Parametric study on the L-DED process parameters for the production of Fe to Cu Functionally Graded Addi tive Materials

Abstract

The processing of Iron-based alloy (Fe)- Copper-based alloy (Cu) multi-material is a current research challenge, yet valuable for various engineering applications, including tooling, aerospace, power generation, etc. Laser Direct Energy Deposition (LDED) is an innovative manufacturing technique employed in this study to create such Fe-Cu functionally graded materials (FGMs). Fe-Cu hybrid components are gaining prominence due to their synergistic properties, combining the high thermal conductivity of copper with the corrosion resistance and mechanical strength, and hardness of stainless steel. This unique combination enhances their functionality and broadens their applicability across various industrial sectors, providing improved performance and durability. However, direct deposition of copper on stainless steel, such as 316L SS, is difficult due to considerable differences in physical, chemical, and thermo-mechanical properties. Cu and Fe have poor solubility and significant differences in thermophysical properties, making the LDED of Fe-Cu challenging. The implementation of a functionally graded material (FGM) approach is one way to deal with this problem. The current study tackles the fabrication of Fe-Cu FGM using the Cu compositional grading approach, which enables printing a gradient with a smooth transition between pure Fe to pure Cu with a Cu increase of 25% in each section. In addition to a trial of continuous gradient with a Cu increase of 1% in each layer. The thesis starts with a parametric study to evaluate the process parameters (laser power, scan speed, etc.) that enable the printing of homogeneous mixtures with different compositions of Fe-Cu. The optimal process parameters were used to print gradient Fe to Cu thin walls in discrete sections of blended compositions. Ultimately, implementing the optimal process parameters
allowed the extension to 3D components, successfully demonstrating the technology’s capability
to build a 3D demonstrator component and tensile test coupons.
Keywords : Additive Manufacturing, Directed Energy Deposition, Functionally Graded Ma
terial, Build-plate Preheating.

Date of Award	26 Nov 2024
Original language	English
Awarding Institution	Ingénieurs sans frontières Belgique
Supervisor	Michaël Hinderdael (Promotor) & Zoé Jardon (Co-promotor)