Multiphysyical Finite Element Simulation of Contour Induction Hardening of Gears

Induction heating has been widely applied in the field of heat treatment of components for the automotive and aerospace sectors, in particular for the hardening of a huge variety of applications. The main advantages of using this technology counts the high level of repeatability achievable in the treated product, together with the high velocity and automation of treatment, factors both able to ensure production efficiency and reduced environmental impact. Nowadays, numerical methods are becoming more and more important as a reference method of analysis, in order to optimize the main parameters of the process, also thanks to the possibility of coupling different physical between them, a result which until a few years ago would not have been possible. The aim of this work is the analysis and numerical modeling of the process of induction hardening of gear wheels for the aerospace industry. In this thesis it will be shown how, starting from the electromagnetic and thermal coupled models, already extensively used in the last years by both the research and the industrial sectors, it is possible to calculate the phase transformations that occur in the steel during the heating and cooling stages. The algorithm developed will be firstly applied on the case of a simple 2D geometry, and then the complexity level will be gradually increased (both from computational and process point of view), applying the algorithm to an induction hardening process of a gear. The numerical results thus obtained will be verified experimentally