Low Temperature Gradient Research Articles

Integrated Control of Thermal Residual Stress and Mechanical Properties by Adjusting Pulse-Wave Direct Energy Deposition

Directed energy deposition with laser beam (DED-LB) components experience significant residual stress due to rapid heating and cooling cycles. Excessive residual tensile stress can lead to cracking in the deposited sample, resulting in service failure. This study utilized digital image correlation (DIC) and thermal imaging to observe the in situ temporal evolution of strain and temperature gradients across all layers of a deposited 316 L stainless steel thin wall during DED-LB. Both continuous-wave (CW) and pulsed-wave (PW) laser modes were employed. Additionally, the characteristics of thermal cracks and geometric dislocation density were examined. The results reveal that PW mode generates a lower temperature gradient, which in turn reduces thermal strain. In CW mode, the temperature–stress relationship curve of the additive manufacturing sample enters the “brittleness temperature zone”, leading to the formation of numerous hot cracks. In contrast, PW mode samples are almost free of cracks, as the metal avoids crack-sensitive regions during solidification, thereby minimizing hot crack formation. Overall, these factors collectively contribute to reduced residual stress and improved mechanical properties through the adjustment of pulsed-wave laser deposition.

Evolutionary Mechanism of Solidification Behavior in the Melt Pool during Disk Laser Cladding with 316L Alloy

Laser cladding is an emerging environmentally friendly surface-strengthening technology. During the cladding process, the changes in molten pool temperature and velocity directly affect the solidification process and element distribution. The quantitative revelation of the directional solidification mechanism in the molten pool during the cladding process is crucial for enhancing the quality of the cladding layer. In this study, a multi-field coupling numerical model was developed to simulate the coating process of 316L powder on 45 steel matrices using a disk laser. The instantaneous evolution law of the temperature and flow fields was derived, providing input conditions for simulating microstructure evolution in the molten pool’s paste zone. The behavior characteristics of the molten pool were predicted through numerical simulation, and the microstructure evolution was simulated using the phase field method. The phase field model reveals that dendrite formation in the molten pool follows a sequence of plane crystal growth, cell crystal growth, and columnar crystal growth. The dendrites can undergo splitting to form algal structures under conditions of higher cooling rates and lower temperature gradients. The scanning speed of laser cladding (6 mm/s) has minimal impact on dendrite growth; instead, convection within the molten pool primarily influences dendrite growth and tilt and solute distribution.

Ablative property and mechanism of pitch-based carbon fiber modified C/C composites with high thermal conductivity

The novel C/C composites with thermal transport function were prepared using the mesophase-pitch carbon fibers (CFMP) as the thermal diffusion channels. The introduction of CFMP greatly improved the microstructure, thermal properties, and ablative resistance of the C/C composites. During the graphitization process, compared with PAN fibers (CFPAN), CFMP was more likely to be graphitized to form a highly ordered three-dimensional graphite structure. The highly organized microcrystalline structure of CFMP resulted in a tight interface with PyC that lessened the likelihood of flaws and cracks during graphitization. CFMP, which acted as a thermal conduction skeleton, significantly improved the thermal conductivity of C/C composites. After 3000 °C HTT, the thermal conductivity of C/C-3000-Z composites was increased to 51.70 and 225.02 W/(m K) in the XY and Z planes, respectively. During the ablation process, C/C-3000-Z specimen exhibited a lower temperature gradient and less thermal stress owing to the outstanding thermal properties and fewer defects. After 30 s ablation, the temperature difference of surface and backside was only 495.9 °C, and the mass and linear ablation rates were 0.3 μm/s and 0.9 mg/s, respectively.

Simulation analysis of gas-solid two-phase flow and reaction in a novel catalytic cracking reactor

A gas-solid two-phase flow reaction model was developed to evaluate the performance of a novel catalytic cracking reactor in the residue-to-chemicals (RTC) process. Coupled TFM, EMMS drag, and 12-lump kinetic models were employed to simulate the flow reaction process. The reaction temperature and product yields at the reactor exit aligned well with real industrial RTC reactor test results, indicating the reliability and effectiveness of the coupling model. Catalyst particles formed an internal circulation structure in the reactor, increasing the instantaneous catalyst-to-oil ratio. The reactor exhibited low axial and radial temperature gradients with higher reaction temperatures, accelerating the catalytic cracking rate and enhancing the selectivity for high-value products. The effects of the catalyst-to-oil ratio, catalyst inlet temperature, and feedstock mass flow rate on the flow reaction process were optimized. Results showed that both the catalyst-to-oil ratio and catalyst inlet temperature influenced the overall catalyst velocity distribution. Within the limit range, increasing the catalyst-to-oil ratio increased feedstock conversion, gasoline, LPG, dry gas, and coke yields, but decreased diesel yield. Conversely, increasing the feedstock mass flow rate showed opposite trends. Different trends in product yields were observed with varying inlet catalyst temperatures, with optimal product distribution at 973.15 K.

Crystal Growth of LiNa5Mo9O30 Crystals of High Optical Quality

The bulk of the LiNa5Mo9O30 (LNM) crystals were successfully grown in the [010] and [001] directions without internal inclusions and cracks, using the Czochralski method with a low temperature gradient. The crystal grown in the [010] direction showed a tendency to twinning. The crystal grown in the [001] direction demonstrated high structural perfection (FWHM = 13″) for the (001) plane and high optical quality Δn ≈ 2 × 10−5. The laser-induced damage threshold was measured along a, b and c axes and was 12.2, 27.0 and 27.5 J/cm2, respectively. The thermo-optical coefficient dn/dT was measured for the main crystallographic axes, which was −5.75 × 10−6, −20.2 × 10−6 and 3.65 × 10−6 K−1 along the a, b and c axes, respectively. The second harmonic generation (SHG) was conducted in the crystalline LNM sample. The maximum efficiency value of 3.5% at a pump power of 12 W was achieved.

3D Soft Architectures for Stretchable Thermoelectric Wearables with Electrical Self-Healing and Damage Tolerance.

Flexible thermoelectric devices (TEDs) exhibit adaptability to curved surfaces, holding significant potential for small-scale power generation and thermal management. However, they often compromise stretchability, energy conversion, or robustness, thus limiting their applications. Here, the implementation of 3D soft architectures, multifunctional composites, self-healing liquid metal conductors, and rigid semiconductors is introduced to overcome these challenges. These TEDs are extremely stretchable, functioning at strain levels as high as 230%. Their unique design, verified through multiphysics simulations, results in a considerably high power density of 115.4µWcm⁻2 at a low-temperature gradient of 10°C. This is achieved through 3D printing multifunctional elastomers and examining the effects of three distinct thermal insulation infill ratios (0%, 12%, and 100%) on thermoelectric energy conversion and structural integrity. The engineered structure is lighter and effectively maintains the temperature gradient across the thermoelectric semiconductors, thereby resulting in higher output voltage and improved heating and cooling performance. Furthermore, these thermoelectric generators show remarkable damage tolerance, remaining fully functional even after multiple punctures and 2000 stretching cycles at 50% strain. When integrated with a 3D-printed heatsink, they can power wearable sensors, charge batteries, and illuminate LEDs by scavenging body heat at room temperature, demonstrating their application as self-sustainable electronics.

Analysis of Soot Deposition Effects on Exhaust Heat Exchanger for Waste Heat Recovery System

This study investigates the thermal–hydraulic behavior and deposition characteristics of a shell and tube exhaust heat exchanger using a CFD-based predictive model of soot deposition. Firstly, considering the influences of thermophoretic, wall shear stress, and other deposition and removal mechanisms, a predictive model is developed for long-term performance of heat exchangers under soot deposition. Then, the variations in exhaust heat exchanger performance during a 4 h deposition period are simulated based on the model. Subsequently, the variation of deposition distribution and different deposition velocities are also evaluated. Finally, an analysis of the long-term performance of the exhaust heat exchanger under varying gas velocities and temperature gradients is conducted, revealing the performance variations under all engine-operating conditions. Results show that the deterioration in normalized relative j/f1/2 varies from 5.26% to 24.91% under different work conditions, and the exhaust heat exchanger with high gas velocity and low temperature gradient exhibits optimal long-term performance.

Hot Crack Formation Mechanism and Inhibition of a Novel Cobalt-Based Alloy Coating during Laser Cladding.

Laser cladding provides advanced surface treatment capabilities for enhancing the properties of components. However, its effectiveness is often challenged by the formation of hot cracks during the cladding process. This study focuses on the formation mechanism and inhibition of hot cracks in a novel cobalt-based alloy (K688) coating applied to 304LN stainless steel via laser cladding. The results indicate that hot crack formation is influenced by liquid film stability, the stress concentration, and precipitation phases. Most hot cracks were found at 25°-45° high-angle grain boundaries (HAGBs) due to the high energy of these grain boundaries, which stabilize the liquid film. A flat-top beam, compared to a Gaussian beam, creates a melt pool with a lower temperature gradient and more mitigatory fluid flow, reducing thermal stresses within the coating and the fraction of crack-sensitive, high-angle grain boundaries (S-HAGBs). Finally, crack formation was significantly inhibited by utilizing a flat-top laser beam to optimize the process parameters. These findings provide a technical foundation for achieving high-quality laser cladding of dissimilar materials, offering insights into optimizing process parameters to prevent hot crack formation.

Cellulose binary coatings with spherical envelope structure via structure rearrangement in ball milling for integrated radiative cooling-electricity generation

Passive daytime radiative cooling is a zero-energy consumption cooling technology, which can dissipate heat to outer space via infrared radiation. Recently, coupling radiative cooling technology and thermoelectric devices to generate electricity has attracted much attention. However, existing radiative cooling integrated thermoelectric devices still suffer from low-temperature gradient and output voltage. Here, based on the Mie scattering and internal reflection enhancing principle, an impact-inducing geometry reconstruction approach was proposed to fabricate hierarchical nanostructured cellulosic coatings with good daytime cooling performance to achieve stable electricity generation function, which can be realized by using a scalable and facile wet ball milling technology. Guided by the theoretical simulations of the finite difference time domain method (FDTD), the cellulose and TiO2 nanoparticles can assemble into spherical envelope structured coatings drying by the shear, impact, and friction interaction in the ball milling process, dramatically enhancing the Mie scattering and internal reflection of coatings. The cellulosic coatings exhibit sunlight reflectivity of 0.962 and infrared emissivity of 0.94, resulting in a daytime radiative cooling efficiency of 5.9 °C under direct sunlight. Energy Plus stimulation demonstrated 35 % cooling energy and 468.9 kWh of cooling energy can be saved annually in China. Meanwhile, this cellulosic coating-based thermoelectric device can deliver a high voltage output of 150 mV under 1 Sun due to the strong bonding and high-temperature gradient formation (30 °C), which is higher than previous reports. This study will facilitate the development of sustainable power generation device for the goal of green future.

Evaluation of heat transfer conditions during polydisperse gas–solid flow in an industrial fluidised bed reactor

Knowledge of heat transfer conditions in large-scale circulating fluidised bed reactors plays an essential role in their proper design and optimization of theirs. This work presents an evaluation of the heat transfer conditions taking into account the coordinate height of the furnace chamber and the fluidised bed flow regime in the reactor. Experimental tests used method and measurement technique that provides reliable temperature data. The vertical and horizontal temperature profiles were obtained at different 966MWth fluidised bed reactor operating conditions. Four characteristic areas can be distinguished in the furnace chamber: the bottom region with a high-temperature gradient from 10.6 °C/m to 22.7 °C/m; the dense region with a medium temperature gradient from 4.7 °C/m to 7.3 °C/m; the dilute area with the lowest temperature gradient from 0.7 °C/m to 3.1 °C/m and the exit region with a temperature gradient (4.3 °C ≤ grad T ≤ 9.6 °C) similar to dense region. The horizontal temperature profiles confirmed a core-annular flow structure inside the furnace chamber. At the pressure drop below 5 kPa, the low variation of average temperature (from ±0.7 °C to ±4.2 °C) inside the furnace chamber of the CFB reactor was observed. As a result of fly ash recirculation of 3.86 kg/s, the lowest temperature gradient 0.2 °C/m was achieved in the bottom region of the furnace chamber. In the range of bed material circulation rates of 32 to 68 were registered temperature fluctuations 115 °C. The experimental results also showed the variation of the bed temperature was small and kept at a very low level of ±13 °C whereas the fluidised bed reactor was operated with a fluidisation velocity range of 1.8 to 2.4. Obtained findings provide unique data on heat transfer conditions in industrial facilities and thus fill the gap in literature data for CFB reactors. Based on main tests carried out in a large-scale CFB reactor, it can be concluded that detailed experimental data on thermal conditions provide important information to validate guidelines and for verifying empirical relationships, which are used in the design, optimization, and scaling of heat transfer surfaces in commercial fluidised bed reactors.

Statistical Interdependence between Daily Precipitation and Extreme Daily Temperature in Regions of Mexico and Colombia.

We study the statistical interdependence between daily precipitation and daily extreme temperature for regions of Mexico (14 climatic stations, period 1960-2020) and Colombia (7 climatic stations, period 1973-2020) using linear (cross-correlation and coherence) and nonlinear (global phase synchronization index, mutual information, and cross-sample entropy) synchronization metrics. The information shared between these variables is relevant and exhibits changes when comparing regions with different climatic conditions. We show that precipitation and temperature records from La Mojana are characterized by high persistence, while data from Mexico City exhibit lower persistence (less memory). We find that the information exchange and the level of coupling between the precipitation and temperature are higher for the case of the La Mojana region (Colombia) compared to Mexico City (Mexico), revealing that regions where seasonal changes are almost null and with low temperature gradients (less local variability) tend to display higher synchrony compared to regions where seasonal changes are very pronounced. The interdependence characterization between precipitation and temperature represents a robust option to characterize and analyze the collective dynamics of the system, applicable in climate change studies, as well as in changes not easily identifiable in future scenarios.

The Effect of Scanning Strategy on the Thermal Behavior and Residual Stress Distribution of Damping Alloys during Selective Laser Melting.

The manufacture of damping alloy parts with stable damping properties and high mechanical performances in the selective laser melting (SLM) process is influenced by temperature evolution and residual stress distribution. Choosing an appropriate scanning strategy, namely the specific trajectory along which the laser head scans powders within given area, is crucial, but clearly defined criteria for scanning strategy design are lacking. In this study, a three-dimensional finite element model (FEM) of the SLM process for manufacturing a WE43 alloy component was established and validated against the published experimental data. Eleven different scanning strategies were designed and simulated, considering variables such as scanning track length, direction, Out-In or In-Out strategy, start point, and interlayer variation. The results showed that scanning strategy, geometry, and layer number collectively affect temperature, melt pool, and stress outputs. For instance, starting scanning at a colder part of the powder layer could lead to a high peak temperature and low melt pool depth. A higher layer number generally results in lower cooling rate, a lower temperature gradient, a longer melt pool life, and larger melt pool dimensions. Changing the start point between scanning circulations helps mitigate detrimental residual stress. This work highlights the potential of analyzing various scanning strategy-related variables, which contributes to reducing trial-and-error tests and selecting optimal scanning strategies under different product quality requirements. This article can assist in the design of appropriate scanning strategies to prevent defects such as element loss due to evaporation, poor bonding, and deformation or cracking from high residual stress. Additionally, identifying stress concentration locations and understanding the effects of geometry and layer number on thermal and mechanical behaviors can assist in geometry design.

High-performance functional coatings manufactured by integrated extremely high-speed-rate laser directed energy deposition with interlayer remelting

Extremely high-speed-rate laser directed energy deposition has attracted considerable attention for large-scale industrial component manufacturing owing to its outstanding fabrication efficiency. However, interlayer metallurgical defects and thickness fluctuation stacking caused by the previous non-uniform rough surface layer hinder the preparation of customized thicknesses of large-scale components with high performance. Herein, an integrated extremely high-speed-rate additive manufacturing technology, that is, extremely high-speed-rate laser-directed energy deposition accompanied by extremely high-speed-rate laser remelting, is proposed to eliminate porosity and reconstruct the microstructure of multilayer parts. The remelted specimens exhibited uniform roughness and ultrafine grains when defocusing amount was less than zero. The relatively lower temperature gradient G and morphology factor G/R in the remelting process led to more favorable subcooling, which further promoted more nucleation sites and contributed to grain refinement and columnar-to-equiaxed transition. A multilayer 316 L stainless steel material with an interlayer remelting treatment was further prepared, and a typical heterogeneous structure dominated by ultrafine equiaxed grains was obtained. The multilayer specimen characterized by such a special structure exhibited a higher yield strength of 546 MPa, along with a ductility of 49.1 %. This novel integrated manufacturing technology highlights a new strategy that can expand the extremely high-speed-rate additive manufacturing window and achieve simultaneous improvements in the manufacturing efficiency and performance of large-scale components.

Snowpack variations and their hazardous effects under climate warming in the central Tianshan Mountains

Climate change alters snowpack evolution, which in turn influences the likelihood of snow avalanches and flood risks. The lack of systemic observational data on key snow characteristics in high mountains remains a scientific challenge in terms of systematically elucidating the dynamic chain of variations in climate–snowpack–snow disasters. This restricts our understanding and poses challenges in the prediction of snow-related disaster risks. As such, this study analysed the variations of temperature and snowfall and the physical characteristics of snowpacks based on ground-based observations from the Kunse River Valley situated in the Tianshan Mountains from 1967 to 2021. The results reveal that the temperature increased significantly by 0.32 °C per decade (p < 0.01) during the snow season, along with more extreme snowfall events. The snow-cover duration was observed to have been shortened by 4.77 d per decade (p < 0.01) from 1967 to 2021, which is characterised by later snow-cover onset and earlier snowmelt. Concurrently, average and maximum snow depths increased along with an increase in peak snow water equivalent, thus indicating a higher frequency of extremely scarce or abundant snow years. The low snowpack temperature gradient and earlier snowmelt dates in spring lead to earlier occurrences of snowmelt floods and wet avalanches. As the risks of these events increase, they pose greater threats to farmlands, road transportation, water–electricity infrastructure and several other human activities. Therefore, these insights are critical for providing vital information that can deepen our understanding of the impact of climate change on snowpack characteristics and improve management strategies for snow-related disaster prevention and mitigation.

Transcriptome: New perspective for the rational planting of Dendrobium nobile and the improvement of medicinal quality through cold stimulation

Temperature affects the growth and accumulation of carbohydrate in plants. To study the response of Dendrobium nobile to cold stimulation, by using room temperature as the control, four low-temperature gradients (8 °C, 4 °C, 0 °C, −4 °C) were set to investigate the physiological changes and polysaccharide content of D. nobile. The results showed that under −4 °C treatment, the plant suffered severe damage and normal physiological activities were inhibited, resulting in inability to grow normally. Meanwhile, treatment at 0 °C for 4 d significantly increased the accumulation of polysaccharides in D. nobile (an increase of 56.18 % compared to CK), and the plant can grow normally after relieving cold stimulation. To explore the mechanism of its promoting polysaccharide accumulation, we conducted transcriptome analysis of D. nobile in this treatment. The results showed that TPP6, DPE1, PGMP, BAM3 genes in the starch and subcrosse metropolis; The pel gene in pentose and glucose conversions and transcription factors such as bHLH, MYB, and WRKY were significantly upregulated, thereby promoting the accumulation of polysaccharides in D. nobile. This study provides new perspective into the low-temperature adaptability of D. nobile and lays the foundation for further research on the biosynthetic pathways of D. nobile polysaccharides.

Effect of AC/DC mixed current waveform on surface oxidation, microstructure and mechanical properties of TIG welded TC4 titanium alloy

Coarse β-grains and severe surface oxidation are major factors plaguing the comprehensive properties of tungsten inert gas (TIG) welded joints of titanium alloy. To improve the performance of welded joints, a novel current waveform, alternating current/direct current (AC/DC) mixed current waveform which was named Mix-TIG was proposed. In Mix-TIG, the oxide film on the weld surface is broken up by the cathodic crushing effect. Cyclic variations of the current waveform produce stronger arc stirring and more intense oscillations in the molten pool which results in grain refinement. In addition, the lower temperature gradient in the melt pool due to the smaller heat input in Mix-TIG also contributes to grain refinement. The elongation and microhardness of the Mix-TIG were increased.

Flow-shear destabilization of multiscale electron turbulence

The impact of sheared E×B flow on multiscale turbulence is studied with nonlinear gyrokinetic simulations. Simulations are based on DIII-D-like, high-confinement mode (H-mode) pedestal parameters in the regime of low ion temperature gradient drive, where there is a broad spectrum of electron temperature gradient (ETG)-driven turbulence. It is found that E×B shear can have a significant effect on ETG-driven electron transport, with an unexpected transition from a turbulence stabilization regime at moderate to large shearing rates γ E to a novel turbulence destabilization regime at low levels of γ E . In the turbulence stabilization regime, the electron energy flux decreases monotonically with γ E , even when γ E is small compared to electron mode growth rates. The stabilizing effect comes dominantly from the electron, not ion, gyrokinetic equation. In the novel destabilization regime, reduction of zonal energy results from the interaction of γ E -modulated nonlinear drive in the zonal ion gyrokinetic equation, increasing the electron transport over a broad range of shearing rates. Neither of these effects have been observed in previous electron-scale simulations.

Study Outlines Challenges of Repurposing Oil and Gas Wells for Geothermal Applications

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 215751, “Challenges for Repurposing Oil and Gas Wells for Geothermal Applications,” by Livio Santos, SPE, and Arash Dahi Taleghani, SPE, The Pennsylvania State University. The paper has not been peer reviewed. _ This work provides insights into the technical and economic viability of repurposing oil and gas wells for geothermal energy production for direct heating. The potential benefits—especially for areas that are highly dependent on fossil fuels for heating—and challenges of this approach are assessed, while technical, market, and policy barriers for future development are identified. Repurposing oil and gas wells for geothermal energy requires a multidisciplinary approach that involves expertise in geology, engineering, and regulatory affairs. Introduction Repurposing abandoned wells for power generation in geothermal energy projects can present challenges because of the low temperatures associated with these wells. The low temperature gradients and thermal energy available in such wells have been found to limit overall power-generation potential. The same low-temperature geothermal resources can still be used effectively, however, for community heating applications. Community heating systems have lower temperature requirements compared with those necessary for power generation and are compatible with available heat from low-temperature geothermal sources. In particular, closed-loop geothermal systems, specifically designed for community heating, offer several advantageous features. The closed-loop design ensures that the fluid remains contained within the system. These systems are environmentally compatible because they do not extract or discharge water from natural sources. Additionally, with better control over the working fluid and heat-exchange process, closed-loop systems deliver optimized system performance, energy efficiency, and cost savings. They also require less maintenance and feature lower operational risks because of the closed circuit. Closed-loop systems offer fluid-selection flexibility and streamlined regulatory compliance. Not all abandoned wells are suitable for repurposing, however. Thorough feasibility assessments and well-integrity evaluations are necessary to ensure that the abandoned well is structurally sound, has the appropriate depth and geological characteristics, and can extract geothermal heat effectively. The condition of the well casing, cementing, and any potential wellbore damage also must be evaluated. An economic analysis is performed to assess the financial viability and cost-effectiveness of the geothermal community heating system. Finally, an environmental impact assessment evaluates the environmental consequences of the geothermal community heating system.

Optimal HDR exploitation siting of gravity heat pipe geothermal systems via reservoir simulation

Gravity heat pipe system has previously been proven as an environmental and efficient technology in exploiting hot dry rock. However, it is unclear what geothermal reservoir siting is more favorable for the system’s heat extraction performance. Herein, we analyzed the influences of geothermal field siting (rock property and reservoir environment) on heat extraction performance of gravity heat pipe systems through a 3D thermal–hydraulic coupled model. It is found that rock properties have huge influences on heat compensation, heat extraction ratio and heat compensation ratio. Low rock density, low rock specific heat capacity and high thermal conductivity could increase heat compensation, heat extraction ratio and heat compensation ratio. It is also found that geothermal reservoir environment affects the heat extraction rate seriously. High initial temperatures and low temperature gradients increase heat extraction rates. Geothermal reservoir pressure affects the heat extraction performance slightly, and low initial pressures increase heat extraction rate. The study results would provide suggestions on deep geothermal exploitation locations.

Investigation of 316L microstructure evolution mechanism and mechanical properties in dual-laser powder bed fusion with controllable remelting time interval

Remelting has a significant effect on controlling microstructure and enhancing properties of components prepared by laser powder bed fusion. In order to reveal the mechanism of the effect of remelting time intervals, this study employed a dual-laser powder bed fusion equipment to ensure precise and controllable time intervals of remelting. The effects of intervals (2 ms, 5 ms, and 50 ms) on substructure morphology, microstructure and mechanical properties of 316L were analyzed. The results indicate that the grain size ranged from 13.03 μm to 26.55 μm due to the influence of initial temperature at different remelting intervals on grain size. Additionally, the composition ratio between columnar and cellular substructure varies with the time interval, which greatly influences mechanical properties. Longer intervals favor columnar substructures in high-temperature gradients, and dislocation motion is impeded, leading to an increased strength of up to 689.6 MPa. Shorter intervals promote cellular substructures in low-temperature gradients, and dislocations move smoothly along the boundaries of substructure, leading to an elongation of up to 49.3 %. Therefore, a novel method for controlling microstructure and properties is provided in this study utilizing the precise controllable remelting time intervals of dual-laser powder bed fusion.