Analysis of Nitinol-Based Self-healing Metal Matrix Composites Produced from A356 Alloy by Various Casting Techniques

A comprehensive evaluation of Nitinol-based self-healing metal matrix composites (SHMMC) has been conducted. The samples are prepared by incorporating Nitinol wires into the matrix of A356 alloy. These SHMMCs are produced by three different manufacturing techniques, namely high-pressure die casting, rheocasting, and clamp technique. The characterization, mechanical properties, and self-healing ability of the SHMMCs have been compared and presented. Mechanical characterization of the SHMMCs includes tensile strength analysis. Additionally, self-healing properties were evaluated by assessing the recovery of damage through artificial cracks. The clamp technique exhibited superior mechanical properties, with higher tensile strength compared to high-pressure die casting and the rheocasting casting technique. The observed variations in mechanical and self-healing properties can be attributed to the microstructural differences and defects induced by the manufacturing techniques. High-pressure die casting resulted in dendrite type of microstructures of alpha aluminum, leading to reduced mechanical properties. The fine-grained and globular microstructure obtained through both rheocasting and clamp technique of casting played a crucial role in enhancing mechanical performance and self-healing capabilities. The highest degree of crack reduction and mechanical performance is exhibited by the samples produced by clamp technique.