Development of an eutectic-based self-healing in Al–Si cast alloy

In this study, a self-healing mechanism was developed by means of melting the eutectic structure for microcrack repair in a hypoeutectic Al–Si cast alloy. The alloy was heated just above the eutectic temperature to provide melting of the eutectic in this mechanism. The melted eutectic Si particles repair the microcrack under appropriate conditions. The microcrack formation was provided by tensile loading in Al–Si alloy tensile bars and then eutectic-based self-healing treatment was performed to ensure microcrack healing. Microcrack healing was monitored by X-ray radiography and microstructural examinations were carried out by scanning electron microscopy. The mechanical properties were investigated by tensile testing before and after the healing treatment. Eutectic-based self-healing treatment provides the healing of some microcracks in the microstructure of hypoeutectic Al–Si cast alloy. Also, 44% of yield strength, 59% of ultimate tensile strength, and 86% of total elongation have been recovered by the eutectic-based self-healing process in Al–Si alloy.