Characterization of metal additive manufacturing surfaces using synchrotron X-ray CT and micromechanical modeling

Effects of Post-processing on the Surface Finish, Porosity, Residual Stresses, and Fatigue Performance of Additive Manufactured Metals: A Review

“…On a rough metal surface, stress concentrates at many locations on the surface that can serve as potential crack initiation sites (Ref 32 ). As shown in the schematic diagram in Fig.…”

“…It should also be noted that while the current surface characterization methods (both stylus and light-based profilometry) are able to capture the features of the outermost surface of the material, they are not capable of capturing the three-dimensional (3D) subsurface details. The subsurface features should not be ignored, as subsurface porosity could be detrimental to fatigue performance because they provide stress raisers (Ref 32 ). As demonstrated by Kahlin and co-workers (Ref 47 ), surface roughness alone is not a sufficient indicator of fatigue performance, as surface defects can be hidden below a smooth surface.…”

“…As demonstrated by Kahlin and co-workers (Ref 47 ), surface roughness alone is not a sufficient indicator of fatigue performance, as surface defects can be hidden below a smooth surface. Kantzo and co-workers (Ref 32 ) demonstrated that by capturing the full 3D surface and subsurface features through synchrotron-based x-ray computed tomography, better prediction of the mechanical properties of AM metals can be achieved.…”

High cycle fatigue behavior and life prediction for additively manufactured 17-4 PH stainless steel: Effect of sub-surface porosity and surface roughness

“…Three major approaches to consider the effects of net-shape surface condition are adopted in the literature: (i) the evaluation of the stress concentration induced by surface features [10,24,[26][27][28]; (ii) estimating a fictitious (i.e. equivalent initial flaw size approach) crack representing the 'as-built' condition [14,29], and (iii) measuring the dimensions of surface features for applying 'short crack' fracture mechanics concepts [10,14].…”

Combined effect of surface anomalies and volumetric defects on fatigue assessment of AlSi7Mg fabricated via laser powder bed fusion

“…Numerous reports have been published on the surface metrology of additive manufactured parts based on roughness evaluation using stylus profilometers [6,18,24,[30][31][32][33][34][35] and other non-contact methods such as confocal microscopy [36][37][38], focus variation microscopy [31], coherence scanning interferometry [39,40] and X-ray micro-computed tomography (µCT) [41][42][43][44][45][46][47]. However, a combined study of the surfaces of AM materials using metrological methods and cross-sectional analysis aimed at coupling the surface roughness parameters with the features of the AMZ has not yet been performed.…”