Improving the efficiency of advanced ultra-supercritical power plants requires hotside materials that maintain mechanical propertiesMechanical properties in high pressure and high temperature environments. Nickel superalloysNickel superalloy are a viable yet expensive option, but weldingWelding challenges can lead to premature joint failures. The goal of this work was to experimentally evaluate nickel superalloysNickel superalloy computationally designed to lower alloy cost and for improved weldabilityWeldability while maintaining mechanical propertiesMechanical properties. Two optimized nickel alloys were designed to these targets and compared to benchmark nickel superalloysNickel superalloy (Nimonic 263, Waspaloy, and/or 740H). Both optimized alloys (5Co-4Ti, 7Co-3Ti) had lower cost than benchmark superalloysSuperalloy. The 7Co-3Ti alloy had similar elastic modulus and room temperature hardnessHardness to the benchmark alloys, while the 5Co-4Ti alloy exceeded room temperature hardnessHardness and elastic modulus values. Solidification crackingSolidification cracking and strain-age cracking were assessed, and 7Co-3Ti had increased strain age and solidification crackingSolidification cracking resistance compared to commercial alloys.
A novel testing approach for cyclic crack-growthcyclic crack-growth characterization is presented, enabling faster data generation and evaluation of crack propagation behavior at both room and elevated temperatures. This is particularly relevant for superalloysSuperalloy used in critical high-temperature applications such as turbine engines, where fatigue cracks can lead to catastrophic failure. Due to their complex microstructuresMicrostructures, superalloysSuperalloy are especially sensitive to crack initiation and propagation, requiring accurate and efficient fatigue life prediction. Conventional fatigue crack-growth tests using compact tension or corner crack specimens under constant load amplitude are often time-consuming. However, particularly during alloy development and optimization, when rapid screening of material properties is necessary, faster methods would be useful. The new method presented here employs single-edge notched bend specimens following ASTM E1820, with cyclic loading, unloading, and reloading at a constant stress rate. The maximum stress increases incrementally with each cycle until fracture. At each maximum loading reversal point, the differential elastic modulus ( E_D ) is determined. Progressive crack growth reduces the load-bearing cross section and further decreases E_D . The stress dependence of the stiffness in the undamaged state E_D0 must be considered. The E_D/E_D0 ratio allows estimation of crack length and cross-sectional area reduction over time. For validation of this new approach, Alloy 718Alloy 718 was tested, stress-intensity factors were calculated according to ASTM E1820, and cyclic crack-growthcyclic crack-growth rates ( da/dN ) were plotted against the stress-intensity range ( Δ K_I ), producing classic fatigue crack-growth curves. The very good agreement with literature data demonstrates the strong potential of this method for accelerated material screening.
The influence of forgingForging conditions on grain growthGrain growth behavior during heat treatmentHeat treatment of Ni-based alloys for turbine disksTurbine disk was investigated. It was found that grain growthGrain growth behavior during super-solvus heat treatmentHeat treatment after forgingForging is affected by the following parameters, which are determined by the forgingForging conditions: -Grain growthGrain growth driving force (strain energy) and its balance with neighboring grains, -initial grain size distribution. ForgingForging temperature determined the average grain size after forgingForging, and the strain distribution determined the grain size distribution after solution treatmentSolution treatment. Even when the average grain size before heat treatmentHeat treatment was different, the final average grain size after solution treatmentSolution treatment was nearly constant as long as the strain distribution after forgingForging was uniform. This is considered to be because the driving forces for grain growthGrain growth became balanced among neighboring grains. To achieve the required properties for turbine disksTurbine disk, it is necessary to control the grain size after heat treatmentHeat treatment to an appropriate value. This study revealed that not only the heat treatmentHeat treatment conditions, but also the microstructureMicrostructure (grain size distribution) after forgingForging must be properly controlled. In addition to conventional process design methods based on preventing cracking and ensuring formability, a process selection method that considers grain growthGrain growth behavior after heat treatmentHeat treatment was proposed.
The manufacturing of gamma primeGamma prime (γ′) strengthening nickel-based superalloysSuperalloy using additive manufacturingAdditive manufacturing (AM) processes has received significant attention from both the industrial and research communities due to its outstanding high-temperatureHigh-temperature properties. Nevertheless, high crack susceptibilityCrack susceptibility remains a considerable challenge for superalloysSuperalloy with high γ′ volume fractions manufactured by the laser powder bed fusionLaser Powder Bed Fusion (PBF-LB) (PBF-LB) process. Post-heat treatmentHeat treatment (PHT) plays a key role in shaping γ′ morphology and minimizing crystallographic anisotropy to achieve the desired mechanical propertiesMechanical properties. However, studies focusing on microstructural and γ′ morphology changes in the sub-solvus PHT for PBF-LB-manufactured Alloy 247Alloy 247 are limited. This study investigates the effects of exposure to sub-solvus temperatures, ranging from 600 to 900 °C, with varying holding times of 30 to 180 min, on microstructural changes, γ′ morphology, crystallographic textureTexture, and hardnessHardness. The microstructural changes were analyzed using optical microscopy, scanning electron microscopy (SEM), and electron backscatter diffraction (EBSDElectron Backscatter Diffraction (EBSD)). The results show that the as-manufactured 247 alloy exhibits a fine cellular dendritic structure with a strong <001> columnar textureTexture, which is parallel to the build direction, achieving a hardnessHardness of 463 HV1.0. Exposure to 800 °C resulted in cuboidal γ′ precipitates, resulting in the highest hardnessHardness of 545 HV1.0. The EBSDElectron Backscatter Diffraction (EBSD) results confirmed a gradual decrease in low-angle grain boundaries. These results contribute to a deeper understanding of the kinetics ofΓ′ precipitation γ′ precipitationPrecipitation and identify the temperature ranges in which nucleation and growth of γ′ occur at an accelerated rate.
Understanding the microstructural evolutionMicrostructural evolution of Ni-base superalloysSuperalloy during cooling from solution heat treatmentHeat treatment is essential for optimizing turbine disc performance. In this study, a multi-technique approach was employed to investigate theγ′ precipitation γ′ precipitationPrecipitation behavior of Udimet 720LIUdimet 720LI under controlled continuous coolingContinuous cooling conditions. A series of cooling experiments were conducted using a quenching dilatometer to apply precisely defined cooling rates between 0.7 and 100 °C/s. Selected experiments were complemented by synchrotron-based small-angle X-ray scattering (SAXSSmall-Angle X-ray Scattering (SAXS)) measurements to track the precipitation kineticsPrecipitation kinetics during cooling. Post-cooling microstructural characterization by scanning electron microscopy (SEM) showed that the grain size and primary γ′ precipitates remained unaffected by the cooling rate, whereas the secondary γ′ precipitates exhibited a strong cooling rate sensitivityCooling rate sensitivity. Their average diameter followed a power-law relationship with cooling rate, with an exponent consistent with diffusion-controlled growth. The size distributions were broad at slow cooling and narrow at high cooling rates, in agreement with the nucleation burst theory described in literature. The SAXSSmall-Angle X-ray Scattering (SAXS) analysis showed very good agreement with the SEM results and additionally revealed the presence of fine tertiary γ′ precipitates, with diameters below the SEM resolution limit. These findings highlight the importance of combining SEM with in-situ SAXSSmall-Angle X-ray Scattering (SAXS) to capture the full precipitate population across multiple size scales. By linking in-situ phase transformation kinetics with post-cooling microstructural analysis, this study establishes a framework for quantifying the relationship between cooling rate and γ′ evolution and supports the development of optimized heat treatmentHeat treatment strategies for turbine disc alloys.
HeteroepitaxialRecrystallization recrystallizationHeteroepitaxial recrystallization (HeRX), the nucleationHeteroepitaxial recrystallization of coherent γ grains at primary γ ' particles, has many potentialRecrystallization avenues for microstructureMicrostructure control in Ni-base superalloysSuperalloy. HeRX phenomena have been studied onlyTemperature gradient under hot deformationDeformation near the solvus temperature, limiting ourTemperature gradient understanding of its impact on final microstructureMicrostructure under inhomogeneousHeteroepitaxial recrystallization strain and temperature conditions during processingProcessing and in-service. In this study, steep gradients of strain and temperature were induced to elucidate their effects on the frequency and growth of HeRX grains in a polycrystalline Ni-base superalloySuperalloy, ATI 720. More frequent HeRX formation and reduced annealing twinTwin density were observed at intermediate temperatures as compared to near-solvus temperatures. The findings suggest that the role of primary γ ' particles can vary, either as a source of HeRX nucleation or annealing twinTwin nucleation, depending on the annealing temperature. This suggests that more precise grain structureGrain structure control for improved fatigue life can be achieved using the HeRX phenomena.
Nickel-based superalloysSuperalloy are essential for high-temperatureHigh-temperature applications due to their exceptional mechanical propertiesMechanical properties, largely attributed to the precipitationPrecipitation of the ordered γ′ phase. Whileγ′ precipitation γ′ precipitationPrecipitation is typically thermally activated, dislocations introduced during deformationDeformation can act as preferential nucleation sites, influencing kinetics and morphology. This study examines the effect of hot deformationDeformation on γ′ precipitationγ′ precipitation in nickel-based superalloySuperalloy VDM AlloyAlloy 780 780. Samples were solution-treated for 15 min to remove pre-existing precipitates, cooled to subsolvus temperature, and deformed under controlled strain rate and up to a high strain level before quenching. MicrostructuresMicrostructures were compared to undeformed references subjected to the same thermal path. Under the investigated thermomechanical conditions, no precipitationPrecipitation occurred during deformationDeformation, indicating insufficient time for nucleation. Post-deformationDeformation holding promoted precipitationPrecipitation in two domains: non-recrystallized grains with high dislocation density and recrystallized grains free of stored energy. In non-recrystallized grains, precipitationPrecipitation was rapid, reaching equilibrium within five minutes and forming fine, spherical precipitates. In recrystallized grains, precipitationPrecipitation was delayed and followed the typical morphological sequence, producing large dendritic precipitates. EDS confirmed minimal solute redistribution between grains. Coarsening kinetics were compared to undeformed samples with precipitate populations presenting comparable size and fraction, indicating that deformationDeformation does not significantly affect coarsening. These findings demonstrate that deformationDeformation strongly accelerates precipitation kineticsPrecipitation kinetics without influencing subsequent coarsening, providing insights into microstructural evolutionMicrostructural evolution during thermomechanical processingThermomechanical processing of Ni-based superalloysNi-based superalloy at temperaturesSuperalloy close to solvus temperatures.
Alloy 718Alloy 718 is an important class of Nb-bearing Ni-basedNi-based superalloy superalloysSuperalloy for high-temperatureHigh-temperature applications; however, its service temperature is limited to below 650 °C due to the thermal instability of γ″ precipitates. To understand and improve the creepCreep properties of 718718-type alloys, the creepCreep behaviors of alloy 718Alloy 718 and alloy Ta-718718, strengthened by γ″-Ni3Nb and γ″-Ni3Ta precipitates, respectively, were investigated. CreepCreep tests were conducted at 700 °C under applied stresses of 400 and 500 MPa. While the minimum creepCreep rates were comparable among the specimens, creepCreep acceleration was significantly suppressed in alloy Ta-718718 compared with alloy 718Alloy 718. To further examine the role of the initial γ″ precipitate size, an additional alloy Ta-718718 specimen with a larger γ″ disk diameter ( 24 nm) was prepared by extended aging. The original Ta-718718 specimen had a smaller γ″ disk diameter ( 18 nm), while alloy 718Alloy 718 exhibited a γ″ disk diameter of 27 nm. Despite the γ″ precipitate size of the Ta-718718 (LA) specimen being close to that of alloy 718Alloy 718, it exhibited creepCreep behavior similar to that of the original Ta-718718 specimen. These results indicate that the difference in creepCreep behavior between alloy 718Alloy 718 and alloy Ta-718718 cannot be explained solely by the initial γ″ precipitate size. Rather, γ″ precipitate size evolution—particularly coarsening behavior—remains a dominant factor, while additional contributions from matrix strength and interfacial characteristics are also suggested. The τc analysis provides a useful framework for interpreting the onset of precipitate shearingPrecipitate shearing, although it does not fully account for all contributing factors.
Inconel 706Inconel 706 is a superalloySuperalloy mainly used for very large gas turbine components. Its microstructureMicrostructure is composed of γ′ and γ″ as hardening phases and η phase for some applications to control grain size and to improve creep ruptureCreep rupture life. Studying the η phaseΗ phase precipitation kineticsPrecipitation kinetics in such alloy can be challenging using classical methodologies. Electrical resistivityElectrical resistivity is an efficient in situ method to monitor phase transformation kinetics in the case of γ/γ′ superalloysSuperalloy. However, its effectiveness still needs to be assessed in more complex precipitationPrecipitation sequence such as γ/γ′-γ″- η/δ like in Inconel 706Inconel 706 superalloySuperalloy. Various heat treatmentsHeat treatment were tested using an in-house resistivimeter to study precipitationPrecipitation and dissolution kinetics, covering solution treatmentSolution treatment, cooling rate, and stabilization treatment. The variations in electrical resistivityElectrical resistivity during the heating stage of solution treatmentSolution treatment were attributed to the successive dissolution of the three types of precipitates: γ′, γ″, and η phasesΗ phase. The complete dissolution of η phaseΗ phase occurred after 40 min at 990 °C while at least 2 h 30 are needed at 965 °C. η phaseΗ phase precipitationPrecipitation occurs during slow cooling before reaching the stabilization temperature, which is not the case for fast cooling. Various isothermal treatments were then tested and showed different electrical resistivityElectrical resistivity evolution reflecting different η phaseΗ phase precipitation kineticsPrecipitation kinetics depending on the temperature. Electrical resistivityElectrical resistivity proved to be efficient in monitoring the precipitationPrecipitation and dissolution kinetics of η phaseΗ phase in Inconel 706Inconel 706 during various heat treatmentsHeat treatment, making it highly relevant for addressing industrial challenges.
The AlSuperalloy and NbMechanical properties contentsMicrostructure in polycrystallineAl:Nb ratio Ni superalloysSuperalloy have significant effects on alloy microstructureMicrostructure and properties. Understanding the effect of the Al:Nb ratioAl:Nb ratio is therefore required. Alloys with varying Al:Nb ratiosAl:Nb ratio have been aged at temperatures of 750-850 ^∘ C for 1 to 8 h. The alloy with the lowest Al:Nb ratioAl:Nb ratio was the most prone to δ formation and had the lowest γ ^ ' volume fraction. It also formed γ ^ '' large enough to be observed through scanning electron microscopy after higher temperature and longer duration ageing treatments. The activation energy for diffusion-controlled coarsening of γ ^ ' precipitates was calculated using a Lifshitz-Slyozov-Wagner model, and a trend of decreasing activation energy with increasing Al:Nb ratioAl:Nb ratio was seen. However, extrapolating to longer duration ageing treatments at 825 ^∘ C resulted in an underestimate relative to the observed precipitate diameter, attributed to extensive δ phase formation. The hardnessHardness of the aged alloys is rationalised through the coarsening of γ ^' , the change in γ ^ ' volume fraction including the effect of δ formation, and the presence of γ ^ '' . Tensile testing at 650 ^∘ C showed variations in behaviour with strain rate. Slow strain rates led to environmental embrittlement, with grain boundary δ appearing to increase the strain to failure. Intermediate strain rate tests led to Type C Portevin-Le Chatelier effect serrations and increased strain to failure as the effect of environmental embrittlement decreased. All alloys exhibited negative strain rate sensitivity, although the strain rate at which this occurred varied. These insights into the effect of Al:Nb ratioAl:Nb ratio on the microstructural and mechanical propertiesMechanical properties of these alloys show the significant impact of the compositional choice, and that the ratio of these elements should be carefully considered during alloy designAlloy design.
Additive manufacturingAdditive manufacturing (AM) is gaining momentum for producing high-performance, load-bearing components in critical industries such as oil and gas and energy. Nickel-based superalloysSuperalloy, known for their strength and corrosionCorrosion resistance, are well-suited for extreme environments, however, their adoption via AM, particularly for safety-critical applications, demands robust qualification frameworks to address the unique microstructural and performance challenges introduced by layer-wise fabrication. This study presents a qualification methodology for laser powder bed fusion (PBF) of nickel-based superalloysSuperalloy, using UNS N07718N07718 as a representative material. The approach comprises two phases: (1) a Design Phase, involving metallurgical and mechanical characterization to validate material integrity, and (2) a Performance Phase, assessing resistance to environmental cracking under simulated field conditions. Mechanical testing in the Design Phase included tensile, hardnessHardness, and impact evaluations, alongside chemical verification and microstructural analysis to ensure compliance with required industry standards. In the Performance Phase, slow strain rate testing (SSRT)Slow Strain Rate Testing (SSRT) and high-pressure, high-temperatureHigh-temperature (HPHT) C-ringC-ring tests were performed to evaluate resistance to hydrogen embrittlement and stress corrosionCorrosion cracking in H2S containing service environments. Results show that microstructural characteristics, shaped by AM process parameters and powder properties, significantly influence environmental performance. Variability in cracking resistance underscores the need for controlled processingProcessing and application-specific testing. This work outlines a rigorous path toward qualifying AM-produced nickel-based superalloySuperalloy components for demanding applications and provides a framework adaptable to other alloys and environments.
The use of additive manufacturingAdditive manufacturing processes enables the production of parts with tailored geometries, enabling for example the addition of substructures to large components. This can provide significant savings in material usage reduce lead times for production, which makes AM processes interesting for the aerospace industry. Aerospace components are often subject to maintenance, repairRepair and overhaul procedures to increase usable lifetime, and hence remanufacturing and repairRepair capabilities are an important consideration for the applicability of materials and production processes. Additive manufacturingAdditive manufacturing creates complex microstructuresMicrostructure with properties different to materials produced via traditional manufacturing routes. It is not yet well understood how additively manufactured material responds to repairRepair operations with local material removal and subsequent re-deposition. This study investigates the effect of localised repairRepair operations on the microstructural properties of an Alloy 718718 component manufactured via laserLaser DED directed energy depositionDirected energy deposition with wireWire as feedstock material (DED-LB/w). RepairRepair operations have been carried out using both laser directed energy depositionDirected energy deposition with powder (DED-LB/p) and manual tungsten inert gas (TIG) weldingWelding. The resulting microstructuresMicrostructure show a columnar dendritic grain structureGrain structure with Laves phases precipitates in interdendritic areas. A 3-step solution and age hardening heat treatmentHeat treatment led to δ phase precipitationPrecipitation in interdendritic areas and increased hardnessHardness to >400 HV1 for all material conditions but was unable to completely dissolve Laves phase in TIG welded specimens.
Nickel-based superalloysSuperalloy provide exceptional high-temperature mechanical propertiesMechanical properties which enable a wide range of engineering applications from aerospace turbine engines to land-based industrial gas turbines used for energy production. Additive manufacturingAdditive manufacturing (AM) is making major impacts across structural alloy application in these same industries, enabling supply chain resilience with distributed domestic manufacturing helping original equipment manufacturers avoid massive lead times associated with legacy tooling. Additionally, AM opens new possibilities from a part performance perspective, both by enabling complex geometries that would be impossible with traditional manufacturing, and by enabling customizable parts that can replace assemblies, reducing system complexity. Alloy 718Alloy 718 is a workhorse alloy in this space, however, the temperature range of application of Alloy 718Alloy 718 is limited to 700–750 °C. For many aerospace and energy applications, the next generation of systems design is pushing the limits on temperature, requiring materials with resistance to these higher temperatures. Today, Waspaloy is widely used for applications at 750–850 °C—beyond the limits of 718718 and 718Plus. However, Waspaloy is notoriously difficult to print, with a propensity for strain age crackingStrain age cracking. To enable a printable nickel-based superalloySuperalloy with high-temperature performance comparable to Waspaloy, this work focuses on co-precipitationPrecipitation strengthening from γ′ (Ni3Al) and γ″ (Ni3Nb) nano-precipitates in a compact morphology by precisely designing the composition and process using integrated computational materials engineering (ICME)Integrated Computational Materials Engineering (ICME). This compact morphology enables superior strength, creepCreep resistance, and thermal stability with a lower total volume fraction of γ′, improving printability over other high-temperature alloys with comparable properties.
Cast and wroughtWrought HAYNES 233 alloy was recently developed by Haynes International for applications requiring greater resistance to high-temperatureHigh-temperature oxidationOxidation compared to that of alloys such as 617, 230, or 188 while not compromising the material’s creepCreep performance. It has been verified that the alloy is an aluminaAlumina-former, by design, in contrast to the aforementioned creepCreep-resistant chromia-forming alloys. The alloy’s fabricabilityFabricability (formability, weldabilityWeldability) is adequate. In addition to the targeted combustor can applications in advanced gas turbine engines, chiefly requiring sheet products, certain designs may also utilize bulky components such as seamless ringsSeamless rings. A total of four trial rings (in two different geometries) were forged by the Larson ForgingsForging Co. from 12.5 cm (5″) diameter billet provided by Haynes International. The microstructuresMicrostructure of these rings in the as-forged as well as various annealed conditions were evaluated. Key mechanical propertiesMechanical properties (tensile and creepCreep-ruptureCreep-rupture) were measured in the optimal annealed plus standard 2-step aged condition. These attributes were compared to those of hot rolled and similarly heat-treated Haynes International plate products.
This study systematically investigates the effects ofBoron microalloying boron (B) content (0.02–0.2 wt.
The development of fabricable superalloysSuperalloy with high temperature strength and environmental resistance has long presented a challenge. In particular, the development of aluminaAlumina-forming Ni-basedNi-based superalloy superalloysSuperalloy has historically required sacrificing creepCreep strength and fabricabilityFabricability in exchange for improved environmental resistance above 982 °C, limiting their applications. Originally developed as a precipitationPrecipitation-hardened chromia former, ATI 273ATI 273™ alloy was found to also exhibit the formation of a protective, continuous aluminaAlumina layer at temperatures above 1038 °C while simultaneously exhibiting improved strength and fabricabilityFabricability characteristics compared to conventional aluminaAlumina-forming alloys. To assess the performance of the newly developed Ni-based ATI 273ATI 273™ superalloySuperalloy compared to other legacy Ni-based superalloysSuperalloy, its oxidationOxidation resistance, mechanical propertiesMechanical properties, and microstructural stabilityMicrostructural stability from a 9-metric-ton production heat were investigated and compared to ATI 263™, ATI 6230™, ATI 718718™, ATI 617™, Haynes® 282®, Haynes® 214®, and Haynes® 233® alloys. Results indicate ATI 273ATI 273™ alloy exhibits a unique combination of properties making it attractive for applications requiring long-term service at temperatures between 760 and 1149 °C.
Variations in microstructureMicrostructure evolution in response to heat treatmentHeat treatment were investigated as a part of the 2025 Additive ManufacturingAdditive manufacturing Benchmark Test Series in laser powder bed fusion Alloy 625Alloy 625 materials with key differences in chemical composition. Materials were deposited with identical process parameters to isolate the effects of alloy composition on precipitate formation. In an as-deposited alloy with a 0.058
Ideally, an additively manufactured component could be fabricated on any laser powder bedLaser Powder Bed Fusion (PBF-LB) fusion (PBF-LB) platform and achieve consistent performance. However, there are inherent differences in the machine technology, such as laser optics trains, recoating mechanisms, and gas flow, along with differences in the default processingProcessing parameters used in each system. This work presents a round robin study for SuperalloySuperalloy 718718 commonly referred to as Inconel 718Inconel 718 (IN718) fabricated across six different PBF-LB platforms with documented processingProcessing data pedigree. Powder characteristics, composition, surface roughness, porosity, microstructureMicrostructure, and tensile behaviorTensile behavior are presented for the as-built condition, and after two different standard heat treatmentsHeat treatment are applied. The as-built condition showed a typical strength-ductilityDuctility trade-off between platforms. Elongation proved to be sensitive to the heat treatmentHeat treatment with the higher temperature HT2 showing an increase in elongation with no decrease in strength when compared to HT1. Results from this project help support the viability of cross-platformCross-platform fabrication by attempting to link the process-structure–property relationships in PBF-LB IN718 for different platforms.
The microstructureMicrostructure gradient and microstructureMicrostructure-dependent mechanical propertiesMechanical properties of electron beam welded Ni-basedNi-based superalloy superalloySuperalloy were systematically investigated. During the weldingWelding process, the elevated temperature, steep temperature gradientTemperature gradient, and severe heating/cooling rate led to obvious changes in grain, γ′ particles, carbides and dislocation configurations across the weld joint. Moreover, the local deformationDeformation behavior in different regions across the weld joint was investigated by the in-situIn-situ SEM micro-tensile test in the scanning electron microscope (SEM) and analyzed by the micro digital image correlation (DIC). As a result, the microstructureMicrostructure-dependent mechanical propertiesMechanical properties, such as micro-hardnessHardness, Young’s modulus and yield strength (YS), diversified significantly from weld center to base material. Furthermore, the performance of post-weld heat treatmentHeat treatment (PWHT) resulted in coarsening of intragranular γ′ particles and precipitationPrecipitation of intergranular M23C6 carbides. The yield strength (YS) and ultimate tensile strengthTensile strength (UTS) of weld joint were increased by the enlarged γ′ particles in grains, while the ductilityDuctility of weld joint was enhanced by the precipitated M23C6 carbides at grain boundary, especially at elevated temperature. This work provides a high-throughput measurement method for microstructureMicrostructure-dependent properties and guidance for optimizing EBW superalloySuperalloy microstructuresMicrostructure and mechanical propertiesMechanical properties.
Artificial intelligence technologies have significantly advanced the development of materials science, however, their application and exploration in the field of additive manufacturingAdditive manufacturing superalloysSuperalloy remain relatively limited. Herein, we propose a set of methodologies for sample preparation, composition analysis, and defect characterization of additive manufacturingAdditive manufacturing superalloysSuperalloy, which are designed to collect experimental data (>1300 data points) related to such alloys. By training machine learningMachine Learning (ML) models on the acquired data, a high-precision defect prediction model for additive manufacturingAdditive manufacturing superalloysSuperalloy is established (R2 > 90
