Evolution Of Temperature Field Research Articles

A Refined Method for Altimetry SSH Data Fusion to Enhance the Characterization of Kuroshio Extension: A Case Study

Abstract High-quality merged altimetry sea level products have been instrumental in analyzing oceanic dynamics, spanning global and regional sea level trends, and capturing interannual signals, but effectively characterizing mesoscale features remains a persistent issue. The essence of addressing this challenge lies in the selection of highly correlated data sources for fusion, within the confines of limited discrete observations from sea surface altimeters. To tackle this challenge, we propose a refined method focused on reducing the suboptimal interpolation window size and optimizing the mapping process, particularly emphasizing the enhancement of Kuroshio Extension (KE) characterization. By scrutinizing the spatial and temporal evolution of Sea Surface Temperature (SST) fields, we have devised a modified strategy for selecting altimetry along-track data. This strategic approach facilitates the acquisition of more precise observations on a finer time scale, thereby circumventing the inclusion of altimetry observations with low correlation. To validate the efficacy of this approach, we performed a case study of Sea Surface Height (SSH) data fusion in the KE region. As a result, the portrayal of KE intricacies, encompassing its axis and meandering, has markedly improved in the refined SSH gridded maps. Comparative analysis against drifter observations underscores the efficacy of the refined method. Velocity biases have been substantially reduced from −0.21 m/s to 0.05 m/s, while the correlation coefficient has surged from 0.64 to 0.90. Concurrently, the root mean square error has plummeted from 0.42 m/s to 0.21 m/s. These improvements signify significant strides toward more accurate and reliable characterizations of oceanic mesoscale features, particularly evident in the nuanced depiction of the KE.

Effect of double-layer formwork curing on the early temperature field and properties of precast concrete components in environments with large diurnal temperature variations

An efficient double-layer formwork curing method using an “inner supporting formwork + outer insulation formwork” was proposed in this study to address the early cracking of precast concrete components in high altitude regions. Steel and plywood formwork were designed as inner support formwork, while polystyrene (PS) and polyurethane (PU) were used as outer insulation formwork. Indoor experiments and two finite element methods (The complete simulation method focuses on computational accuracy, and the equivalent simulation method emphasizes computational efficiency) were employed to analyze the evolution of the concrete temperature field under different double-layer formwork curing methods throughout the curing period, combined with compressive strength and pore structures testing. The results show that steel + 5-mm-thick PU insulation formwork curing method can significantly mitigate the impact of large diurnal temperature variations on the internal temperature of concrete. Unlike traditional steam-curing, this method does not deteriorate the pore structure or compressive strength of the concrete. This study is of great significance in addressing the problem of early cracking of precast concrete components exposed to large diurnal temperature vriations in high altitude regions.

Experimental investigation on enhanced oil recovery of heavy oil via cyclic supercritical water stimulation

With the gradual depletion of conventional oil resources, the exploitation of heavy oil is essential to alleviate the energy crisis, as fossil energy remains predominant in global energy supply. The feasibility of cyclic supercritical water (SCW) stimulation is confirmed by oil field tests, while the enhanced oil recovery (EOR) mechanisms and the dynamic characteristics of displacement are still unclear owing to the scarceness of relevant studies. In this study, an experimental system with a design temperature up to 450 °C and pressure up to 30 MPa was developed to simulate the cyclic SCW stimulation process. A customized two-dimensional sand pack core with equitable temperature measuring arrangement can monitor the dynamic evolution of temperature field. The results of the core experiments indicated that the injection of SCW obviously enhances oil production, with the ultimate oil recovery factor up to 75.91%, which was 18.85% higher than that of steam. The formation and expansion of the SCW gravity override was found to be one of the mechanisms for boosting oil production. At the end, the swept volume coefficient of SCW was enlarged from 5.39% to 10.53%, which was 2.99 times that of steam. The large expansion of the gravity override zone of SCW in the vertical and radial directions changes the heat and mass transfer law, raises the core temperature, and expands the swept volume. Further, the condensation of supercritical water in the soak stage caused pressure difference (up to 11.12 MPa) near the well driving distant heavy oil to flow towards. These findings have the potential to deepen the understanding of the EOR mechanisms of SCW stimulation and provide theoretical guidance for improving oil production in oilfields.

Ultra-Short Pulses Laser Heating of Dielectrics: A Semi-Classical Analytical Model.

Femtosecond laser pulses are currently regarded as an emerging and promising tool for processing wide bandgap dielectric materials across a variety of high-end applications, although the associated physical phenomena are not yet fully understood. To address these challenges, we propose an original, fully analytical model combined with Two Temperatures Model (TTM) formalism. The model is applied to describe the interaction of fs laser pulses with a typical dielectric target (e.g., Sapphire). It describes the heating of dielectrics, such as Sapphire, under irradiation by fs laser pulses in the range of (1012-1014) W/cm2. The proposed formalism was implemented to calculate the free electron density, while numerical simulations of temperature field evolution within the dielectrics were conducted using the TTM. Mathematical models have rarely been used to solve the TTM in the context of laser-dielectric interactions. Unlike the TTM applied to metals, which requires solving two heat equations, for dielectrics the free electron density must first be determined. We propose an analytical model to solve the TTM equations using this parameter. A new simulation model was developed, combining the equations for non-equilibrium electron density determination with the TTM equations. Our analyses revealed the non-linear nature of the physical phenomena involved and the inapplicability of the Beer-Lambert law for fs laser pulse interactions with dielectric targets at incident laser fluences ranging from 6 to 20 J/cm2.

Numerical simulation of the coupled thermal-hydro-mechanical fields for evaluating CO2 geo-sequestration storage in deep saline aquifers of Hainan Fushan Sag, China

Geo-sequestration storage of CO2 in saline aquifers is an important technological option to reduce carbon emissions in China in the future. The theory of geo-sequestration storage of CO2 in saline aquifers involves complex physical operations and chemical phenomena among reservoir stress, seepage, and temperature fields, and the numerical simulation models coupling thermal-hydro-mechanical (THM) fields are widely applied to analyze the evolution of multiphysical processes in CO2 reservoirs. Based on the geo-sequestration storage project of saline aquifer CO2 in Fushan Sag, Hainan Province, under the premise of considering the change of permeability and porosity after the mineralization of CO2 in the rock reservoirs, this study simulates the evolution of temperature, stress, and seepage fields during the sequestration process of saline aquifer Continuous CO2 injection wells clarifies the range of influence of the temperature field, seepage field, and the boundary of its stress field of saline aquifer Continuous CO2 injection wells in different sequestration periods. It reveals the influence mechanism of the fault structure on the reservoir CO2 sequestration pressure and capacity, and evaluates and estimates the CO2 injection storage capacity of Fu 1# well in Fushan Sag and on this basis. The THM numerical simulation model proposed in this study plays a crucial role in guiding theoretical evaluations of the CO2 geo-sequestration potential in saline aquifers and determining its technical parameters, thereby offering significant value for engineering applications.

Simulation and experimental investigation of grain structure, residual stress,γ′ phases in single crystal blade

Ni-based superalloy turbine blades have been required components in contemporary aero-engine. Knowing the solidification behavior, residual stress at grain defects, and microstructure of directionally solidified turbine blades is a required condition to improve the service performance of directionally solidified turbine blades. Firstly, the temperature field evolution of the blade under the withdrawal rate of 3 mm/min was studied. The deviations in temperature distribution in the high-rate solidification (HRS) procedure, particularly near the platform, can lead to transformations in the mushy zone, potentially resulting in solidification defects. Secondly, the grain growth of hollow turbine blades was calculated using the cellular automaton-finite factor method. The simulated grain framework was essentially consistent with experimental results. A method of process bar addition based on physical field distribution is also proposed. This method involves designing a combination of one Y-shaped and two I-shaped rods to decrease the cooling rate of blade edges and eliminate stray grains (SG). Then, the residual stress distribution at the locations of stray grains and low-angle grain boundaries (LAGBs) was analyzed before and after the addition of process bars. Finally, discussions were held regarding the distribution of γ′ phases in grain defects and blades.

Numerical simulation of molten pool flow behavior in ultrasonic vibration-assisted gas tungsten arc welding of low-alloy high-strength steel

The beneficial effects of ultrasonic vibration-assisted arc welding on the performance of welded joints have been experimentally confirmed. However, the mechanism of the influence of ultrasonic vibration on the temperature and flow fields of the welding pool is still not clear, which also limits further application prospects of this technology. The present study established a three-dimensional molten pool model for ultrasonic vibration-assisted gas tungsten arc (UV-GTA) welding of low-alloy high-strength steel, considering free deformation of the molten pool surface and different ultrasonic vibration amplitudes. The temperature field evolution and the molten pool flow behavior under various ultrasonic vibration amplitudes were systematically analyzed. Compared with GTA welding, the ultrasonic vibration in UV-GTA welding enhanced uniformity of the temperature distribution in molten pool. Moreover, the larger the ultrasonic amplitude in UV-GTA welding, the smaller the depth of the molten pool and the time required for the molten pool to reach a quasi-steady state, but the larger the maximum flow rate at the surface as well as at the center of the molten pool. At an ultrasonic vibration amplitude of 40 µm, the molten pool depth in UV-GTA welding decreased by 34.8 % compared with GTA molten pool depth. The time for this UV-GTA molten pool to reach a quasi-steady state was just 0.57 s, and the maximum velocity at its center increased by 88.1 % over that of the GTA molten pool. Comparative analysis of the UV-GTA molten pool and the GTA molten pool revealed a shorter circulating flow field on the upper surface and periodic variations in the internal flow field motion. The simulation outcomes closely align with the experimental findings, confirming both the validity of the model and the accuracy of the pertinent conclusions. This research may lay a solid theoretical foundation for further systematic exploration of the wider application prospects of ultrasonic vibration-assisted arc welding.

Numerical simulation of thermal and stress fields for multilayer and multi-pass weaving WAAM of magnesium alloy

Purpose A 3D finite element (FE) model based on the double ellipsoidal heat source was developed to investigate the evolution of temperature and stress fields during the multilayer and multi-pass wire and arc additive manufacturing (WAAM) process. This paper aims to investigate the evolution of temperature and stress fields during the multilayer and multi-pass wire and arc additive manufacturing (WAAM) process by developing a 3D finite element (FE) model based on the double ellipsoidal heat source. Design/methodology/approach Experimental thermal cycle curves and residual stresses were obtained by thermocouples and X-ray diffraction, respectively. The validity of the model was verified by the corresponding experimental results. Findings The deposition process of the upper pass led to the partial remelting of the lower deposited pass. The thermal process of the current-deposited pass alleviated the stress concentration in the previous-formed passes. A more uniform temperature distribution could be obtained by using the reciprocating deposition path. Compared to the reciprocating deposition path, the peak values of the transverse and longitudinal tensile residual stresses of the deposited sample under the unidirectional deposition path were reduced by 15 MPa and increased by 13 MPa, respectively. The heat conduction in the deposited passes could be improved by extending the inter-pass cooling time appropriately. With an increase in the inter-pass cooling time, the longitudinal residual stress in the middle region of sample along longitudinal and transverse directions showed increase and decrease–increase trends, respectively, while the transverse residual stress exhibited decrease trend. Originality/value This study enhances the understanding of temperature and stress fields evolution during the multilayer and multi-pass cold metal transfer-WAAM processes of magnesium alloy and provides the reference for parameter optimization.

In Situ Conductive Heating for Thermal Desorption of Volatile Organic-Contaminated Soil Based on Solar Energy

A novel conductive heating method using solar energy for soil remediation was introduced in this work. Contaminated industrial heritage sites will affect the sustainable development of the local ecological environment and the surrounding air environment, and frequent exposure will have a negative impact on human health. Soil thermal desorption is an effective means to repair contaminated soil, but thermal desorption is accompanied by a large amount of energy consumption and secondary pollution. Therefore, a trough solar heat collection desorption system (TSHCDS) is proposed, which is applied to soil thermal desorption technology. The effects of different water inlet temperature, water inlet velocity and soil porosity on the evolution of soil temperature field were discussed. The temperature field of contaminated soil can be numerically simulated, and a small experimental platform is built to verify the accuracy of the numerical model for simulation research. It is concluded that the heating effect is the best when the water entry temperature is the highest, at 70 °C, and the temperature of test point 4 is increased by 50.71% and 1.42%, respectively. When the inlet water flow rate is increased from 0.1 m/s to 0.2 m/s, the heating effect is significantly improved; when the inlet water flow rate is increased from 0.5 m/s to 1.5 m/s, the heating effect is not significantly improved. Therefore, when the flow rate is greater than a certain value, the heating effect is not significantly improved. The simulation analysis of soil with different porosity shows that larger porosity will affect the thermal diffusivity, which will make the heat transfer effect worse and reduce the heating effect. The effects of soil temperature distribution on the removal of petroleum hydrocarbon C6–C9 and trichloroethylene (TCE) were studied. The results showed that in the thermal desorption process of petroleum hydrocarbon C6–C9-contaminated soil, the removal rate of pollutants increased significantly when the average soil temperature reached 80 °C. In the thermal desorption of trichloroethylene-contaminated soil, when the thermal desorption begins, the soil temperature rises rapidly and reaches the target temperature, and a large number of pollutants are removed. At the end of thermal desorption, the removal of both types of pollutants reached the target repair value. This study provides a new feasible method for soil thermal desorption.

Study on the Influence of Laser Power on the Heat–Flow Multi-Field Coupling of Laser Cladding Incoloy 926 on Stainless Steel Surface

In order to explore the influence of laser power on the evolution of molten pool and convective heat transfer of laser cladding Incoloy 926 on stainless steel surface, a three-dimensional thermal fluid multi-field coupled laser cladding numerical model was established in this paper. The variation of latent heat during solid-liquid phase transformation was treated by apparent heat capacity method. The change in the gas–liquid interface was tracked using the mesh growth method in real time. The instantaneous evolution of temperature field and velocity flow field of laser cladding Incoloy 926 on a stainless steel surface under different laser power was discussed. The solidification characteristic parameters of the cladding layer were calculated based on the temperature-time variation curves at different nodes. The mechanism of the impact of laser power on the microstructure of the cladding layer was revealed. The experiment of laser cladding Incoloy 926 on 316L surface was carried out under different laser power. Combined with the numerical simulation results, the effects of laser power on the geometrical morphology, microstructure and element distribution of the cladding layer were compared and analyzed. The results show that with the increase in laser power, the peak temperature and flow velocity of the molten pool surface both increase significantly. The thermal influence of the molten pool center on the edge is enhanced. The temperature gradient, solidification rate, and cooling rate increased gradually. The microstructure parameters (G/R) are relatively small when the laser power is 1000 W. In the experimental range, the dilution rate and wetting angle of the cladding layer both increase with the increase in laser power. When the laser power is 1000 W, the alloying elements of the cladding layer are more evenly distributed and the microstructure is finer. The experimental results are in good agreement with the simulation results.

Analysis of thermal production effect of multi-horizontal U-shaped well

The multi-horizontal section hot dry rock (HDR) heat extraction system is proposed for efficient deep geothermal resources mining in this study. The thermal-hydraulic numerical model of the multi-horizontal section geothermal exploitation system is set up, the space-time evolution of temperature field is analyzed. The sensitivity factors including completion schemes, horizontal well diameter, quantity of horizontal sections and spacing of horizontal sections are investigated. The simulation results show that the production temperature and heating power of the multi-horizontal HDR production system decrease with the development of mining, and the decreasing speed gradually slows down. The open hole completion can be preferred when the formation conditions permit. The variation of horizontal well diameter has little effect on heat production when other conditions remain unchanged. The quantity of horizontal sections to be 3 or 4 for better heat extraction performance under the spacing of horizontal section remains 300m and the spacing of the horizontal section to be 150m is recommended within the scoped of this study. The results of this study can provide guidance for HDR mining research.

Exploring β12-Borophene magnetic response through Monte Carlo simulations

ABSTRACT In this work, we used Monte Carlo simulations under the Metropolis algorithm to study the magnetic characteristics of β12-Borophene. We investigated the effects of temperature, coupling interaction parameters, and external magnetic fields on changes in the magnetic response. We investigated the blocking temperature and coercive field evolution under the given conditions. The β12-Borophene under investigation exhibits a remarkable magnetic response at low temperatures, suggesting possible uses in a range of low-temperature technologies.

Twenty Years of Thermal Infrared Observations (2004–2024) at Campi Flegrei Caldera (Italy) by the Permanent Surveillance Ground Network of INGV-Osservatorio Vesuviano

Thermal infrared (TIR) time series images acquired by ground, proximal TIR stations provide valuable data to study evolution of surface temperature fields of diffuse degassing volcanic areas. This paper presents data processing results related to TIR images acquired since 2004 by six ground stations in the permanent thermal infrared surveillance network at Campi Flegrei (TIRNet) set up by INGV-Osservatorio Vesuviano. These results are reported as surface temperature and heat flux time series. The processing methodologies, also discussed in this paper, allow for presentation of the raw TIR image data in a more comprehensible form, suitable for comparisons with other geophysical parameters. A preliminary comparison between different trends in the surface temperature and heat flux values recorded by the TIRNet stations provides evidence of peculiar changes corresponding to periods of intense seismicity at the Campi Flegrei caldera. During periods characterized by modest seismicity, no remarkable evidence of common temperature variations was recorded by the different TIRNet stations. Conversely, almost all the TIRNet stations exhibited common temperature variations, even on a small scale, during periods of significant seismic activity. The comparison between the seismicity and the variations in the surface temperature and heat flux trends suggests an increase in efficiency of heat transfer between the magmatic system and the surface when an increase in seismic activity was registered. This evidence recommends a deeper, multidisciplinary study of this correlation to improve understanding of the volcanic processes affecting the Campi Flegrei caldera.

Experimental Study and Neural Network Predictions of Early-Age Behavior of Microexpansion Concrete in Large-Diameter Steel Tube Columns

The improved mechanical performance of concrete-filled steel tube (CFST) components has led to their widespread application in megastructures. Therein, CFST hybrid arch bridge has become an optimal selection of large span bridges. Nonetheless, for massive concrete poured in CFST members with large diameter, the thermal cracking and sustained rising temperature caused by early hydration heat of core concrete are urgently required to be studied. The two large-diameter CFST columns in this work, each having a diameter of 2.1 m, had their temperature and strain fields recorded in-situ. An existing CFST arch bridge served as the model for the two CFST columns’ design. Additionally, early-age characteristics of several scaled CFST columns with varying diameters were documented. A multi-field finite element (FE) model that combines linked chemical (hydration), heat, and mechanical fields is suggested in order to properly characterize the evolutions of temperature and strain fields. The model is validated by comparing the in-situ measurements with the numerical results. Finally, to investigate the affect factors on the hydration temperature of core concrete in CFST columns, early-age hydration behaviors of CFST columns was simulated using the validated FE models input parameters as water to cement ratio (w/c), cement dosage, heat release of cement and diameter of CFST columns. Based on the numerical results under the input parameters mentioned, the LSTM neural network was constructed, and the hydration temperature variances computed by FE models were selected as the input dataset. Afterwards, the temperature variance of core concrete of CFST columns was predicted using the established LSTM network. It is discovered that the LSTM neural network that was previously constructed was able to predict the peak temperature of CFST columns as well as the hydration temperature of CFST specimens with respect to time.

Vibration-assisted cutting of thermoplastic CF/PEEK: understanding the cutting mechanism and temperature field evolution

Vibration-assisted cutting of thermoplastic CF/PEEK: understanding the cutting mechanism and temperature field evolution

Dynamic evolution of temperature field, flow field, and solidification behavior during multilayer multitrack laser cladding

During multilayer multitrack laser cladding, secondary melting and solidification in the interlayer lap zone have a significant impact on the mechanical properties of cladding coatings. However, mathematical modeling of the melt flow and solidification behavior of multilayer, multitrack laser cladding interlayer lap zones is lacking. In this paper, a 3D finite element model was established to investigate the mass and heat transfer processes in both lap and non-lap zones during the laser cladding of multilayer multitrack Fe-Cr-based alloys on 45# steel surface. A dynamic grid is used to track the free surface of the melt pool, while the enthalpy method is used to simulate the solid-liquid phase transition. The change in thermophysical properties with temperature, as well as the change in laser energy and alloy powder flow density in the lap zone, were taken into consideration. The influence of the number of cladding layers on the heat and mass transfer in the molten pool, remelting, and solidification in the lap zone was investigated, along with its intrinsic mechanism. The results show that the model can accurately predict the size and microstructural change law of coating layers, including the grain size of the lap region between layers. The melt pool temperature and grain size increase with the number of cladding layers, while the convection and cooling velocities decrease. In addition, the grain size in the lap zone of the cladding is larger than that in the nearby non-lap zone. Using solidification parameters extracted from the solidification front of the molten pool, changes in grain size and morphology were predicted for both the interlayer lap and non-lap zones. The numerical calculation results were consistent with the experimental measurements.

Research progress on temperature field evolution of hot reservoirs under low-temperature tailwater reinjection

Research progress on temperature field evolution of hot reservoirs under low-temperature tailwater reinjection

Contrastive Analysis of Interferometric Techniques for Small Channel Temperature Measurements

This research employs a state-of-the-art digital interferometric technique to investigate the temperature distribution within a confined rectangular channel, with a hydraulic diameter of 3 mm. The experimental setup incorporates an optical glass channel, with nanofluids (Aluminium oxide) as the test fluid at 0.001% volume concentration. To induce controlled heating, a heater filament is strategically placed along the bottom wall of the channel. Simultaneously, a T-type thermocouple is carefully placed to measure the temperature along the upper wall. Two distinct interferometric methods, namely the Michelson interferometer and the Mach-Zehnder interferometer, are employed to capture the complex details of fringes resulting from the evolving temperature field within the test section. A high-resolution CCD camera is employed to capture these fringes, and sophisticated digital image processing techniques are subsequently applied for in-depth fringe analysis. The culmination of these efforts results in the origin of a comprehensive localized temperature distribution map within the small-sized channel. The obtained temperature profiles are meticulously compared, providing valuable insights into the effectiveness and reliability of the Michelson and Mach-Zehnder interferometric techniques in this specific experimental context. This detailed comparative analysis contributes to the broader understanding of interferometric methods for temperature measurements in confined fluidic systems.

Computational analysis of thermal cycling phenomena during multilayer laser powder bed fusion process for Ti6Al4V

During laser powder bed fusion (LPBF) process, single tracks overlap to form layers and layers merge to form the complete 3D object. Because of this, a recurring temperature rise and fall happens, which is called thermal cycling phenomenon. It affects the microstructure and mechanical properties of the manufactured component via multiple reheating (and remelting) cycles, resulting in an intrinsic aging type heat treatment process that invokes an additional anisotropy along the build direction. To date, this phenomenon has been rarely studied due to the computational resource constraints and difficulties in experimental temperature measurement. Hence, in this study, a computationally efficient thermal model has been developed and applied to study the multilayer LPBF process for Ti6Al4V. The model was validated against the single track single layer experimental data and then used to simulate multilayer LPBF till a height of 3 layers to study the temperature field evolution and thermal cycling phenomenon. The average temperature of the computational domain is plotted against time to show the origin of intrinsic heat treatment. It is observed that while with each next layer the temperature rises, the maximum temperature value remains constant due to material evaporation taking place. The results suggest that thermal buildup also happens in the process as the average temperature of the computational domain as well as the melt pool volume increases with each layer.

On the chip formation mechanism when cutting Ti6Al4V with localised supply of liquid nitrogen

In cryogenic machining, employing internal supply cooling through the tool not only diminishes tool wear and enhances workpiece machining quality but also offers the benefits of reduced liquid nitrogen consumption and more precise cooling. These advantages are particularly noteworthy for efficiently machining challenging materials. However, prevailing research on internal supply cooling through tools predominantly concentrates on aspects such as tool wear and surface integrity, with a relatively limited exploration of material removal mechanisms. The material removal process stands as a crucial factor influencing cutting stability and surface smoothness. Thus, this study focuses on the Ti-6Al-4 V alloy, utilizing numerical modeling to investigate the impact of liquid nitrogen cooling methods on the cutting deformation zone. In addition to its benefits for difficult-to-machine materials, internal supply cooling through the tool presents a promising avenue to enhance machining efficiency. Consequently, this study strategically selected the Ti-6Al-4 V alloy as the research subject, employing numerical modeling to delve into the influence of liquid-nitrogen cooling methods on the cutting deformation zone. Furthermore, employing a combination of cutting experiments and simulations, we analyzed the evolution of temperature fields and microstructures within the deformation zone to elucidate the chip formation mechanism under liquid nitrogen cooling conditions. The outcomes of this investigation reveal that in comparison to liquid nitrogen external supply cooling, internal supply cooling through the tool effectively restrains chip serration, thereby contributing to an enhancement in machining quality. The analysis demonstrates that, under conditions of internal supply cooling through the tool, chip formation is predominantly influenced by the adiabatic shear effect induced by low temperatures. In contrast, under external supply cooling conditions, susceptible to the low-temperature embrittlement effect, the chip's free surface tends to undergo brittle cracking. This shift in the chip formation mechanism toward the co-dominance of adiabatic shear and brittle cracking results in a more pronounced serration of the chips. This study establishes a theoretical foundation and guides the industrial application of cryogenic machining.