unknown