Fracture Surface Morphology Research Articles

ZnO/ITO, Sn and Cu Doped ZnO/ITO Films as an Photoanode for Solar Cell: Production and Characterizations

Undoped ZnO and Sn- and Cu-doped ZnO thin films were fabricated on ITO substrates via the SILAR method for this study. The films were then subjected to structural, surface, optical, and electrical characterization. The undoped ZnO thin films displayed a spherical surface morphology, while the Sn-doped ZnO thin films exhibited a nano-flower surface morphology. On the other hand, the Cu-doped ZnO thin films demonstrated a relatively thicker and flat layer, as well as a fractured surface morphology that resulted in voids. The level of crystallization and transmittance values augmented upon doping. With Cu doping, n-p heterojunction structure was obtained from ZnO/ITO films. Hence, it is inferred that the generated Cu doped ZnO/ITO films can serve as alternative transparent conductive films (TCO) due to their low resistivity.

High strength diffusion bonding of Ti2AlNb to GH4169 with (TiZrHfNb)95Al5 high entropy interlayer

A high entropy interlayer (TiZrHfNb)95Al5 was designed for vacuum diffusion bonding of Ti2AlNb to GH4169. The influence of bonding temperature on the interfacial microstructure morphology, mechanical properties and fracture behaviour of the resultant joints was investigated. The evolution of microstructure and fracture mechanism were revealed. The typical interface microstructure of Ti2AlNb/B2/Solid solution/(Ti, Zr, Hf)2(Ni, Nb)+(Ti, Zr, Hf)(Ni, Nb)+(Ti, Zr, Hf)(Ni, Nb)2+Solid solution/(Ti, Zr, Hf)(Ni, Nb)+(Cr, Ni, Fe)ss/(Cr, Ni, Fe)ss/Cr-rich(Cr, Ni, Fe)ss/Ni-rich(Cr, Ni, Fe)ss/GH4169 was formed. As the bonding temperature increased, the thickness of interfacial reaction layer gradually increased, and the shear strength gradually increased until 980 °C, then decreased sharply. The highest shear strength reached 376 MPa at 980 °C for 90 min. The highest microhardness region of 11.79 GPa existed on the GH4169 side, which was mainly composed of (Ti, Zr, Hf)(Ni, Nb) and (Cr, Ni, Fe)ss phases. Meanwhile, the elastic modulus dramatically changed interface formed near this region. The fracture surface morphology indicated typical brittle fracture characteristics such as cleavage steps, transgranular fracture and intergranular fracture. According to the fracture analyses, major cracks initiated in the (Ti, Zr, Hf)(Ni, Nb) phase+(Ti, Zr, Hf)2(Ni, Nb) phase and gradually extended to the (Cr, Ni, Fe)ss phase. Thus, the major crack emerged region was located at the elastic modulus dramatically changed interface.

Experimental Study of Direct Shear Properties of Anisotropic Reservoir Shale

Understanding the shear mechanical properties of shale reservoirs is of great significance in the study of the formation stability around horizontal shale wells and the propagation and evolution of fractures for shale fracturing. However, the existing direct shear test results are limited due to small sample sizes and low shear rates. Based on previous experimental research results, the mechanical properties of anisotropic reservoir shale in direct shear tests with different experimental conditions were explored in this study. It was found that the shear mode, shear strain rate, and normal stress have a significant impact on the deformation and failure characteristics of shale. The peak shear displacement, peak shear strength, and shear stiffness of shale present an increasing trend of fluctuation, with an increase in the bedding angle. The peak shear strength of shale decreases with an increase in the shear strain rate, and this decrease trend descends with an increase in the shear strain rate. The shape of the shear fracture zone and the shear fracture mode of shale exhibit bedding effect characteristics. The fractal dimension of the shale shear fracture surface morphology shows a trend of fluctuation with the variation in the bedding angle. Further, the shear strain rate was found to play a dominant role in the fractal dimension of the shear fracture surface. The larger shear strain rate strengthens the bedding effect of the roughness for the shear fracture surface morphology. The results of this study provide a theoretical reference for determining the engineering geomechanics characteristics of shale reservoirs.

Compatibilization of Polyamide 6/Cyclic Olefinic Copolymer Blends for the Development of Multifunctional Thermoplastic Composites with Self-Healing Capability.

This study investigated the self-healing properties of PA6/COC blends, in particular, the impact of three compatibilizers on the rheological, microstructural, and thermomechanical properties. Dynamic rheological analysis revealed that ethylene glycidyl methacrylate (E-GMA) played a crucial role in reducing interfacial tension and promoting PA6 chain entanglement with COC domains. Mechanical tests showed that poly(ethylene)-graft-maleic anhydride (PE-g-MAH) and polyolefin elastomer-graft-maleic anhydride (POE-g-MAH) compatibilizers enhanced elongation at break, while E-GMA had a milder effect. A thermal healing process at 140 °C for 1 h was carried out on specimens broken in fracture toughness tests, performed under quasi-static and impact conditions, and healing efficiency (HE) was evaluated as the ratio of critical stress intensity factors of healed and virgin samples. All the compatibilizers increased HE, especially E-GMA, achieving 28.5% and 68% in quasi-static and impact conditions, respectively. SEM images of specimens tested in quasi-static conditions showed that all the compatibilizers induced PA6 plasticization and crack corrugation, thus hindering COC flow in the crack zone. Conversely, under impact conditions, E-GMA led to the formation of brittle fractures with planar surfaces, promoting COC flow and thus higher HE values. This study demonstrated that compatibilizers, loading mode, and fracture surface morphologies strongly influenced self-healing performance.

Establishment of a Uniaxial Tensile Fracture Inversion Model Based on Fracture Surface Reconstruction (FRASTA)

In order to infer the load on the component after the experimental uniaxial tensile fracture inversion model based on cross-sectional reconstruction, (FRASTA) was proposed to infer the load on the tested components. This model can combine the fracture surface characteristics of experimental specimens to reconstruct the fracture surface morphology and invert the fracture process of uniaxial tensile specimens. Based on the assumption of rectangular rod fracture, a quantitative inversion model for a unidirectional stress load based on dissipative plasticity characteristics was established, and the inversion results based on cross-sectional reconstruction were compared with the experimental measurement results. The results indicate that when only considering the unidirectional stress state, the two have a high degree of consistency, with a maximum measurement error of 5.3%, fully verifying the accuracy of the fracture surface reconstruction and inversion model.

АНАЛИЗ И УСТАНОВЛЕНИЕ ПРИЧИН РАЗРУШЕНИЯ ТЯЖЕЛОНАГРУЖЕННЫХ ЗУБЧАТЫХ ПЕРЕДАЧ

The destruction of gears occurs due to various reasons, first, connected with violation of manufacturing technology at different stages, poor quality assembly of the gear or the whole mechanism, as well as exceeding the specified operating loads. The aim of the study was to establish the causes of failure of the top drive gears in the drilling rig based on the mechanical and structural characteristics obtained by generally accepted methods, collectively used to assess the nature of the resulting damage. In order to analyze the compliance of the gear manufacturing quality with the operational requirements and to identify the cause of their failure, we carried out complex studies, including microstructural analysis of the gear metal, determination of its chemical composition and mechanical properties, as well as the study of the fracture surface morphology using scanning electron microscopy. As a result, we found that the gears failed due to a violation of the manufacturing technology in terms of wrong heat treatment.

The role of hydrogen in promoting differences in fatigue crack growth rates observed in Type 304/304L stainless steel at elevated temperature

Hydrogen has been postulated to affect fatigue crack growth rates (FCGRs) in Type 304/304L stainless steel during exposure to high purity water (HPW) environments at elevated temperature. To assess this mechanism, FCGR testing was performed at elevated temperature (260°C) in air and pressurized hydrogen gas. Initial results indicate the measured FCGRs in hydrogen are up to 8x lower than those measured in air under comparable fatigue loading conditions. Post-test evaluation of compact tension specimens indicates crack mouth opening displacements and fracture surface morphologies generated in hydrogen that are consistent with those generated in HPW environments. Observations of crack tip blunting suggest the reduced FCGRs in elevated temperature hydrogen occur due to a decrease in the effective ΔK. Finite element plasticity modeling, using a hydrogen-dependent nonlinear kinematic hardening approach, supports the hypothesis that crack tip blunting and retarded FCGRs are due to a hydrogen-based change in cyclic behavior (e.g. cyclic creep) occurring ahead of the fatigue crack tip.

Effects of Annealing Temperature on Microstructural Evolution and Mechanical Properties in Cold-Rolled High-Nitrogen Austenitic Steel

High-nitrogen austenitic steel (HNS) cold-rolled with a reduction rate of 25% was subjected to an investigation of the effect of annealing temperature on microstructural evolution, tensile properties and the variation in fracture surface morphology. In cold-rolled HNS, matrix recovery occurred at an annealing temperature of 600 °C, and recrystallization was locally initiated at an annealing temperature of 800 °C. The 0.2% offset yield strength (0.2% YS) and ultimate tensile strength (UTS) were almost constant up to an annealing temperature of 500 °C, and these values gradually decreased above the annealing temperature of 600 °C, while a sharp reduction in the percentage reduction in area (RA) occurred at the annealing temperatures of 600 and 700 °C due to Cr2N precipitation along the grain and twin boundaries. The ratio of 0.2% offset yield strength to ultimate tensile strength (0.2% YS/UTS) remained constant until matrix recovery took place; however, once recrystallization occurred, the ratio decreased significantly. Furthermore, the variation in the morphology of Cr2N along the grain boundaries in the annealing temperature range from 600 to 800 °C influenced the intergranular fracture morphology, resulting in a transition from dimple to ledge and back to dimple.

Greenly building strong interactions between epoxy and carbon fiber fabric via vapor assisted ozone

AbstractTo enhance the performance of carbon fiber reinforced polymer (CFRP), it is crucial to establish robust interactions between epoxy and carbon fiber fabric (CFF). Herein, CFF was treated by an optimized H2O2/H2O/O3 oxidation method. The chemical and physical properties of the treated CFFs were meticulously characterized. For comparison, CFF, O3 treated CFF, and H2O/O3 treated CFFs were also examined. It was found that H2O2/H2O/O3 oxidized CFF more effectively than either O3 or H2O/O3. Reactive O groups were extensively grafted onto the surface of the H2O2/H2O/O3 oxidized CFF, leading to an increase in surface energy. Additionally, numerous defects were introduced on the surface of the H2O2/H2O/O3 oxidized CFF, significantly enhancing its surface roughness. Consequently, the interlaminar shear strength of H2O2/H2O/O3 oxidized CFF reinforced epoxy composite reached 63.31 ± 2.50 MPa, which is 43.3% higher than that of CFF reinforced epoxy composite. The fracture surface morphology and differential scanning calorimetry studies confirmed the presence of strong interfacial chemical interactions, while the increased surface roughness ensured robust interfacial physical interactions. Based on these findings, the mechanisms of the H2O2/H2O/O3 oxidized CFF reinforcing epoxy were proposed. The present work aims to give out some ideas for the fabrication of green and advanced CFRP.Highlights CFF was effectively oxidized by an optimized H2O2/H2O/O3 method eco‐friendly. Improved the interlaminar shear strength of the epoxy composite by 43.3%. Both the strong interfacial chemical and physical interactions were confirmed. The reinforcing mechanism is attributed to the robust interactions.

Study on the influence of pore water pressure on shear mechanical properties and fracture surface morphology of sandstone

To further investigate the weakening effect of pore water pressure on intact rock mechanics properties and characteristics of fracture surface after failure, direct shear tests of sandstone were conducted under different pore pressure. A 3D scanner was employed to digitize the morphology of the post-shear fracture surface. The variogram function was applied to quantify the anisotropic characteristics of post-shear fracture surface. The relationship between deformation during shear failure of intact rock and quantitative parameters of fracture surface after shear failure was initially established. It can be found that amplitudes of the sinusoidal surface determine the maximum value of variogram, and period affect lag distance that reach the maximum value of variogram. Test results revealed that the increase of pore pressure has obvious weakening effect on shear strength and deformation of rock. Moreover, the increase of pore pressure makes the shear fracture surface flatter. It can be obtained that both Sillmax and Rangemax are positively related to shear strain, but negatively related to normal strain.

Dynamic fracture properties and criterion of cyclic freeze-thaw treated granite subjected to mixed-mode loading

Rock masses in high-elevation or cold regions are vulnerable to the combined effects of freeze-thaw (F-T) weathering and dynamic mixed-mode loading, posing a serious threaten to the safety and stability of geotechnical engineering. In this study, a series of dynamic fracture tests were conducted on notched semi-circular bend (NSCB) granite specimens subjected to different mixed-mode loading and F-T cycles using a split Hopkinson pressure bar (SHPB) test system. The effects of F-T treatment and dynamic mixed-mode loading on the fracture properties of granite, including effective fracture toughness, progressive fracture process, and macroscopic morphology of fracture surface, were comprehensively revealed. The experimental results suggest that the dynamic effective fracture toughness of NSCB specimens is dependent on the loading rate, particularly when the mode I loading is dominant. Additionally, the fracture toughness decreases as the number of F-T cycles increases, with an inflection point at 30 F-T cycles. All granite specimens subjected to mixed-mode loading exhibit a curved fracture path, with faster crack propagation speed and more fine cracks in specimens exposed to higher F-T cycles. Macroscopic morphology of fracture surface obtained using three-dimensional (3D) scanning indicates that the fractal dimension of the fracture surface increases with increasing F-T cycles, and the increment is more pronounced for specimens subjected to a higher mode II loading component. Moreover, this study compared the fracture resistance of F-T treated granite subjected to dynamic mixed loading using the maximum tangential stress (MTS) criterion and the generalized maximum tangential stress-based semi-analytical (SA-GMTS) criterion. Compared with the MTS criterion, the SA-GMTS criterion shows a more reasonable consistency with the experimental results, with a root mean square error within ±7%.

Synergistic enhancement in mechanical properties of graphene/MWCNT reinforced Polyaryletherketone – carbon fiber multi-scale composites: Experimental studies and finite element analysis

This investigation focuses on the synergistic performance improvement in graphene/MWCNT reinforced Polyaryletherketone (PAEK) - carbon fiber (CF) multi-scale composites. FTIR revealed the chemical interactions while HRTEM, XRD and 3D X-ray microscopy gave insight into nanofiller dispersion and microstructural features. The functional groups on nanofillers along with structural features integrated various components of the multi-scale composites by formation of graphene/MWCNT/CF complex network that provided larger interfacial area, bridging effect and physico-chemical interaction with PAEK while restricting its segmental mobility. Multi-scale composites displayed significantly improved strength, fracture toughness, interlaminar shear strength, glass transition temperature and tribological performance. Under dynamic load, graphene/MWCNT reinforcement of matrix and CF synergistically increases the storage modulus and energy absorption characteristics. Wear and fracture surface morphology of nano and multi-scale composites showed ductile failure confirming interfacial adhesion. The failure behavior in experimental studies was supported by Abaqus/Explicit-based FEM models of fracture toughness response. This work provides a promising avenue to develop next generation high performance thermoplastic composites for structural applications.

Digital Fracture Surface Morphology and Statistical Characteristics of Granite Brazilian Tests after Non-Steady-State Thermal Disturbance

With the widespread advent of digital technologies, traditional perspectives in rock mechanics research are poised for further expansion. This paper presents a Brazilian test conducted on granite after non-steady-state thermal disturbance at 25 °C, 200 °C, 400 °C, and 600 °C, with detailed documentation of the damage process and failure response using an acoustic emission (AE) apparatus and a digital image correlation (DIC) system. Subsequently, utilizing point cloud data captured by a three-dimensional (3D) laser scanning system, a digital reconstruction of the failed specimen’s fracture surface was accomplished. The 3D fractal characteristics and roughness response of the digitized fracture surface were studied using the box-counting method and least squares approach. Furthermore, texture information of the digitized fracture surface was calculated using the Gray Level Co-occurrence Matrix (GLCM), and statistical characteristics describing the elevation distribution were analyzed. The results elucidate the influence of thermal disturbance temperature on the mechanical parameters of the specimen, acoustic emission behavior, surface strain field evolution, and digital fracture morphology characteristics. The findings indicate a non-linear degradation effect of temperature on the specimen’s tensile strength, with a reduction reaching 80.95% at 600 °C, where acoustic emission activity also peaked. The rising thermal disturbance temperature inhibited the crack initiation load at the specimen’s center but expanded the high-strain concentration areas and the growth rate of horizontal displacement. Additionally, varying degrees of linear or non-linear relationships were discovered between thermal disturbance temperature and the 3D fractal dimension of the fracture surface, average roughness (Ra), peak roughness (Rz), and root mean square roughness (Rq), confirming the potential of Rsm in predicting the 3D fractal dimension of Brazilian test fracture surfaces. The study of the GLCM of the digitized 3D fracture surface demonstrated a high dependency of its four second-order statistical measures on thermal disturbance temperature. Finally, the statistical parameters of the fracture surface’s elevation values showed a significant non-linear relationship with thermal disturbance temperature, with a critical temperature point likely existing between 400 and 600 °C that could precipitate a sudden change in the fracture surface’s elevation characteristics.

Insights into thermomechanical fatigue behavior of nitrogen alloyed 316LN stainless steel under various temperature cycling ranges

Thermomechanical fatigue (TMF) failure has become one of the most important life-limiting factors of components exposure to the high temperature in the fourth-generation sodium-cooled fast reactor (SFR) nuclear power plant. Therefore, TMF tests at different temperature cycling ranges are performed to study the cyclic deformation behavior and damage mechanism of a nitrogen alloyed 316LN stainless steel. Moreover, the isothermal fatigue (IF) tests at the maximum temperature of TMF cycling are conducted for comparison. The cyclic hardening and softening response are analyzed, taking into account the phenomenon of dynamic strain aging which occurs at the temperature range of 350 °C–650 °C. Furthermore, the critical strain corresponding to the occurrence of serrated stress flow in engineering stress-strain curves keeps decreasing from 28.94% at 350 °C to 0.09% at 650 °C. The distribution of plastic deformation and the degree of strain localization are evaluated by the characterization results of kernel average misorientation map, high/low angle grain boundary map and dislocation configuration. The dominant damage mechanism and its corresponding cracking behavior in both IF and TMF tests are analyzed based on the observation of fracture surface morphology. In addition, the sequence order of fatigue life is determined as IF < IP-TMF < OP-TMF. Moreover, the maximum difference of fatigue life between IF test and TMF test occurs at the temperature range of 400 °C–600 °C, in which the IP and OP life is about 2.91 and 3.65 times larger than the IF life. The results in this work provide reliable data support and theoretical guidance for the fatigue design of high-temperature components in SFR.

Effects of temperature and strain amplitude on low-cycle fatigue behavior of 12Cr13 martensitic stainless steel

12Cr13 martensitic stainless steel has been selected as the structural material for steam turbine blade which is frequently subjected to low-cycle fatigue (LCF) damage. The study involved conducting low-cycle fatigue (LCF) tests under strain control at various temperatures (25 °C, 250 °C, 350 °C, 450 °C) and strain amplitudes (±0.3 %, ±0.4 %, ±0.5 %, ±0.6 %). The cyclic deformation behavior, primarily indicating cyclic stress response and the Massing effect is thoroughly analyzed based on the characterization of dislocation microstructure and electron backscatter diffraction maps. The mechanism of crack initiation and the propagation behavior are discussed based on the SEM observations of microcracks on the specimen surface and the fracture surface morphology. The influence of temperature and strain amplitude on fatigue life behavior is determined, and the underlying mechanisms are revealed. Moreover, the life prediction is performed by using the classical Basquin-Coffin-Manson model at ambient temperature.

Fracture surface morphology effect on radial seepage flow in a horizontal single granite fracture

Fracture surface morphology effect on radial seepage flow in a horizontal single granite fracture

Waste chicken feather biofiller reinforced bioepoxy resin based biocomposites — A waste to wealth experimental approach

Utilizing poultry wastes, particularly chicken feathers, in biopolymer composites is seen as an important aspect in lowering the environmental pollution and paving a new path to sustainability. The main objective of this experimental study is to develop polymer composites reinforced with waste chicken feather fillers and evaluate their physical, mechanical, and thermal characteristics. The composites were fabricated through an open mold casting process using bio epoxy (SR-33 Greenpoxy) as the matrix and chicken feather filler as a reinforcement in three distinct weight fractions (2.5, 5, and 7.5 wt%). To evaluate the effects of filler content on the mechanical properties of the fabricated bio-epoxy composites, they were subjected to tensile, flexural, impact, and hardness tests. The findings from the experimental studies demonstrated that the composites containing 2.5 wt% of chicken feather filler had improved mechanical properties, thermal stability, and crystallization behaviour. The thermal attributes of samples included a greater melting point, lower recrystallization temperature, higher glass transition temperature, and quicker crystallization rates. The Scanning Electron Microscope analysis of the fracture surface morphology of the biocomposites showed a better interfacial adhesion between the filler and matrix. It could be concluded from the results that the waste chicken feather can be used as potential filler reinforcements for begetting natural composites for various low- and medium-density structural and non-structural applications.

Experiment study on shear behavior and properties of granite fractures under real-time high-temperature conditions

Direct shear tests were conducted on granite fractures with similar joint roughness coefficients under real-time high temperatures (up to 400 °C) and constant normal stiffness conditions. In this study, the shearing process was monitored via acoustic emission, and fracture surface morphology was measured with three-dimensional laser scanning. With increasing temperature, peak and residual shear strengths, peak friction coefficient, and maximum normal dilation became higher. In contrast, peak normal displacement and peak shear displacement decreased. The apparent cohesion and internal friction angle exhibited opposite trends as temperature increased, primarily due to competition between thermal hardening and thermal cracking. The elastic strain energy of stick-slip events increased with temperature. From 100 °C to 400 °C, the degradation of fracture roughness and the volume of sheared-off asperities grew. Real-time temperature influences shear properties and is mainly attributed to physical and geometrical changes. Acoustic emission parameters, including count, energy, and hit, show segmented variation during fracture shearing. Based on parameter analyses of the average frequency and rise angle values, during the shearing process, the proportion of shear cracks at each stage varied with temperature. Shear failure was the predominant failure mode. Results from this study provide insight into the shear behavior of granite fractures under real-time high temperatures.

Additive Manufacturing of Halochromic Polylactic Acid (PLA)

With increasing concerns regarding plastic waste and pollution, researchers have been looking to develop advanced materials from biodegradable plastics. This study features a halochromic biodegradable polymer produced using additive manufacturing. The purpose of this research is to fabricate halochromic polylactic acid (PLA) filaments and assess its halochromic behaviour, mechanical and chemical properties of the 3D printed PLA specimens. PLA/polyethylene glycol (PEG)/bromocresol purple (BCP) compound was prepared and added in extrusion to produce a 3D printing filament. Dumbbell-shaped and rectangular specimens were fabricated from the filament through 3D printing. The halochromic responsiveness and colour reversibility were tested by exposing the samples to liquid and vaporized hydrochloric acid (strong acid), acetic acid (weak acid) and ammonia (strong alkali). The tensile properties, fracture surface morphology and chemical species of the specimens were tested and analyzed through tensile test, scanning electron microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy. The halochromic responsiveness shows obvious colour changes from yellow to blue when exposed to strong alkali. The tensile strength and modulus were found to be higher in comparison to plasticized PLA but the elongation at break was lower. SEM morphology show brittle fracture characteristics in the printed specimens. Overall, the 3D printed halochromic PLA specimens show promising results and have proven their functionality as pH sensors which offers wide applications in many industries such as medical, environmental and packaging.

Numerical investigation of heat transfer characteristics of supercritical CO2 and water flow in 2D self-affine rough fractures

In recent years, efforts to maximize natural energy utilization have focused on harnessing energy from hot dry rocks (HDR) using supercritical carbon dioxide (SCCO2) or water as the heat transfer fluid. This study aims to enhance comprehension and evaluate the heat extraction performance of enhanced geothermal systems (EGS) by exploring the influence of various inlet velocities and fracture widths on the flow and heat transfer of SCCO2 and water within a rough single fracture in granite. This study utilized a 2D self-affine fractal function to create a rough-fractured rock with fractal properties in a φ50 × 100 mm granite sample. Investigating under 8 MPa conditions, we employed the thermophysical properties of SCCO2 and water to analyze the flow and heat transfer characteristics within the rough rock fractures. The results indicate the following: (1) Higher inlet velocities and wider fracture widths result in a broader temperature reduction range within the surrounding rock matrix for both SCCO2 and water. (2) Increasing the inlet flow velocity of SCCO2 and water leads to wider fracture widths, resulting in lower temperatures at the outlet end of the fracture. As the inlet flow velocity increases from 0.01 m/s to 0.04 m/s, the rate of temperature increase at the outlet can reach up to 19.8 % compared to water. (3) SCCO2, unlike water, exhibits significant reverse vortices at locations where the fracture surface morphology experiences substantial fluctuations. This behavior may be an indirect consequence of SCCO2’s higher velocity, with the direct cause being SCCO2’s lower viscosity and density than water. (4) Among the four conventional fluid thermodynamic parameters, specific heat capacity has the most significant impact on total energy flux rate (TEFR).