Abstract
In this study, two identical and two dissimilar materials are conjoined by applying the friction welding method to yield various rods. This investigation's primary focus entails examining the repercussions associated with the heat-affected zone (HAZ) arising from elevated temperatures at the welding interfaces on the propagation of electromagnetic (EM) waves within the resultant structures. The study incorporates the photonic crystal approach in conjunction with Maxwell's equations, and the subsequent solution of the latter is executed using the finite element method. The subdivision of the structures into fifteen elements is predicated upon the assumption of the electromagnetic wave number of the m-th segment, k(m), of discrete segments. The finite element method is then administered to the HAZ regions of the structures, wherein the HAZ is discretised into one, three, and five elements, respectively.