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Measurement of focal plane error in laser powder bed fusion machines
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Evolution of Y[subscript 2]O[subscript 3] dispersoids during laser powder bed fusion of oxide disper
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Residual stress analysis of in situ surface layer heating effects on laser powder bed fusion of 316L stainless steel
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Study of printability and porosity formation in laser powder bed fusion built hydride-dehydride (HDH
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Residual stresses and microstructure within Allvac 718Plus laser powder bed fusion bars
The residual stresses within Allvac 718Plus bars built using LBPF with different laser powers, speeds and table displacements were measured using diffraction and mechanical methods and modelled with the baseplate attached and then removed. The residual stress profiles within the bars from the top surface down through the bulk were all quite similar, becoming less tensile due to a strain hardening mechanism. Table displacement has the greatest impact on residual stress, decreasing with increasing displacement/powder layer thickness. There was good agreement amongst the modeling and measurements. The microstructures were examined and varied slightly with energy density with higher densities having larger grains and enhanced post solidification diffusion. We found energy density had minimal impact on the residuals stresses within the parameters to produce dense material.
Solute and phase heterogeneous distribution at different scales and its effect on ageing physical phenomena in a laser powder bed fusion produced maraging steel
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A mechanistic study on environment gas in laser powder bed fusion
A variety of protective or reactive environmental gases have recently gained growing attention in laser-based metal additive manufacturing (AM) technologies due to their unique thermophysical properties and the potential improvements they can bring to the build processes. However, much remains unclear regarding the effects of different gas environments on critical phenomena in laser AM, such as rapid cooling, energy coupling, and defect generation. Through simultaneous high-speed synchrotron x-ray imaging and thermal imaging, we identify distinct effects of two environmental gases in laser AM and gained a deeper understanding of the underlying mechanisms. Compared to the commonly used protective gas, argon, it is found that helium has a negligible effect on cooling the part. However, helium can suppress unstable keyholes by decreasing effective energy absorption, thus mitigating keyhole porosity generation and reducing pore size under certain processing conditions. In conclusion, these observations provide guidelines for the strategic use of environmental gases in laser AM to produce parts with improved quality.
Predictive microstructure distribution and printability maps in laser powder bed fusion for a Ni–Cu alloy
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Microstructure prediction for Ti-22Al-25Nb in laser powder bed fusion
This work presents a physics-informed framework for predicting solidification morphology and defect susceptibility in additively manufactured Ti–22Al–25Nb across a broad processing space. The framework integrates solidification microstructure selection (SMS) analysis with a single-track defect-based printability map to establish a unified methodology linking processing parameters to both interfacial morphology and manufacturability. Thermal gradients G and solidification rates R are first computed using the Thermo-Calc Additive Manufacturing (TC-AM) module, a finite-interface-dissipation (FID) phase-field (PF) model coupled with CALPHAD method is then employed to systematically distinguish planar and dendritic regimes as functions of $G$ and $R$. By superimposing the printability map onto the morphology projections, a comprehensive process–structure framework is obtained. Across most processing conditions, the predicted microstructure is predominantly dendritic, while planar growth emerges only under selected laser power $P$ and scan speed $v$ combinations. In addition to morphology classification, the framework quantifies the dendritic area fraction and introduces a width-based morphology descriptor to characterize the spatial extent of planar/dendritic regions within the melt pool. It provides mechanistic insight into the interplay between solidification physics and defect formation, offering practical guidance for parameter selection and microstructural control in Ti–22Al–25Nb additive manufacturing (AM).
Inter-melt pool corrosion and repassivation of SS316L stainless steel processed by laser powder bed fusion
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Resolution and geometric limitations in laser powder bed fusion additively manufactured GRCop-84 structures for a lower hybrid current drive launcher
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Near-threshold fatigue crack growth in laser powder bed fusion produced alloy 718
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Crack growth in laser powder bed fusion fabricated alloy 718 at 650 °C under static and cyclic loading
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