Variations in casting temperatures effect of re-melted 6061 aluminum alloy on tensile strength

Abstract

The variation in casting temperature influences the solidification rate of aluminum alloys, which in turn affects the tensile properties of the metal. This experiment aims to investigate the effect of four different casting temperatures on the tensile strength of remelted 6061 aluminum alloy. Cast samples were prepared using a square steel mold, and tensile test specimens were machined according to standard tensile tests. The mold was preheated to 220 °C to prevent thermal shock due to temperature differences between the melt and the mold. The casting temperature variations used for the melt were 700, 750, 800, and 850 °C. Ultimate tensile strength (UTS) shows slight fluctuations with changes in casting temperature, decreasing to approximately 160 MPa at 800 °C before recovering at 850 °C, but these variations are not statistically significant. Yield strength remains relatively stable across the temperature range, with minor fluctuations suggesting minimal effect from casting temperature. Young's modulus increases significantly at 750 °C but decreases slightly at 800 °C, indicating moderate sensitivity to casting conditions while maintaining relatively consistent values overall. The relationship between casting temperature and cooling rate is non-linear, with the cooling rate decreasing to a minimum at 800 °C before rising again. The casting temperature has minimal impact on the tensile strength, yield strength, and Young's modulus of remelted Al 6061 alloy, as indicated by the slight fluctuations in these properties across the tested temperature range.