Fabrication of Aluminum Rectangular Twist Waveguides: Experimental Investigation and FEM Simulation

Waveguides, used in electronic industries, are structures for transferring electromagnetic waves. A twist waveguide is a device used to change the polarization of waves. In this study, a process for fabricating an aluminum rectangular twist waveguide was designed and some guidelines were introduced. The preliminary profile was obtained by a forward extrusion process. In order to study the effect of strain hardening, the twisting process was studied for annealed and non-annealed samples after the extrusion process. The results revealed the necessity of annealing the samples before the twisting; otherwise, local deformation would occur. Measuring the applied torque showed that as the process progressed, the required torque for an annealed sample would increase due to work hardening, while for a non-annealed sample the torque would decrease after local deformation. Furthermore, the simulation of twisting process was performed using Deform software. No inconsistency was observed between numerical and experimental results. Moreover, investigating the cross sectional distortion showed an undesirable cross sectional distortion for the unfilled sample whereas the cross section in the sand-filled sample stayed rectangular.