Experimental and numerical study of the influence of induction heating process on build rates Induction Heating-assisted laser Direct Metal Deposition (IH-DMD)

Direct Metal Deposition (DMD) technology proves advantageous in complex and precise component fabrications. Nevertheless, the typical productivity rate of the DMD process is not sufficient for fabricating large components. In this paper, the induction heating (IH) technique is presented to address this issue by assisting the DMD process by increasing the build-up rate. For this purpose, the influences of different laser processing and induction heating factors are investigated to provide the information required for designing a suitable IH setup that is capable of integrating into the DMD process. Furthermore, a finite element simulation of IH is carried out using the COMSOL software package and the results are accordingly verified against experimental data. This helps design a Hybrid Induction DMD (IH-DMD) process by identifying a correlation between induction parameters and generated heating temperature on the component surface. This paper presents the implementation setup of IH-DMD discusses its limitations. In a final setup, deposition of Inconel 625 powder material on the structure steel 5235 with an IH-DMD process is examined to show the improvement gained. This includes different powder feed rates, scan speeds, and spot diameters. The results demonstrate the important role of the coil profile, magnetic flux concentrator, coupling gap, electric current in the coil, and coil shield to achieve a sufficient heating rate and stable IH-DMD coating process. The deposition rates and clad geometry are characterized. By employing IH-DMD, the coating deposition can be improved by a factor of three.