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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 631 records · Page 35
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Correlation Between Microstructure and In-Field Performance of Zr-Added REBCO Coated Conductors Made by Advanced MOCVD

In this paper, we present correlation features between critical current density (J c ) and microstructural characteristics of Zr-added (0, 5, and 15 mol.%) REBa 2 Cu 3 O 7-x (REBCO and RE = rare earth) coated conductors fabricated by the novel advanced metal organic chemical vapor deposition technique. The J c along the tape normal (~ B || c-axis) measured by a vibrating sample magnetometer at 30 and 65 K and magnetic flux density range of 0-14 T was used for qualitative comparison of different Zr-added REBCO tapes. It is found that tapes with enhanced in-field J c exhibit a rise of critical current (plateau or fishtail effect) at magnetic flux density 1-8 T and temperatures 65 K. The TEM microstructure analysis indicates that the plateau effect is not the intrinsic property of REBCO matrix but depends on size distribution and density of BaZrO 3 (BZO) self-assembled nanocolumns. Two types of BZO microstructures have been identified: one with uniform BZO diameter 4-7 nm, whereas some films exhibit bottle-shaped BZO nanocolumns with alternating wide and narrow sections, 7-13 and 4-6 nm, respectively. The non-uniform shape and broad size distribution of BZO nanocolumns are correlated to more vortex pinning strength and matching field.

2G high-temperature superconductor (2GHTS)↗
DOE OSTI2018

Parameters of a Microstructure of Erosion Regions during the Action of a Spark Discharge on a Copper Electrode Surface in Air

The parameters of a microstructure of regions of action of a spark discharge on a copper plane electrode surface in air at atmospheric pressure in the spike–plane gap both for positive and negative polarity of a spike have been studied using scanning electron microscopy. It has been found that regions of action have the appearance of rounded spots or groups of spots with an internal structure in the form of agglomeration of a large number of microcraters. It has been shown that the statistical distributions of microcrater diameters and intermicrocrater distances are characterized by several local maximums that determine the presence of several predominant values of these parameters in a spot. It has been revealed that the microstructure of a spot is characterized by the fractal behavior and the fractal dimensionalities of the microstructure have been determined.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2022

Parametric Study of the Influence of Support Type, Presence of Platinum on Support, and Ionomer Content on the Microstructure of Polymer Electrolyte Fuel Cell Catalyst Layers

We report Ultra-small angle X-ray scattering (USAXS) was employed to investigate the effects of carbon support type, the presence of platinum on carbon, and ionomer loading on the microstructure of polymer electrolyte fuel cell (PEFC) catalyst layers (CLs). Particle size distributions (PSDs), obtained from fitting the measured scattering data were used to interpret the size of carbon aggregates (40–300 nm) and agglomerates (>400 nm) from two-component carbon/ionomer and three-component platinum/carbon/ionomer CLs. Two types of carbon supports were investigated: high surface area carbon (HSC) and Vulcan XC-72. CLs with a range of perfluorosulfonic acid (PFSA) ionomer to carbon (I/C) ratios (0.2–1.2) and also with perfluoroimide acid (PFIA) ionomer were studied to evaluate the effect of ionomer on CL microstructure. The carbon type, the presence of platinum, and ionomer loading were all found to significantly impact carbon agglomeration. The extent of Pt/C agglomeration in the CL was found to increase with increasing ionomer and platinum concentration and to decrease with increasing carbon surface area. Platinum electrochemically-active surface area (ECSA) and local oxygen transport resistance (R nF ) were correlated to the CL microstructure to yield relationships affecting electrode performance.

25 ENERGY STORAGE↗
DOE OSTI2022

ExaAM: Metal additive manufacturing simulation at the fidelity of the microstructure

Additive manufacturing (AM), or 3D printing, of metals is transforming the fabrication of components, in part by dramatically expanding the design space, allowing optimization of shape and topology. However, although the physical processes involved in AM are similar to those of welding, a field with decades of experimental, modeling, simulation, and characterization experience, qualification of AM parts remains a challenge. The availability of exascale computational systems, particularly when combined with data-driven approaches such as machine learning, enables topology and shape optimization as well as accelerated qualification by providing process-aware, locally accurate microstructure and mechanical property models. We describe the physics components comprising the Exascale Additive Manufacturing simulation environment and report progress using highly resolved melt pool simulations to inform part-scale finite element thermomechanics simulations, drive microstructure evolution, and determine constitutive mechanical property relationships based on those microstructures using polycrystal plasticity. We report on implementation of these components for exascale computing architectures, as well as the multi-stage simulation workflow that provides a unique high-fidelity model of process–structure–property relationships for AM parts. In addition, we discuss verification and validation through collaboration with efforts such as AM-Bench, a set of benchmark test problems under development by a team led by the National Institute of Standards and Technology.

3D printing↗
DOE OSTI2024

Microstructure development during rapid alloy solidification

Abstract Solidification processing of structural alloys can take place over an extremely wide range of solid–liquid interface velocities spanning six orders of magnitude, from the low-velocity constitutional supercooling limit of microns/s to the high-velocity absolute stability limit of m/s. In between these two limits, the solid–liquid interface is morphologically unstable and typically forms cellular-dendritic microstructures, but also other microstructures that remain elusive. Rapid developments in additive manufacturing have renewed the interest in modeling the high-velocity range, where approximate analytical theories provide limited predictions. In this article, we discuss recent advances in phase-field modeling of rapid solidification of metallic alloys, including a brief description of state-of-the-art experiments used for model validation. We describe how phase-field models can cope with the dual challenge of carrying out simulations on experimentally relevant length- and time scales and incorporating nonequilibrium effects at the solid–liquid interface that become dominant at rapid rates. We present selected results, illustrating how phase-field simulations have yielded unprecedented insights into high-velocity interface dynamics, shedding new light on both the absolute stability limit and the formation of banded microstructures that are a hallmark of rapid alloy solidification near this limit. We also discuss state-of-the-art experiments used to validate those insights. Graphical abstract

36 MATERIALS SCIENCE↗
DOE OSTI2019

Effect of α/β Forging on Microstructure and Texture Inhomogeneity in a Ti-1023 Forged Disk

The microstructure and texture distribution of a Ti-1023 forged disk were investigated by scanning electron microscopy and synchrotron-based high-energy X-ray diffraction. The finite element method was used to simulate temperature and strain distribution in order to investigate the relationship of the α/β forging process with microstructure and texture distribution. A bimodal microstructure and rolling textures with large inhomogeneity were observed in the disk. A plate-like and a necklace-like morphology and volume fraction variations of the primary α phase were observed in different regions with different forging conditions, such as temperature, deformation, position, and high density of flow lines. Texture sharpness distribution of the β phase was in good agreement with the strain distribution, which suggests deformation may play the most important part in the texture inhomogeneity. A weak cube texture was obtained near the center of the disk, and fiber textures were found near the rim of the disk. The primary a phase also exhibited a transverse texture, which is favored by large deformation.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Microstructure Experiments-Enabled MARMOT Simulations of SiC/SiC-based Accident Tolerant Nuclear Fuel System

We have undertaken an experimental-computational project that addresses a few key technology gaps associated with the use of SiC/SiC composites for light water reactor fuel cladding. Two principal endeavors in this project are to assess the irradiation-induced microstructural changes and swelling in SiC/SiC composites, and to characterize and model the porous oxide surface layer (when exposed to steam) along SiC recession that is detrimental to the clad integrity under accident conditions. The project tasks are: (i) ion irradiation and characterization (University of Tennessee, Knoxville), (ii) mechanical tests and analysis (University of South Carolina), (iii) steam exposure tests (Oak Ridge National Laboratory), (iv) electron microscopy and spectroscopic characterization (NC State University), (v) x-ray microscopy and reconstruction (University of South Carolina and NC State University), (vi) phase field modeling and simulations (NC State University and Idaho National Laboratory). The effects of 10 MeV Au ion irradiation at 350°C on the microstructure evolution in SiC/SiC composites are investigated at doses up to 400 displacements per atom (dpa) at the University of Tennessee, Knoxville. Atomic force microscopy and optical profilometry reveal irradiation induced axial and radial shrinkage of the fibers for doses greater than 10 dpa. Based on detailed electron microscopy characterization, the primary cause of the fiber shrinkage is attributed to irradiation-induced loss of carbon packets. Additionally, the multilayer PyC interface is observed to portray high resistance to irradiation damage. The mechanical response and failure mechanisms of un-irradiated samples is also assessed through loading tests and X-ray imaging at the University of South Carolina. Steam exposure tests are performed at the Oak Ridge National Laboratory in a facility that represents a reactor pressure vessel under a loss-of-coolant-accident scenario. The samples that are analyzed methodically in this report are tested for 32/31 hours at 1200°C with a velocity of 0.25 cm/s for the pressures: 0.1 MPa, 0.45 MPa, 0.92 MPa and 1.38 MPa. Scanning/transmission electron microscopy analysis conducted at the NC State University (NCSU) shows that the oxide layer thickness increases with the steam pressure. While the oxide layer is crystalline (α- cristobalite) for the pressures 0.45 MPa, 0.92 MPa and 1.38 MPa, the layer is amorphous at 0.1 MPa. Results from Raman spectroscopy have also confirmed the formation of α-cristobalite phase of SiO₂. The abrupt increase in the integrated Raman intensity ratio between steam pressures 0.1 and 0.45 MPa suggests the onset of accelerated crystallization. Non-destructive three dimensional X-ray microscopy/tomography (XCT) and computational image processing techniques are employed by the University of South Carolina to probe the porous oxidation features on SiC samples at varying pressures. Interestingly, most pores are observed to be located away from the surface as well as the oxide-SiC interface. The average oxide layer thickness assessed from the XCT analysis is seen to be in excellent agreement with the values determined through scanning electron microscopy analysis for the highest pressures where the oxide layer is relatively more uniform. A phase-field model developed by the NC State University and Idaho National Laboratory for simulating oxidation of SiC by steam captures the paralinear kinetics of SiC oxidation with a high degree of fidelity. Results from quasi-one-dimensional and two dimensional simulations show that the pores with oxidizing species lead to a higher volatilization rate. These simulations indicate that the enhanced apparent volatilization rates at higher pressures observed in experiments can be rationalized by the increased volatilization from the pores. The project team has also successfully developed the capability to import images from experiments for realistic evolution of the oxidizing microstructure.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2022

Microstructural Characterization of As-Cast MP-1 Experiment U-10Mo Alloy

The Mini-Plate-1 (MP-1) test is the first in a series of fuel testing campaigns with the purpose of achieving regulatory qualification for the U-10Mo monolithic plate-type fuel system. The objective of MP-1 is to assess fuel performance behavior of fuel plates fabricated by a commercial fuel fabricator (BWX Technologies, Inc.) and make sure that the fuel maintains mechanical integrity and geometric stability and behaves in a stable and predictable manner. As a part of MP1 fabrication campaign several castings were prepared. The castings were vacuum induction melted using HEU pieces mixed with a master alloy made up of DU and molybdenum pieces. The Master Alloy was poured by a commercial vendor. There was little mixing during melting. A three-plate mold was utilized to form three U-10Mo plates per melt pour. The work described here shows that the resulting microstructure varies greatly from one cast plate to another, and from the top to the bottom of each cast plate. The extent of variation in microstructural features such as grain size, second phase particle (SPP) distribution and morphology, microsegregation of constituents within the dendritic microstructure, porosity, and casting abnormalities are presented and discussed.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2019

Correlation of Microstructure and Mechanical Properties of Metal Big Area Additive Manufacturing

Metal Big Area Additive Manufacturing (MBAAM) is a novel wire-arc additive manufacturing method that uses a correction-based approach developed at the Oak Ridge National Laboratory (ORNL). This approach is an integrated software method that minimizes the dynamic nature of welding and compensates for build height. The MBAAM process is used to fabricate simple geometry thin walled specimens, using a C-Mn steel weld wire, to investigate the scatter in mechanical properties and correlate them to the underlying microstructure. The uni-axial tensile tests show isotropic tensile and yield properties with respect to building directions, although some scatter in elongation is observed. Large scatter is observed in the Charpy Impact tests. The microstructure characterization reveals mostly homogenous ferrite grains with some pearlite, except for some changes in morphology and grain size at the interface between the build and the base plate. The measured properties and microstructure are compared with the toughness and strength values reported in the literature, and a hypothesis is developed to rationalize the differences. Overall, the MBAAM process creates stable, isotropic, and weld-like mechanical properties in the deposit, while achieving a precise geometry obtained through a real-time feedback sensing, closed loop control system.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Microcomputed X-Ray Tomographic Imaging and Image Processing for Microstructural Characterization of Explosives

Microstructural characterization of composite high explosives (HEs) has become increasingly important over the last several decades in association with the development of high fidelity mesoscale modeling and an improved understanding of ignition and detonation processes. HE microstructure influences not only typical material properties (e.g., thermal, mechanical) but also reactive behavior (e.g., shock sensitivity, detonation wave shape). A detailed nondestructive 3D examination of the microstructure has generally been limited to custom-engineered samples or surrogates due to poor contrast between the composite constituents. Highly loaded (>90 wt%) HE composites such as plastic-bonded explosives (PBX) are especially difficult. Here, we present efforts to improve measurement quality by using single and dual-energy microcomputed X-ray tomography and state-of-the-art image processing techniques to study a broad set of HE materials. Some materials, such as PBX 9502, exhibit suitable contrast and resolution for an automatic segmentation of the HE from the polymer binder and the voids. Other composite HEs had varying levels of success in segmentation. Post-processing techniques that used commercially available algorithms to improve the segmentation quality of PBX 9501 as well as zero-density defects such as cracks and voids could be easily segmented for all samples. Aspects of the materials that lend themselves well to this type of measurement are discussed.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Effect of Initial Microstructure on the Toughness of Coarse-Grained Heat-Affected Zone in a Microalloyed Steel

Toughness of the coarse-grained-heat-affected-zone (CGHAZ) strongly depends on the prior austenite grain size. The prior austenite grain size is affected not only by chemical composition, thermal cycle, and dissolution of second-phase particles, but also by the initial microstructure. The effect of base metal microstructure (ferrite/pearlite obtained by air cooling and martensite obtained by water-quenching) on Charpy impact toughness of the CGHAZ has been investigated for different heat inputs for high-heat input welding of a microalloyed steel. A welding thermal cycle with a heat input of 100 kJ/cm and 400 kJ/cm were simulated on the MMS-300 system. Despite a similar microstructure in the CGHAZ of both the base metals, the average Charpy impact energy for the air-cooled base metal was found to be higher than the water-quenched base metal. Through thermo-kinetic simulations, it was found that a higher enrichment of Mn/C at the ferrite/austenite transformation interface of the CGHAZ of water-quenched base metal resulted in stabilizing austenite at a lower A1 temperature, which resulted in a coarser austenite grain size and eventually lowering the toughness of the CGHAZ.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Investigation of Microstructures and Tensile Properties of 316L Stainless Steel Fabricated via Laser Powder Bed Fusion

In this study, a thorough investigation of the microstructures and tensile properties of 316L stainless steel fabricated via laser powder bed fusion (L-PBF) was done. 316L stainless steel specimens with two different thicknesses of 1.5 mm and 4.0 mm fabricated under similar conditions were utilized. Microstructural characterization was performed using optical microscopy (OM) and scanning electron microscopy (SEM) equipped with electron backscatter diffraction (EBSD). Melt pools and cellular structures were observed using OM, whereas EBSD was utilized to obtain the grain size, grain boundary characteristics, and crystallographic texture. The 1.5 mm thick sample demonstrated a yield strength (YS) of 538.42 MPa, ultimate tensile strength (UTS) of 606.47 MPa, and elongation to failure of 69.88%, whereas the 4.0 mm thick sample had a YS of 551.21 MPa, UTS of 619.58 MPa, and elongation to failure of 73.66%. These results demonstrated a slight decrease in mechanical properties with decreasing thickness, with a 2.4% reduction in YS, 2.1% reduction in UTS, and 5.8% reduction in elongation to failure. In addition to other microstructural features, the cellular structures were observed to be the major contributors to the high mechanical properties. Using the inverse pole figure (IPF) maps, both thicknesses depicted a crystallographic texture of {001} <101> in their as-built state. However, when subjected to tensile loads, texture transitions to {111} <001> and {111} <011> were observed for the 1.5 mm and 4.0 mm samples, respectively. Additionally, EBSD analysis revealed the pre-existence of high-density dislocation networks and a high fraction of low-angle grain boundaries. Interestingly, twinning was observed, suggesting that the plastic deformation occurred through dislocation gliding and deformation twinning.

316L stainless steel↗
NASA NTRS2018

Impact of Powder Variability on the Microstructure and Mechanical Behavior of Selective Laser Melted Alloy 718

Powder-bed additive manufacturing processes use fine powders to build parts layer-by-layer. Alloy 718 powder feedstocks for selective laser melting (SLM) additive manufacturing are produced commercially by both gas and rotary atomization and are available typically in the 10-45 or 15-45 microns size ranges. A comprehensive investigation was conducted to understand the impact of powder variability on the microstructure and mechanical behavior of SLM 718 heat treated to Aerospace Material Specification (AMS) 5664. This study included sixteen virgin powders and three once-recycled powders within the 10-45 and 15-45 microns size ranges that were obtained from seven direct source suppliers and one reseller. Although alike as highly regular spheroids, these powders showed distinct differences in composition (especially Al, C and N contents), particle size distributions, and powder features such as degree of agglomeration, fusion and surface roughness. Compositional differences expectedly had the strongest impact on microstructure. High N and C contents formed TiN-nitrides and/or (Nb,Ti,Mo)-C carbides on the grain boundaries, prevented recrystallization during heat treatment, and resulted in retained (001)-scalloped shaped grains that ranged from 19 to 41 microns in average size. In the absence of this particle pinning, the average grain size of the heat treated SLM 718 ranged from 51 microns to 90 microns. Room temperature tensile and high cycle fatigue (HCF) testing compared as-fabricated (AF) and low stress ground (LSG) surface conditions. Tensile testing revealed consistent behavior between the two surface conditions and amongst the powder lots. The finer grained SLM 718 builds displayed the lowest tensile properties. A SLM 718 build fabricated from a powder with eight times lower C content showed statistically better tensile properties presumably due to enhanced coarsening of (delta)-Ni3Nb precipitates. The specimens from once-recycled powders had slightly higher tensile strengths and slightly higher ductility compared to their virgin equivalents; once-recycling also did not substantially degrade the mean HCF life. The LSG fatigue lives agreed with conventionally manufactured 718 data, while AF lives exhibited a knock-down due to surface roughness. The fatigue lives of AF specimens were statistically equivalent across powder lots except for one and failures typically initiated at stress concentrators associated with SLM surface asperities. Fatigue testing of low stress ground specimens result in both transgranular and within facet crack initiations. More than half of the cracks initiated from these facets for the machined condition; however, these facets appeared to be within grains that were larger-than-average in size. A nitrogen-atomized powder with fine prior particles of TiN-nitrides and M(Ti,Nb,Mo)C carbides from atomization on powder surfaces resulted in the best fatigue performance with segregation of these particles to the SLM 718 grain boundaries leading to higher resistance to early-stage crack propagation. Typically the fine-grained builds with minor phases along the grain boundaries did not perform well in fatigue, whereas a larger-grain build with lower carbon content and coarser delta-Ni3Nb precipitates showed the next best HCF response. Further details of the build microstructure and its impact on tensile and fatigue behavior was considered.

laser deposition↗
NASA NTRSDate not supplied

Microstructural Characterization of Laser Powder Bed Fusion (L-PBF) Additively Manufactured Inconel 718 for Aerospace Application

Alloy 718 (Inconel 718) is used for aerospace applications because of its excellent corrosion resistance and mechanical properties. This alloy is particularly applicable in manufacturing components subjected to high temperatures in rocket engines, aero-engines, and gas turbines. Properties for this alloy when processing on systems from similar and different Laser Powder Bed Fusion (L-PBF) machines provide subtle differences due to process parameters, feedstock, and machine configurations. A series of sixteen L-PBF AM Inconel 718 geometric feature build plates have been evaluated for microstructure using optical microscopy. This study presents the details of the microstructure analysis concerning geometry and different machine platforms. Microstructural investigations of these samples included average grain width measurement for all the X-Y and Y-Z build layers and are accompanied by process parameters and powder characterization. The present work concludes with a discussion on the importance of captured differences among builds to understand the practical limitations among AM platforms.

Additive Manufacturing↗
NASA NTRSDate not supplied

Effect of Heat Treatment on the Microstructure and Mechanical Properties of Monel K500 Alloy Fabricated Via L-PBF and LP-DED

This study examines and compares the effect of different heat treatments (HT) on the microstructure and mechanical properties of Monel K500 fabricated using laser powder bed fusion (L-PBF) and laser powder directed energy deposition (LP-DED) technologies. The as-fabricated Monel K500 specimens exhibited dendritic microstructure and elemental micro-segregation due to high cooling rates induced during the fabrication process. The applicability of HT proposed in the literature for wrought Monel K500 was investigated for L-PBF and LP-DED using four different HT procedures involving hot isostatic pressing (HIP), solution annealing (SA), and aging. The mechanical properties of test specimens were evaluated using uniaxial tensile testing at room temperature. The microstructural evolution of test specimens during HT was analyzed using a scanning electron microscope. For all HT conditions investigated, L-PBF Monel K500 specimens consistently displayed higher strength and lower ductility compared to the LP-DED counterparts. The HT procedure involving HIP at 1160°C for 3hr at 100 MPa, SA at 1100°C for 15 min, and three step aging at 610°C for 16 hr, 540°C for 6 hr, and 480°C for 8 hr resulted in highest strength for both L-PBF and LP-DED fabricated Monel K500.

Additive manufacturing↗
DOE OSTI2025

SOC Microstructural Analyzer

This program was designed to analyze the 3-phase microstructure of the electrodes of a solid oxide fuel cell (SOFC) or electrolysis cell (SOEC), both referred to in combination as a solid oxide cell (SOC). It is agnostic to the exact system, so it could be repurposed to analyze any 3-phase microstructure. This tool directly analyzes segmented voxel-based data that has been segmented into phase IDs (1,2,3). The voxels will be analyzed directly for: - tortuosity factors - triple phase boundaries - 2-phase interfacial areas, using a meshed isosurface - mean diameters of each phase, using an inscribed sphere method - standard deviation of the diameters of each phase, from the same inscribed sphere data - connectivity information Comprehensive information is available in the readme file (within the zipped repository in Markdown language, and also available here as a rendered PDF). Please cite this page / DOI, as well as https://doi.org/10.1111/jace.14775, for usage.

3D microstructure↗
DOE OSTI2024

Tuning Microstructure of Mesophase Pitch Carbon Fiber by Altering the Carbonization Ramp Rate

The microstructure of mesophase pitch carbon fibers (CFs) are tuned by varying ramp rates from 1 to 50 °C min –1 up to 1000 °C to study the effect of ramp rate on CFs’ microstructure, thermal and mechanical properties with the goal of offsetting the cost by decreasing cycle time. The ramp rates represent carbonization times ranging from 16.4 to 1.17 h, not including cool down. Differential scanning calorimetry, thermogravimetric analysis, and derivative thermogravimetry are used to investigate the impact ramp rate has on the thermal properties of mesophase pitch. It is found that lower ramp rates are endothermic in nature with a lower temperature onset and maximum weight loss. Higher ramp rates possess an exothermic nature with higher temperatures resulting in maximal weight loss over a smaller range of temperatures. Mechanical testing shows varying CF strengths and moduli dependent on ramp rate and an optimized process is developed to produce the strongest CF. Furthermore, microstructural characterization revealed that faster ramp rates lead to smaller interplanar spacings and larger crystallites but possessed greater disorder.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Optimization of Processing, Microstructure, and Hardness of an Al–Ce–Ni–Mn–Zr Alloy With Laser Additive Manufacturing

Here, this study examines the processing behavior, microstructure, surface roughness, and hardness properties of an aluminum alloy containing 8.2 Ce, 4.5 Ni, 0.5 Mn, and 0.7 Zr (wt%) fabricated using laser powder bed fusion. Sixty samples were produced across a range of laser powers, scan speeds, and hatch spacings to evaluate their effect on porosity, hardness, and microstructural features. Porosity was measured using X-ray computed tomography, while microstructure and surface roughness were characterized by scanning electron (SEM) and laser confocal microscopy. High dense and cracking-free Al–Ni–Ce alloy was successfully manufactured. Porosity showed a U-shaped dependence on energy input, increasing under both insufficient and excessive melting conditions. Hardness increased with cooling rate due to finer cellular structures and solute redistribution. A general statistical model was developed to capture the relationships between processing parameters and material response. Results identify a narrow processing window defined by laser powers between 350 and 370 W, scan speeds from 1400 to 1800 mm/s, and hatch distances between 0.14 and 0.18 mm. Within this window, porosity is minimized (below 0.01%) and hardness is maximized (up to 160 HV), demonstrating that careful control of these parameters enables dense, high strength aluminum components suitable for demanding structural applications.

Aluminum alloys↗