Ni-based Alloys Research Articles

Preparation of a novel laser cladding Ni-based alloy with promising applications in high-temperature conditions: Genetic design, multi-phase evolution, and synergy mechanism

Developing novel Ni-based alloys is crucial for remanufacturing key friction parts at 800-1200 ℃ in metallurgical industry with multiple failure mechanisms, such as wear, corrosion, and adhesion. This paper adopts genetic algorithm to design high-temperature Ni-based alloy with three genetic structures of wear resistance, anti-corrosion, and self-lubricating. By combining simulation calculation and experimental methods, the evolution of the three genetic structures of the laser cladding alloy and the performance strengthening mechanism were deeply studied. The laser clad Ni17Cr10Co7Al5Ti3W2C1S sample of optimized composition had three genetic structures: Cr7C3/TiC wear resistance phases, γ/γ′ anti-oxidation and anti-corrosion phases, Ti2SC/TiS self-lubricating phases. Compared with Cr28Ni48W5 superalloy, the wear rate of the optimal sample was 2.31×10-5 mm3/(N·m) under 800 ℃ friction condition, and reduced by 97%. The friction coefficient of the sample at high temperature was 0.2, approximately half of the substrate alloy, and the self-lubricating performance was significantly improved. Electrochemical tests indicated that the polarizing potential of the sample was -0.16 VSCE in 3.5wt. % NaCl solution. The mechanism of three genetic structures evolution and synergistic enhanced wear resistance, anti-corrosion, and self-lubricating properties were elaborated. Specifically, the key gene of Ti2SC plays a profound role in improving the high-temperature wear resistance and self-lubricating performance of the novel laser clad Ni-based alloy sample. These findings present a novel avenue of material design and preparation for laser additive manufacturing and remanufacturing of key friction parts with high-performance at 800-1200 ℃ in complex metallurgical working conditions.

Influence of Ti element on the microstructure and crack of modulated WC-strengthened Ni-based alloy coatings by laser cladding

For laser cladding of WC reinforced Ni50A Ni-based alloy coatings can cause cracks and porosity. Cracks and pores will restrict the application and performance of the coating. In order to improve the crack condition of the coating, the influence of alloying element Ti on the crack was investigated by introducing it. Cracks in the coatings were eliminated. When the addition amount of Ti is 3wt%, the morphology and properties of the coating are the best. The phase composition, microstructure, elemental distribution and grain orientation of the coatings were characterised using X-ray Diffractometry (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectrometer (EDS), Electron Backscatter Diffraction (EBSD) and Transmission Electron Microscopy (TEM). The hardness and abrasion resistance of the coatings were tested using microhardness tester and friction tester. The results show that a large number of second phases are present in the coating when Ti particles are not added. The introduction of Ti element disperses the localised stresses in the Ni50A-WC coating. The macroscopic morphology of Ni50A-WC coating was improved. The introduction of Ti reduced the area of the second phase within the coating. The introduction of Ti generated TiC/TiWC2 in situ. However, the introduction of Ti increased the dilution rate and decreased the strength of the coating. Therefore, the microstructure of the coating can be controlled and the macroscopic defects of the coating can be improved by adjusting the addition ratio of Ti elements.

Effect of heat treatment on the microstructure of additive manufactured Ni-based hardfacing alloy deposits on stainless steel

Ni based (NiCrFeSiBC) hardfacing alloy was deposited on 304 L SS build plate by laser rapid manufacturing (LRM) process. As-deposited specimen showed nearly a precipitate free zone at the interface, grain boundary (GB) precipitation in stainless steel up to 10 µm, thin dilution layer (∼60 µm) followed by formation of zones with distinct microstructure, microhardness and microchemistry in the deposit. To investigate the effect of thermal exposure on the interface microstructure, deposits were heat treated in the temperature range of 823-1123 K for 5-100 h. Up to 923 K, structure of the LRM deposits resembled that of as-deposited specimen. A planar interface region devoid of precipitates was present even after thermal exposure up to 923 K. With further increase in the temperature, formation of CrB precipitates with globular morphology was observed along the deposit/build plate interface with simultaneous increase in hardness. Thermal exposures beyond 923 K promoted coarsening of M7C3 and Cr2B precipitates. Diffusion of carbon and boron from the deposit to the build plate promoted the grain boundary precipitation of chromium carbides up to a maximum distance of ∼1000 µm for the highest temperature of 1123 K.

Simulation and experimental study on temperature field and flow field of laser cladding high-temperature Ni-based alloys

Abstract The multiphase liquid's development during the laser cladding process involves complex processes such as energy input, mass input, heat transfer, multi-phase liquid flow, and rapid solidification. Based on the coupled theory of temperature field and velocity field, a multi-field coupling model for Ni-based high-temperature alloy on the surface of 40Cr has been established. Throughout the modeling procedure, the surface tension coefficient's impact o.During the modeling process, the effect of the surface tension coefficient on the flow velocity of the molten metal in the melt pool is considered, along with the tracking of the gas/liquid free boundary through the use of the dynamic mesh technique. By comparing experimental and simulation results, it is found that the prediction error of the model ranges from -11.79% to 12.08%, demonstrating that the model has certain explanatory and predictive capabilities for laser cladding of Ni-based high-temperature alloys

Performance Evaluation of a 40-kWth Prototype Counterflow Particle-sCO2 Fluidized Bed Heat Exchanger

Particle-sCO2 heat exchangers (HXs) can couple particle-based thermal energy storage for concentrating solar power (CSP) plants with recompression closed Brayton power cycles (RCBC) to enable continuous dispatchable renewable electricity. RCBC firing temperatures >700°C require HXs with expensive Ni-based alloys, requiring HX designs to reduce mass with high overall heat transfer coefficients UHX to meet CSP primary HX cost. To enhance UHX, mild bubbling fluidization with downward particle flows and upward fluidizing gas flows can achieve particle-wall heat transfer coefficients hT,w >800 W m-2 K-1 with CARBOBEAD HSP 40/70. To assess how high hT,w with mild particle fluidization impacts UHX, a 40-kWth particle-sCO2 HX with 12-parallel narrow-channel fluidized beds was assembled and tested to particle inlet temperatures up to 530 °C. Tests show reliable steady-state HX operation by maintaining fluidized particles in a freeboard zone above the parallel channels, but axial dispersion mixes partially cooled particles up from the fluidized channels with particles fed into the freeboard zone from the feed hopper. This mixing lowers the effective bed temperatures and the driving force for heat transfer to counterflowing sCO2 in microchannelled walls. Measured UHX based on particle inlet temperature never exceeded 205 W m-2 K-1. The trade-off between increased hT,w, and increased vertical dispersion with gas flows resulted in only small improvements in UHX after the onset of fluidization. Dispersion was incorporated into HX design and performance models that used hT,w correlations fitted to single-channel heat transfer tests. Model results show that reducing dispersion leads to higher particle wall heat transfer.

Wear Resistance Design of Laser Cladding Ni-Based Self-Fluxing Alloy Coating Using Machine Learning.

To improve the collaborative design of laser cladding Ni-based self-fluxing alloy (SFA) wear-resistant coatings, machine learning methods were applied. A comprehensive database was constructed from the literature, linking alloy composition, processing parameters, testing conditions, and the wear properties of Ni-based SFA coatings. Feature correlation analysis using Pearson's correlation coefficient and feature importance assessment via the random forest (RF) model highlighted the significant impact of C and B elements. The predictive performance of five classical machine learning algorithms was evaluated using metrics such as the squared correlation coefficient (R²) and mean absolute error (MAE). The RF model, which exhibited the best overall performance, was further combined with a genetic algorithm (GA) to optimize both composition and processing parameters collaboratively. This integrated RF-GA optimization system significantly enhanced efficiency and successfully designed multiple composition and process plans. The optimized alloy demonstrated superior wear resistance with an average friction coefficient of only 0.34, attributed to an enhanced solid solution strengthening effect (110 MPa) and increased hard phase content (52%), such as Ni₃Si, CrB, and NbC. These results provide valuable methodological insights and theoretical support for the preparation of laser cladding coatings and enable efficient process optimization for other laser processing applications.

Study on the effect of stress redistribution in different notched specimens of DD6 on the life of combined high and low cycle fatigue under high temperature

Under combined high and low cycle fatigue (CCF) loading, the multi-axial stress state induced by geometric discontinuities of different notch forms under the same stress amplitude can result in significant differences in fatigue performance of DD6 alloy. Therefore, it is of great importance to study the CCF behavior of Ni-base single-crystal alloy samples with differing notch geometries at the high temperatures. In order to obtain an approximate CCF lifespan, different stress amplitudes need to be applied to DD6 specimens with different notch forms. In this study, two kinds of notched DD6 plate specimens with [001] orientation were studied by CCF test at 760 °C, and the amplitudes of stresses were acquired under the same service life level. The effect of stress redistribution, in particular stress triaxiality, was evaluated on CCF lifetime of the DD6 specimens. A damage model with anisotropy considering stress triaxiality effect was suggested. The results indicated that the conventional stress–strain variables could not reflect the trend of CCF lifetime for different geometrical notched DD6 specimens, whereas the stress triaxiality at the CCF load peak could. A modified Basquin model was introduced for predicting CCF life according to the stress triaxiality at the peak loading. It can accurately and efficiently estimate the CCF life of two kinds of notched DD6 plate specimens, and the life prediction results fall within a scatter band of ±3 times of fatigue life.

Creep Lifetime Prediction of Alloy 617 Using Black Box Machine Learning Approach

Abstract This study explored the application of black box machine learning (ML) to build high throughput models that predict the creep response of Ni-based Alloy 617. Black box ML refers to highly complex machine learning algorithms that generate outputs from inputs without an interpretable internal process. The rapid implementation of suitable heat of alloys into targeted service is impeded by the extended qualification process involving chemistry-processing-structure-performance assessment. The ASME B&PV Code III outlines the requirement of 10,000 h of creep testing before each heat can be qualified for service and 30,000 h for heats that exhibit metastable phases. There is a critical need to shorten the development-to-deployment timeline for heats of an alloy at specific applications. Recent advancement in ML offers the ability to identify correlations in data which is difficult to elucidate by other approaches. To that end, black box ML is employed to expedite the HEAT qualification of Alloy 617 and predict performance from HEAT chemistry out to an unprecedented timescale. In this study, creep data for Ni-based Alloy 617—a solid solution strengthened material is gathered from a wide range of data sources. The alloy chemistry, phases, precipitates, and microstructural features are analyzed to obtain the key strengthening mechanism. Service conditions, mechanical properties, chemistry, and chemical ratios are provided as potential input features. The Pearson correlation coefficient with a 95% confidence bound is employed for input feature screening where poorly correlated inputs are eliminated to speed up the ML process and prevent under- and/or over-fitting of predictions. In the ML algorithm, the selected input features are regarded as predictors, and rupture is regarded as the response. An algorithm evaluation is performed where 20 ML algorithms are trained with the training set. The three-layered neural network (NN) was observed to be the best algorithm for the given data based on statistical rationale. The NN accurately predicts rupture across a range of isotherms and data sources. The interpolative and extrapolative predictions are in compliance with ECCC V5 guidelines. A post-audit validation exhibits neither under- nor over-fitting and confirms the applicability of NN algorithms to unseen data. The black box ML provides a pathway to predict the performance directly from chemistry and opens avenues to rapid heat qualification.

Slip transfer and crack initiation at grain and twin boundaries during strain-controlled fatigue of solution-hardened Ni-based alloys

Slip transfer/blocking at grain and twin boundaries as well as preferential fatigue crack nucleation locations were studied in two solution-hardened Ni-based alloys (Inconel 600 and Hastelloy C276) deformed under strain-controlled, fully-reversed cyclic deformation in the low-cycle fatigue regime. Electron backscatter diffraction-based slip trace analysis was used to identify the active slip systems after interrupted fatigue tests. It was found that the Luster-Morris parameter m′=0.6 was an accurate geometrical criteria to discriminate between slip transfer and blocking at grain and twin boundaries. Moreover, it was found that fatigue cracks initiation was always intergranular and cracks were nucleated at grain and twin boundaries when the slip transfer across was blocked. The probability of crack nucleation increased with the misorientation angle and was independent of the grain size. This behavior was associated with the development of stress concentrations at grain and twin boundaries as well as triple junctions in which slip was blocked and is different from previous reports on fatigue crack nucleation in Ni-based superalloys deformed, in which the slip system parallel to the TB in the parent grain was suitably oriented for slip. This contrast in the fatigue crack nucleation sites between both types of Ni alloys were attributed to the differences in the degree of strain localization and show how this factor controls damage nucleation in polycrystals.

Bayesian optimization of 7-component (AlVCrFeCoNiMo) single crystal alloy’s compositional space to optimize elasto-plastic properties from molecular dynamics simulations

Abstract Exploring the vast compositional space of high-entropy alloys (HEAs) promises materials with superior mechanical properties much needed in industrial applications. We demonstrate on the 7-component alloy AlVCrFeCoNiMo system with randomly ordered atoms that this exploration of the compositional space can be accelerated by combining molecular dynamics simulations with Bayesian optimization. Our algorithm is tested on maximizing the shear modulus, resulting in pure Mo, an unsurprising result based on Mo’s large density. Maximizing the yield stress results in Co-, Cr- and Ni-based alloys with the optimal composition varying depending on the presence of defects within the crystal. Finally, we optimize the plastic behaviour by aiming for high stresses while minimizing the deformation fluctuations, and find that a predominantly NiMo alloy’s high lattice distortions ensure a smooth stress response. The results suggest that mechanical properties of 2- to 4-component alloys with optimized composition may be superior to those of equiatomic HEAs without short-range order.

Corrosion behaviors of Ni-based GH3625 alloy in molten solar salt

The high-temperature corrosion behavior of GH3625 alloy was investigated in molten solar salt (NaNO3/KNO3 (60/40 mass %)) under an argon atmosphere. The dynamic corrosion rate increased with rising temperature, from 4.3 to 21.6 μm/y. Through the sophisticated sample preparation on the oxidation layer using FIB technology, and the fine characterization using TEM analysis, the corrosion type shows no influence on the oxide types. Meanwhile, the oxidation layers were discovered to be constituted by the Cr2O3 particles in the matrix, a depleted region of Cr, a Cr2O3 layer, a layer consisting of NiO and Cr2O3 particles, and a dense NiO layer from the matrix to the outer layer. The Cr2O3 was found to form before NiO. The NiO was confirmed to protect the alloy during the corrosion process. A narrow depletion zone of Cr was discovered. The silicon was indicated to be harmful to the corrosion resistance. This work provides insight into the corrosion mechanism of GH3625 in molten solar salt.

Enhancing the Accuracy and Generality of the Debye–Grüneisen Model: Optimizing the Volume Dependence for Accurate Predictions Across Varied Compositions

In this work, we have introduced an optimized Debye-Grüneisen model that revolutionizes the determination of the Debye temperature and Grüneisen parameters. Unlike conventional methods, our model requires only the 0 K energy volume data for a material as input, eliminating the need to determine the bulk modulus and its pressure derivative, which often pose challenges due to numerical uncertainties. This unique feature sets our model apart from existing approaches and streamlines the process, enabling accurate predictions of thermal expansion behavior across various materials. To demonstrate its effectiveness, we showcase its excellent agreement with measured coefficients of thermal expansion (CTE) for the nickel-cobalt-chromium-aluminum-yttrium (Ni-Co-Cr-Al-Y) bond-coating system. Additionally, we apply our approach by conducting a high-throughput search for potential bond-coating materials among 90,000 compositions within the aluminum-cobalt-chromium-iron-nickel (Al-Co-Cr-Fe-Ni) system. From this extensive search, four compositions are synthesized, and the measured CTE values agree very well with theoretical predictions, hence validating our approach. The current optimized Debye-Grüneisen model combined with Density Functional Theory (DFT)-based thermodynamic database enables reliable and efficient high-throughput calculations of CTE of Ni-based alloys without expensive phonon calculations.

Effect of Equivalent La and Ce Substitution for Y on the Structure and Properties of A2B7-Type La–Y–Ni-Based Hydrogen Storage Alloys

Effect of Equivalent La and Ce Substitution for Y on the Structure and Properties of A₂B₇-Type La–Y–Ni-Based Hydrogen Storage Alloys

Influence of composition and temperature on oxide film formation for Fe-Cr-Ni alloys in simulated PWR primary water

ABSTRACT The growth of oxide films on Fe-Cr-Ni alloys in simulated pressurized water reactor (PWR) primary system environments was investigated, with focus on the influence of alloy composition and temperature. Oxide film thicknesses were measured for 90 specimens prepared from compact tension (CT) test pieces. Cross-sectional observations were also conducted on coupon specimens using scanning transmission electron microscopy (STEM). The behavior of Ni-based alloys, specifically Alloy 600, and Fe-based alloys, specifically Type 316 stainless steel, were compared. Ni-based alloys exhibit superior corrosion resistance due to slower Fe diffusion kinetics compared to Fe-based alloys, leading to the formation of a nickel-enriched protective layer at the metal-oxide interface. The oxidation rates of Ni-based alloys follow an Arrhenius-type temperature dependence. In contrast, Fe-based alloys show a more complex temperature-dependent behavior, with reduced oxidation rates at higher temperatures that are likely due to changes in oxide dissolution. Higher chromium concentrations in both alloy types improve the protectiveness of the oxide film towards corrosion by forming a more compact inner oxide layer. The study identifies three primary factors influencing oxide film growth: reactions at the metal-oxide interface, diffusion within the oxide layer, and processes at the oxide-solution interface. The relative significance of these processes varies depending on the alloy composition and temperature.

A multiscale model for efficiently simulating laser powder bed fusion process with detailed microstructure and mechanical performance results

Numerical simulation is regarded as an important method for studying the mechanisms of additive manufacturing (AM), especially in building a multiscale simulation model. However, the conversion of physical phenomena and parameters across scales is complex, and the number of simulation elements often changes extremely, leading to an inherent conflict between simulation accuracy and efficiency. Therefore, this work introduces a model that balances the need for detailed grain morphology and overall simulation efficiency, to investigate the relationship between process parameters, microstructure, and mechanical performance during Inconel 718 laser powder bed fusion (L-PBF) process. The cellular automata - finite element method (CA-FEM) was used to simulate the melt pool forming and predict the microstructure evolution. Based on the CA result, the tensile process was simulated through crystal plasticity-finite element method (CP-FEM). Specially, the CA-FEM model was simplified and sliced layer-by-layer to reduce simulation time and data storage, supporting parallel computation. The prediction time for the microstructure growth of millions of elements was less than 1.5 h. The CP-FEM model was simplified by reasonably reducing elements in the representative volume element (RVE) model, improving the simulation efficiency by 73 %. The simulation results were validated through EBSD observation and tensile tests, showing good agreement with experimental results, with the final simulation error for mechanical performance not exceeding 10 %. The effects of process parameters on microstructure and mechanical performance were comprehensively discussed. This model supports the optimization of L-PBF process parameters for Ni-based alloys and provides a reference for improving the efficiency of multiscale simulations for other AM processes and materials.

Understanding the grain refinement and residual stress formation mechanisms of a Ni-based alloy during machining processes

Ni-based alloys are important materials for many industries, microstructure of the sub-surface regions of these alloys can be refined during machining processes, affecting both their machinability and service performance. Several mechanisms have been proposed to explain the machining-induced microstructure refinement of these alloys, however, sound evidences to support them are still lacking. In this research, microstructure characterization with an emphasis on the micro-texture and defects was conducted on milled surfaces of a Ni-based alloy, to promote in-depth understanding of the grain-refinement process. A nano-crystalline layer consisted a topmost region with randomly-orientated grains and annealing nano-twins and a textured region beneath it with deformed microstructure was observed in the cross-section of the alloy with the help of high resolution orientation determination techniques. These observations provide additional evidences to support the recrystallization induced grain-refinement mechanism of the nano-grains. It is also suggested that recrystallization was a by-product of the shear deformation occurred during the milling process, supported by the observation of the clear boundary between the nano-grain layer and its beneath deformed region. The deformed region was refined as a result of mechanical twining and twin-intersections, leading to significant fluctuations of the residuals stresses.

Effect of Cr, Al and Mo additives on the wetting characteristics of molten Ni on (Ti, Zr, Hf, Nb, Ta)C high entropy ceramics

For the first time, the wetting behavior of the (Ti, Zr, Hf, Nb, Ta)C) high entropy carbide ceramics by molten Ni-based alloys was investigated using a sessile drop technique in a vacuum environment. Adding 10 wt% of Cr, Mo, or Al into Ni resulted in final contact angles of 14°, 10°, and 14° on the (Ti, Zr, Hf, Nb, Ta)C substrate, respectively. The interaction mechanism between (Ti, Zr, Hf, Nb, Ta)C and Ni-based alloys occurs in two stages: the dissolution and interaction of the elements Ti, Zr, Hf with the alloys and the dissolution of NbC and TaC at the grain boundaries. SEM observations revealed that Cr and Al additives do not interact with carbides, while Mo was dissolved in carbides. Due to the low contact angle, minimal interaction region between alloy and ceramic, and short time of drop spreading, NiAl alloy is proven to be a promising binder for the HEC-based composites.

Fabrication and characterization of novel high-efficiency and high-durability neutron-absorbing Ni-based alloys

New neutron-absorbing Ni-based functional alloys that depend on the gadolinium and dysprosium neutron absorption units were fabricated using vacuum induction melting. The effects of Gd and Dy contents on the microstructure characteristics and properties of Ni-based alloys were investigated. Adding Gd, Dy, and Gd + Dy into Ni-based alloys formed Ni5Gd, Ni5Dy and Ni5(Gd,Dy), respectively, and their volume fraction increased with increasing of Gd/Dy content. Different type of elements, Gd or Dy, had no obvious influence on mechanical properties and corrosion resistance, while the amount of Gd and Dy elements played an important role. The shielding properties were calculated by the Monte Carlo method, and the alloys possessed high efficiency and high durability performance due to the high contents of Gd and Dy elements. The developed alloys are expected to be good functional materials for use in the field of nuclear shielding.

Enhanced long cycling durability of Ce2Ni7-type single-phase Sm–Mg–Ni-based hydrogen storage alloys for nickel metal hydride batteries

La–Mg–Ni-based superlattice structure alloys are promising negative material candidates for nickel metal hydride (Ni-MH) batteries, but their application is challenged by cycling life. Herein, we propose Sm–Mg–Ni-based alloys beyond La–Mg–Ni-based alloys to promote long-term durability. Specifically, Ce2Ni7-type single-phase Sm0.58La0.25Mg0.17Ni3.26Al0.18 and Sm0.54La0.29Mg0.17Ni3.26Al0.18 alloys have been obtained, delivering significantly high-capacity retention rates over 70 % after 500 cycles at a 1C charge and discharge rate. Furthermore, the alloy's discharge ability has been optimized via manipulating Sm/La ratios, of which its effect on the structure and electrochemical properties is detailly studied. It is found that the discharge capacity of the Sm0.58La0.25Mg0.17Ni3.26Al0.18 alloy with a higher Sm/La ratio outperforms the Sm0.54La0.29Mg0.17Ni3.26Al0.18 alloy. However, the low Sm/La ratio Sm0.54La0.29Mg0.17Ni3.26Al0.18 alloy is favorable for discharge ability at a high-rate current rate and features lower plateau pressure and enthalpy change compared with Sm0.58La0.25Mg0.17Ni3.26Al0.18. The work is expected to offer new insights into the composition design of hydrogen storage alloys with long cycling life for Ni-MH batteries.

Co-evolution of M23C6 precipitates and cavities in a boron-free Ni-based alloy GH3617 under high-temperature He ion irradiation: Effects on cavity swelling and mechanical properties

Ni-based alloys are promising materials for advanced nuclear reactors operating at high temperatures due to their exceptional resistance to high temperatures and corrosion. Understanding the synergy of phase stability and helium effects is crucial for assessing the long-term performance and reliability of these alloys in advanced nuclear reactors. This study has investigated the co-evolution behavior of M23C6 precipitates and cavities in a boron-free solid solution strengthened Ni-based alloy GH3617 under high-temperature He ion irradiation, and its impact on alloy swelling and mechanical properties, by He ion irradiation experiments with the highest fluence of 1 × 1017 He/cm2 up to 800 °C. Transmission Electron Microscopy (TEM) and Nanoindentation are employed to investigate microstructural evolution and mechanical properties, respectively. The findings show that at room temperature and 500 °C, cavities and dislocation loops were the dominant irradiation defects, whereas at 800 °C, the density of cavities and dislocations reduced while the formation of M23C6 precipitates increased. These precipitates act as effective trapping sites for He and point defect, leading to cavity formation at the interfaces or within the precipitates. Moreover, increased irradiation fluence accelerates the co-evolution process, resulting in an increase in the density and size of both precipitates and cavities, ultimately leading to enhanced swelling. The {111} planes are favored interfaces between intragranular M23C6 precipitates and the matrix due to their minimal misfit, while the preferred interface planes between cavities with octahedral or cubo-octahedral shapes and the precipitate/matrix are also {111}, owing to their lower surface energy as well. The co-evolution of cavities and precipitates was found to influence mechanical properties, resulting in an irradiation hardening effect at lower fluences, while softening at higher fluences. This study provides novel insights into the degradation mechanisms of Ni-based alloys under coupling effect of He and high-temperature irradiation.