Self-Healing in an Aluminum Alloy Reinforces With Microtubes

For the last decade, many researchers have been working to develop self-healing materials, and have obtained good results in the field of polymers. The research described in this paper applies the concept of self healing to fabricate self healing metal matrix composites, with the aid of models developed by the authors for the manufacturing processes and self-healing behavior. The development of self-healing metals is a novel idea that has not been explored in great detail yet. The concept of self-healing described in this paper consists of controlling a low temperature melting alloy imbedded within a higher temperature alloy to create a self healing composite (SHC). When the SHC is damaged or cracked, heat may be applied to the affected area whereupon the low melting alloy will melt and flow into the crack healing the damage and sealing the crack. This study consists of theoretical analysis, metallurgical design, experimental synthesis and Computational Fluid Dynamics of a self-healing aluminum alloy designed by the authors. The aluminum alloy matrix is reinforced with microtubes of alumina (Al₂O₃) that are filled with a low melting point solder alloy. The objective of the study reported here was to find the influence and efficiency of the solder in healing an aluminum matrix. To check this effect a crack was created in the metal surface, piercing the microtube(s) filled with solder, and then the SHC was heated above the melting point of the solder alloy.