Table 1 Summarizing and comparison of... | Emerald Publishing

Table 1

Summarizing and comparison of current multimaterial additive manufacturing technologies

Techniques	Feeding material	Energy source	Resolution dependence	Geometrical deviation and distortion	Benefits and limitations	Ref
Material extrusion	Metal-filled Thermoplastic granulated feedstock, bars, and filaments	Heating elements to heat the extrusion nozzles to melt the binder, and sintering in the furnace	On nozzle diameter nozzle (diameters of 0.25–0.8 mm) and filler metal powder size	Deviation: Relatively high due to binder decomposition and powder particle rearrangement, and integration Distortion: Relatively low, such as curling and wrapping due to being high-power-source-free	Benefits: Relatively quick (printing speed of 5–80 mm/s), low cost, simple, no direct metal powder involved, a wide range of materials available, no high-power energy source Limitations: No developed systems for multimaterial metal parts yet, low resolutions, lower relative density, sintering required, difficult to apply for complex parts, binder pollution, poor surface quality	(Watschke et al., 2018; Putra et al., 2020; Suwanpreecha and Manonukul, 2022)
Sheet lamination	Metallic sheets	Laser	Minimum sheets/foils thickness	Very high	Benefits: Low cost, relatively quick, cheap feeding materials Limitations: Delamination, low density, low resolution, very limited geometrical designs, thermally-induced stresses, not well developed for metals yet	(Wimpenny, Bryden and Pashby, 2003; Guo et al., 2019; Salmi, 2021)
Liquid metal deposition	Wires of low temperature alloys (e.g. Aluminium)	Heating elements to melt the wire inside the crucible before deposition	On deposition nozzle	Relatively high	Benefits: Suitable for low temperature alloys like aluminium alloys, low-cost feeding materials, Limitations: Limited technological advancements, not yet developed for multimaterial purposes	(Sukhotskiy et al., 2017; Ruggles, 2018; Kapil et al., 2023)
Binder jetting	Metal powders of 25–53 μm, adhesives for binding	Sintering furnaces	On metal powder particle sizes and printhead resolution	Deviation: Relatively high deviation due to binder decomposition and powder particle rearrangement Distortion: Relatively lower distortions	Benefits: Relatively quick, clean, low-cost equipment, no support structures required in general, low distortion due to missing thermally induced stresses induced by high power energy sources, high relative densities (higher than 99%) Limitations: Sintering challenge for green multimaterial components (shrinkage and possible gravity-based distortion during sintering), requiring a multimaterial powder handling system similar to PBF, relatively weaker material properties than other high-power techniques, sintering dependent	(Chou et al., 2013; Hong et al., 2016; Bai and Williams, 2018; Mostafaei et al., 2018; Toursangsaraki, 2018; Ziaee and Crane, 2019; Li et al., 2020; Putra et al., 2020)
Directed energy deposition	Powder (between 20–30 μm and 200 μm), wire	Laser, electron beam, plasma arc	The energy source spot size (few tenths to hundreds of μm), feeding rate, powder size, nozzle diameter (minimum feature size of about 250 m, minimum reported layer thickness of about 200 μm)	Relatively high	Benefits: Relatively higher deposition rates, low oxidation, ideal for large scale fabrications and in situ repairing, good development for multimaterial printings, suitable for FGMs Limitations: Relatively large resolution/features, limited designs for smaller features such as for fine lattices, relatively large geometrical deviation and distortions, risk of inhomogeneity, and relatively lower densities than LPBF	(Gibson, Rosen and Stucker, 2015; Thompson et al., 2015; Bobbio et al., 2017; Woo et al., 2019; Ahn, 2021; Feenstra et al., 2021)
Powder bed fusion	Powder	Laser, electron beam	Laser or electron beam spot size, multimaterial powder deposition system limitations, powder size	Relatively high	Benefits: Suitable for complex geometries with fine features such as lattices, porous materials, topology-optimized complex designs, etc., relatively low geometrical deviation than Binder Jetting due to absence of a binder Cons: Relatively expensive and complex technology, Higher cooling rates than DED prone to distortions, hot cracks, distortions through thermally induced stresses, supporting required, challenging for overhangs, challenging for re-cyclability and reusability of the remaining powder	(Mussatto, 2022; Wang et al., 2022; Sahu et al., 2024)

Techniques	Feeding material	Energy source	Resolution dependence	Geometrical deviation and distortion	Benefits and limitations	Ref
Material extrusion	Metal-filled Thermoplastic granulated feedstock, bars, and filaments	Heating elements to heat the extrusion nozzles to melt the binder, and sintering in the furnace	On nozzle diameter nozzle (diameters of 0.25–0.8 mm) and filler metal powder size	Deviation: Relatively high due to binder decomposition and powder particle rearrangement, and integration Distortion: Relatively low, such as curling and wrapping due to being high-power-source-free	Benefits: Relatively quick (printing speed of 5–80 mm/s), low cost, simple, no direct metal powder involved, a wide range of materials available, no high-power energy source Limitations: No developed systems for multimaterial metal parts yet, low resolutions, lower relative density, sintering required, difficult to apply for complex parts, binder pollution, poor surface quality	(Watschke et al., 2018; Putra et al., 2020; Suwanpreecha and Manonukul, 2022)
Sheet lamination	Metallic sheets	Laser	Minimum sheets/foils thickness	Very high	Benefits: Low cost, relatively quick, cheap feeding materials Limitations: Delamination, low density, low resolution, very limited geometrical designs, thermally-induced stresses, not well developed for metals yet	(Wimpenny, Bryden and Pashby, 2003; Guo et al., 2019; Salmi, 2021)
Liquid metal deposition	Wires of low temperature alloys (e.g. Aluminium)	Heating elements to melt the wire inside the crucible before deposition	On deposition nozzle	Relatively high	Benefits: Suitable for low temperature alloys like aluminium alloys, low-cost feeding materials, Limitations: Limited technological advancements, not yet developed for multimaterial purposes	(Sukhotskiy et al., 2017; Ruggles, 2018; Kapil et al., 2023)
Binder jetting	Metal powders of 25–53 μm, adhesives for binding	Sintering furnaces	On metal powder particle sizes and printhead resolution	Deviation: Relatively high deviation due to binder decomposition and powder particle rearrangement Distortion: Relatively lower distortions	Benefits: Relatively quick, clean, low-cost equipment, no support structures required in general, low distortion due to missing thermally induced stresses induced by high power energy sources, high relative densities (higher than 99%) Limitations: Sintering challenge for green multimaterial components (shrinkage and possible gravity-based distortion during sintering), requiring a multimaterial powder handling system similar to PBF, relatively weaker material properties than other high-power techniques, sintering dependent	(Chou et al., 2013; Hong et al., 2016; Bai and Williams, 2018; Mostafaei et al., 2018; Toursangsaraki, 2018; Ziaee and Crane, 2019; Li et al., 2020; Putra et al., 2020)
Directed energy deposition	Powder (between 20–30 μm and 200 μm), wire	Laser, electron beam, plasma arc	The energy source spot size (few tenths to hundreds of μm), feeding rate, powder size, nozzle diameter (minimum feature size of about 250 m, minimum reported layer thickness of about 200 μm)	Relatively high	Benefits: Relatively higher deposition rates, low oxidation, ideal for large scale fabrications and in situ repairing, good development for multimaterial printings, suitable for FGMs Limitations: Relatively large resolution/features, limited designs for smaller features such as for fine lattices, relatively large geometrical deviation and distortions, risk of inhomogeneity, and relatively lower densities than LPBF	(Gibson, Rosen and Stucker, 2015; Thompson et al., 2015; Bobbio et al., 2017; Woo et al., 2019; Ahn, 2021; Feenstra et al., 2021)
Powder bed fusion	Powder	Laser, electron beam	Laser or electron beam spot size, multimaterial powder deposition system limitations, powder size	Relatively high	Benefits: Suitable for complex geometries with fine features such as lattices, porous materials, topology-optimized complex designs, etc., relatively low geometrical deviation than Binder Jetting due to absence of a binder Cons: Relatively expensive and complex technology, Higher cooling rates than DED prone to distortions, hot cracks, distortions through thermally induced stresses, supporting required, challenging for overhangs, challenging for re-cyclability and reusability of the remaining powder	(Mussatto, 2022; Wang et al., 2022; Sahu et al., 2024)

Source(s): Table by authors