Multi-material additive-manufacturing of tungsten - copper alloy bimetallic structure with a stainless-steel interlayer and associated bonding mechanisms

Laser Powder Bed Fusion of Dissimilar Metal Materials: A Review

“…It is worth noting that the micron-sized SS globules and submicro Cu globules distribute within the Cu-rich matrix and SS bands, respectively, due to the liquid miscibility gap in the Fe–Cu system, as shown in Figure 9 c,e [ 93 , 113 ]. This phenomenon is also found at the interface of SS–CuA in LPBF-processed W/316L/CuA [ 94 ].…”

“…Moreover, adding an interlayer can solve the bonding problem between dissimilar materials with a significant melting point difference. Wei et al used an SS interlayer to successfully bond dissimilar copper/tungsten, taking full advantage of the elements’ wetting behaviour and diffusion mechanism [ 94 ]. However, due to the specific limitations of single material usage, most commercially available LPBF machines cannot easily process different metal materials in one step.…”

“…As shown in Figure 6 e,f, the mixing of the elements occurs at the CuA–316L interface, which is excited by the circulating flow, and cracks can be observed. However, no pores or cracks were detected at the 316L/W interface, indicating good hydrophilicity [ 94 ]. The excellent wettability may explain this between Fe/Ni and W, which will be discussed in more detail in Section 5.2 .…”

“…The depth of penetration of the molten metal into the previous layer is determined by favourable wettability and heat transfer [ 158 ]. Due to the large melting point difference and the joining of dissimilar metal materials (e.g., W and Cu), the energy used to melt Cu cannot completely melt the preprinted W. Cu tends to agglomerate into spheres due to surface tension and cannot spread on the W surface, as shown in Figure 13 c,d [ 94 ].…”

Microstructural Variations in Laser Powder Bed Fused Al–15%Fe Alloy at Intermediate Temperatures

“…Metal additive manufacturing (AM) is an advanced manufacturing technology used for fabricating complex-shaped metal/alloy components using computer-aided design [1]. Laser powder bed fusion (L-PBF) is one of the representative metal-AM processes [2] that has been adopted for a considerably lightweight aluminum (Al) alloy series [3,4]. In L-PBF, a scanning laser irradiates the metal/alloy powder that is sequentially bedded on a base plate, which leads to selective melting and subsequent rapid solidification.…”