Parametric Assessments of Self-Healing Characteristics in AA2014–NiTi-Based Metallic Composites through Destructive and Nondestructive Evaluation

Abstract

In the current scenario, self-healing nature of an aluminium based composites is an important aspect to be explored. Due to the weldability limitations in nonferrous metals, an attempt to explore the self-healing characteristics in Al alloys was performed. AA2014 reinforced with Ni–Ti wires with different input levels was considered for parametric study. The primarily objective of this research work is to determine the input responses influencing self-healing nature assessments. Specimens with different Shape memory alloy (SMA) vol %, specimen size and SMA wire diameter were fabricated for analysis. Further, Taguchi orthogonal columns of L8 (4^1 2^3) array technique was implemented to study the observations from different experimental runs. Healing temperature (i.e., 600°C) was such selected that it could take the advantage of compositional healing of the matrix. The yield point damaged specimens through bend test were thermally treated at different healing durations in a furnace to activate healing. Through destructive and nondestructive evaluation (subsurface defects) results shows that a maximum of 81.01% of recovery in crack width, recovery in ductility to about 32.61%, 74.86% of recovery in crack depth, and 44.18% of recovery in flexural strength was obtained after healing. Healing duration plays a significant role in controlling the recovery of mechanical and healing properties of the composites. It was observed that to attain higher mechanical properties (i.e., flexural strength and ductility) moderate healing duration is favorable. Whereas, for healing properties (i.e., crack width and crack depth) exposing to higher healing duration is preferred for higher recovery in damaged crack width and crack depth.