Silver Electroless Finishing of Selective Laser Melting 3D-Printed AlSi10Mg Artifacts

Gold, Silver, and Electrum Electroless Plating on Additively Manufactured Laser Powder-Bed Fusion AlSi10Mg Parts: A Review

“…However, the associated published technological information is limited as a result of commercial confidentiality. In addition, industrial processes commonly use environmentally hazardous materials such as cyanide compounds [42,43]. A few studies have been published on the electrochemical deposition of Au-Ag alloy films [44][45][46][47].…”

“…For example, in some AM-LPBF AlSi10Mg items, additional coatings may be needed to improve electrical and thermal conductivity or to achieve a certain aesthetic appearance. The shiny and luxurious appearance of gold [43], silver [42], and electrum [48] plating can be used in numerous applications, among them replicas of ancient objects, such as valuable coins for museum presentations [42,43]. ELD of gold [49] and silver [50] metals can also be applied over AM fused filament fabrication (AM-FFF) acrylonitrile butadiene styrene (ABS) polymer objects when an appropriate chemical pretreatment process of the surface is done [49,50].…”

“…The objective of this research is to study the use of a novel environmentally friendly ELD finishing process by gold, silver, and electrum, of AM-LPBF AlSi10Mg parts, as a part of their post-printing surface modification. In addition, based on previous work of Dresler et al 2019 [42] and Inberg et al 2020 [43,48], this review aims to propose a methodology for effective Au, Ag, and Au-Ag ELD coatings of AM-LPBF AlSi10Mg objects. We should point out that one of the highlights of the technologies described here is the surface activation method.…”

“…Scanning electron micrographs reveal that the powders show an irregular particles shape with a low quantity of elongated particles and only a limited satellite attachment on the powder surface (Figure 2a). The powder's microstructure (Figure 2b) consists of a primary α-Al matrix with cellular-dendritic and eutectic microstructures with very fine fibrous Si; some scattered micron size porosity is also evident [42]. The specimens (Figure 1d) were printed with a 400 W continuous Yb:YAG fiber laser beam (laser beam diameter ≈100 µm) along the vertical Z-axis (Figure 1c) with a scanning velocity of ≈1 m•s −1 .…”

“…An average layer thickness of ≈60 µm prior to melting led to a solid layer thickness of ≈30 µm after solidification. A post T5 heat treatment was performed on the as-built specimens, i.e., holding the disk-shape specimens for 2 h at 300 °C in an air-furnace followed by furnace cooling [42]. The specimens (Figure 1d) were printed with a 400 W continuous Yb:YAG fiber laser beam (laser beam diameter ≈100 µm) along the vertical Z-axis (Figure 1c) with a scanning velocity of ≈1 m•s −1 .…”