Effect of AlTi6 grain refiner on morphology, corrosion and mechanical properties of the commercial purity AA1050 aluminum alloy

Abstract

Studying grain growth and the influences of grain refiners are important to control the mechanical properties and corrosion susceptibility of cast aluminum. Three different types of grain morphologies are possible; namely, columnar, twinned columnar, and equiaxed. In this study, commercial aluminum was melted at 750 °C in the presence of master alloy (AlTi6) with various addition levels (0.5–6 gMaster alloy /kgAl ). Inoculants in the form of master alloys were used to promote the formation of a fully equiaxed grain structure. The grain refiner's effect on the corrosion behavior of aluminum was investigated. An Energy Dispersive X-ray test was carried out to study chemical composition. The effect of AlTi6 on the grain size and distribution of equiaxed grains were investigated. Mechanical testing was performed. Rate of corrosion was carried out to investigate the effect of AlTi6 on aluminum grain size. EDX analysis showed a 99.29% Al level in the commercial purity aluminum alloys. Columnar and twinned columnar grains were successfully suppressed in the presence of 5–6 gAlTi6 /kgAl . Tensile test showed an increase in the yield strength. The corrosion rate of commercial aluminum increased from 3.942 mm/year to 4.537 mm/year in the presence of 5 gMaster alloy /kgAl . Corrosion current density was shown to increase from 0.3983 µ A/cm2 to 0.4584 µ A/cm2 .