Wire directed energy deposition of steel-aluminum structures using cold metal transfer process
Rangasayee Kannan, D.T. Pierce, Selda Nayir, Md. R. U. Ahsan, Duckbong Kim, Kinga A. Unocic, Yousub Lee, Sainand Jadhav, Md Abdul Karim, Peeyush Nandwana
Abstract
In this study, a sharp transition from 316L stainless steel to 4043 aluminum alloy was fabricated using wire directed energy deposition (DED) via the cold metal transfer (CMT) process. The CMT process with its inherently low heat input, led to a significant reduction in intermetallic thickness at the bi-material interface compared to blown powder DED technique resulting in superior properties when compared to literature reported values for dissimilar steel-aluminum welds. Thermo-kinetic modeling confirmed that the intermetallic formation is through a classical nucleation and growth mechanism, and the fraction and thickness can potentially be controlled by adjusting CMT process parameters to kinetically arrest or minimize the intermetallic formation. These findings underscore the efficacy of CMT-based wire DED for fabrication of steel-aluminum bi-metallic structures.