Influence of Fe on the microstructure and mechanical properties of low Al-SI alloys. (2018)

• Record Type: Journal Article
• Authors: Pancho, Antonio; Díaz, Carlos; Sotomayor, Oscar
• Is Part Of: International journal of microstructure and materials properties. Volume 13:Number 5(2018)
• Page Start: 317
• Page End: 330
• Publication Date: 2018
• Subjects: Fe influence on AL -- β phase -- A356; Microstructure -- Periodicals; Materials -- Properties -- Periodicals; 620.11299
• Languages: English
• ISSNs: 1741-8410

Abstract

The present study investigates the influence of iron (precipitation of Fe-rich phases) on microstructure, ultimate tensile strength, elongation after fracture and hardness of the aluminium alloy A356, for which metallographic analysis and testing of mechanical properties were performed for iron weight percentages of 0.5, 0.8 y 1%. Phases identification was carried out by X-ray diffraction, which revealed the precipitation of β iron intermetallic phase of stoichiometry Al5 FeSi and monoclinic crystal structure. Cooling rate (0.45°C/s) for sand mould was calculated through secondary dendrite arm spacing whose average length was 62.75 μm. Microhardness measurements showed the hard nature of the β phase, which produced a general increase on the alloy's hardness. The tensile strength reduced slightly (~11% for 1 wt. % Fe) unlike the fracture elongation (ductility) which suffered greatly reduces with iron increase (~54% for 1 wt. % Fe).