Session: 03-02-01: Advanced Manufacturing

Paper Number: 152730

152730 - Enhancing Wire Arc Directed Energy Deposition Outcomes Through Tailored Dwell Time Allocation 

Wire Arc Directed Energy Deposition (WA-DED) is an advanced metal 3D printing technique that uses a metal wire feedstock and an electric arc to deposit material layer by layer. Consequently, the high thermal energy leads to challenges such as thermal accumulation, residual stresses, and structural deformation. To counter the challenges, dwell time, or the pauses between depositing layers, is crucial in WA-DED. However, increasing dwell time can significantly impact the time required to build parts.

This paper presents a simulation study that explores strategies for enhancing WA-DED outcomes by designing interlayer dwell time allocation strategy without increasing the total time required to build parts. The study investigates how different strategies for distributing dwell time across interlayers affect key performance metrics, including thermal accumulation, residual stresses (von Mises stress), and deflection, while maintaining a constant total build time. By adjusting dwell times, the study offers insights into achieving a balance between thermal management, structural integrity and build time.

The simulations are carried out on a thermally calibrated finite element model. In the simulation, a 6-layer single wall structure is deposited using a high-strength steel alloy (ERO120S-G), with 5 interlayer dwell times distributed across four different total build time scenarios. For each total build time scenario, four distinct cases are created by varying the distribution of dwell time between layers. Despite these variations in allocation, the total build time remains the same across all cases, ensuring that the effects of how different dwell time distributions on performance can be effectively captured.

The study evaluates three primary performance metrics: (1) average nodal temperature to assess thermal accumulation, (2) von Mises stress to measure residual stresses, and (3) deflection to gauge mechanical deformation. Across all scenarios, it is observed that the case in which the dwell time is least in initial layers and gradually increases in consequent layers consistently shows the lowest thermal accumulation and residual stress. In contrast, the case which allocates constant interlayer dwell time exhibits higher thermal accumulation and residual stress. Results indicate that increasing the total build time (effect of increasing dwell time across layers) reduces both thermal accumulation and residual stresses. However, increasing the total build time also leads to greater deflection highlighting a trade-off between reducing residual stress and controlling deformation and thermal accumulation.

These findings demonstrate that strategic allocation of dwell time significantly improves thermal and structural outcomes without extending the overall build time. By carefully managing how dwell time is distributed across different layers, manufacturers can optimize thermal accumulation, minimize residual stresses, and control deflection, providing a practical approach for enhancing the performance and reliability of additive manufacturing processes.

Presenting Author: Gehendra Sharma Mississippi State University

Presenting Author Biography: Gehendra Sharma has MS in Mechanical Engineering from the University of Oklahoma. Currently, he is a research engineer at the Center for Advanced Vehicular Systems (CAVS) at Mississippi State University. His research focuses on designing engineered systems under uncertainty, additive manufacturing, and machine learning applications in design.