A review of the process physics and material screening methods for polymer powder bed fusion additive manufacturing. (June 2019)

• Record Type: Journal Article
• Authors: Chatham, Camden A.; Long, Timothy E.; Williams, Christopher B.
• Is Part Of: Progress in polymer science. Volume 93(2019)
• Page Start: 68
• Page End: 95
• Publication Date: 2019-06
• Subjects: EA activation energy for degradation -- AM additive manufacturing -- vs, VB beam speed -- Tb bed temperature -- Tc crystallization temperature -- Q density -- DSC differential scanning calorimetry -- ED energy density -- EMR energy Melt Ratio -- EMRdeg energy melt ratio for degradation -- Hf enthalpy of melting -- Tm° equilibrium melting temperature -- μe extensional viscosity -- FEA filament extrusion atomization -- FTIRSpectroscopy Fourier Transform-Infrared Spectroscopy -- FFF fused filament fabrication -- Tg glass-transition temperature -- G gram -- hs, S hatch spacing -- HSS high-speed Sintering -- h hour -- IM injection molding -- J joules -- dL laser diameter -- PL laser power -- z layer thickness -- MFI melt flow index -- MFR melt flow rate -- Tm melting temperature -- m meter -- μm microns -- mm milimeter -- min minute -- d molar density -- MW molecular weight -- MJF multi-jet Fusion -- Nm nanometers -- x neck radius -- Td, 1% one-percent degradation -- TDegOnset onset of degradation -- r original particle radius -- Φ packing density -- P parachor -- Pa pascals -- ABS poly(acrylonitrile-co-butadiene-co-styrene) -- PAEK poly(aryl ether ketone) -- PBT poly(butylene terephthalate) -- PEEK poly(ether ether ketone) -- PEK poly(ether ketone) -- PEG poly(ethylene glycol) -- PPS poly(phenylene sulfide) -- PVA poly(vinyl alcohol) -- PA12, nylon 12 polyamide 12 -- PC polycarbonate -- PE polyethylene -- PP polypropylene -- PS polystyrene -- PBF Powder Bed Fusion -- RAM radiation absorbing material -- RPA revolution powder analyzer -- s second -- LBM selective laser beam melting -- SLS selective laser sintering -- G' shear storage modulus -- cp specific heat -- SSR stable sintering region -- epsilon dot strain rate -- γ, σ surface tension -- TGA thermogravimetric analysis -- TPE thermoplastic elastomers -- TPU thermoplastic polyurethane -- t, ϴ time -- UHMWPE ultra-high molecular weight polyethylene -- Mw weight average molecular weight -- η0 zero-shear viscosity; Powder bed fusion -- Selective laser sintering -- Polymer additive manufacturing -- Process parameter selection; Polymers -- Periodicals; Polymerization -- Periodicals; Polymers -- Industrial applications -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.progpolymsci.2019.03.003
• Languages: English
• ISSNs: 0079-6700

Abstract

Graphical abstract: Abstract: Powder bed fusion (PBF) is one of seven different classes of additive manufacturing (AM) technologies identified by ASTM and ISO. In polymer PBF, an infra-red energy source selectively fuses powder particles layer-by-layer into a three-dimensional structure. This enables the production of parts without the use of a mold, which is useful for prototyping and low-volume production. The early research in polymer PBF has focused largely on exploring the expanded design space afforded by the technology and modeling the heat transfer during fabrication. These are aspects that emphasize the manufacturing process and resultant quality in a material agnostic manner. Early investigations into structure-process-property relationships focused on the industrially dominant polyamide family. Only recently has research been conducted towards expanding the PBF material portfolio beyond nylon-12 and its composites. Guiding this research is the knowledge gained from studying the behavior of polyamides in PBF, which resulted in pervasive guidelines for material screening and process parameter development in polymer PBF, including the concepts of a "stable sintering region" and utilizing the "energy melt ratio" to set machine parameters. However, these guidelines are largely empirical and disproportionately focus on process parameter effects on the mechanical properties of the printed parts, instead of the intrinsic polymer properties and first principles of polymer science and engineering. This review categorically compiles the PBF AM literature by the three process sub-functions: powder recoating, energy input, and coalescence and cooling. The literature outlining the governing physics, structure-property-processing relationships enabling printing, and the process-structure-property relationships enabling targeted final part properties are discussed within each sub-function. Establishing these polymer-manufacturing relationships, both for printability and for final part property prediction, is important to aid in the identification and adaptation of existing polymers, and development of novel polymers, for PBF AM.