Mechanical performance enhancement of wire-arc directed energy deposited tungsten/steel multi-material structures through heat treatments
Year: 2025
Type: article
Abstract: Integrating materials with distinct mechanical and thermal properties into a single structure offers notable performance advantages in demanding engineering applications. Among various techniques, wire-arc directed energy deposition (WAAM) has gained attention for its ability to build complex multi-material components with minimal waste. However, joining tungsten and steel remains challenging due to their mismatched thermal and mechanical characteristics, often resulting in high residual stress and weak interfacial bonding. In this study, we investigated whether post-processing heat treatment could effectively improve the structural integrity of W7Ni3Fe–SS316L bimetallic components fabricated via WAAM. Rather than relying solely on trial-and-error, we used finite element simulations to estimate a suitable heat treatment condition—holding at 900 °C for 120 minutes and cooling at 5 °C/min. The selected condition helped relieve residual stress while also modifying the microstructure: the tungsten alloy showed grain refinement, while the stainless steel exhibited moderate grain coarsening. Mechanical testing revealed a 16% increase in tensile strength, from 521 ± 4 MPa to 602 ± 7 MPa. Notably, after heat treatment, fracture no longer occurred at the interface but within the SS316L region, indicating improved bonding. These findings highlight the value of simulation-guided thermal post-processing in enhancing the performance and reliability of multi-material structures.
Authors: Md Abdul Karim, Mahdi Sadeqi Bajestani, Yongho Jeon, Duck Bong Kim
Language: English
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,640
Award: G2529364477
OpenAlex ID: W7082991036