Radial bimetallic structures via wire arc directed energy deposition-based additive manufacturing

Abstract

Bimetallic wire arc additive manufacturing (AM) has traditionally been limited to depositions characterized by single planar interfaces. This study demonstrates a more complex radial interface concept, with in situ mechanical interlocking and as-built properties suggesting a prestressed compressive effect. A 308 L stainless core is surrounded by a mild steel casing, incrementally maintaining the interface throughout the Z-direction. A small difference in the thermal expansion coefficient between these steels creates residual stresses at their interface. X-ray diffraction analysis confirms phase purity and microstructural characterization reveals columnar grain growth independent of layer transitions. Hardness values are consistent with thermal dissipation characteristics, and the compressive strength of the bimetallic structures shows a 33% to 42% improvement over monolithic controls. Our results demonstrate that biomimetic radial bimetallic variation is feasible with improved mechanical response over monolithic compositions, providing a basis for advanced structural design and implementation using arc-based metal AM.

Semi-empirical modeling of weaving process for high-quality and property parts in plasma arc directed energy deposition

“…Among the various AM techniques, powder bed fusion (PBF) has been widely studied for producing high-quality small-to-medium scale parts using various kinds of alloys due to its precision and material versatility 1,2,3 . In contrast, plasma arc DED has received less attention despite its potential for producing large-scale parts cost effectively with various materials at high deposition rate, particularly for aerospace, automotive, ship, and military applications 4,5 . This is because the DED process faces technological challenges, such as defects, severe distortions due to residual stress, and relatively poor part quality and accuracy owing to macroscale beads with a low resolution 6 .…”