Deformation Properties of Induction Heating Coils Made by 3D Additive Manufacturing Using Electron Beam Melting

Abstract

Conventionally, induction heating coils, the main components of induction hardening equipment, are manufactured using many technologies such as cutting, bending, and brazing in the process to completion. To avoid this time-consuming and costly method, we have applied metal additive manufacturing, which has recently attracted attention as a new manufacturing technology, to manufacturing induction heating coils. By metal additive manufacturing equipment using electron beam melting (EB-AM, shortly), we successfully fabricated pure copper moldings equivalent to oxygen-free copper C1020. Using this molding method, we manufactured two different types of coils, one with less brazing joints, and the other with a complicated inner cooling channel that was difficult for the conventional method. Comparing the results of induction hardening experiments on those coils and the coil manufactured by the conventional method, it was confirmed that the hardening property provided by the EB-AM coils was comparable to the coil of the conventional method. In addition, it was found that the EB-AM coil with less brazing joints showed less deformation after the induction heating process than the coil of the conventional method with many brazing joints. Also, temperature measurements and simulations on the coils during the induction heating process revealed the EB-AM coil showed lower temperature, smaller deformation, and little fluctuation of the air gap between the coil and the workpiece than the coil of the conventional method.