Stage Of Solidification Research Articles

Achieving excellent strength–ductility combination of Al-aided Mg–Gd–Al–Zr–Zn alloys fabricated by cold metal transfer-based wire-arc directed energy deposition via uniform equiaxed grains and multiple precipitates

Limited ductility consistently poses a challenge for high-strength Mg–RE (rare earth) structures prepared by additive manufacturing. Particularly following heat treatment, while the strength of the Mg–RE alloy experiences a substantial increase, there is a noteworthy decrease in its ductility. Herein, a novel Mg–Gd–Al–Zr–Zn thin wall was successfully fabricated by cold metal transfer-based wire-arc directed energy deposition (CMT-WA-DED) and Al alloying. The microstructural evolution and mechanical properties of deposited and heat-treatment alloys were elucidated systematically. By adding Al element, Al2Gd and Al–Zr phases with thermal stability were precipitated in the deposited alloy. During the solidification or heat treatment stage, Al2Gd and Al–Zr phases could pin grain boundaries to restrict grain growth. The as-deposited alloys exhibited fully equiaxed grains at different heights and orientations. Thus, the thin wall exhibited good isotropic performance. After the heat treatment, the grain size only slightly grew and no abnormal grain growth was observed. Various morphologies of β precipitation phases were discovered along grain boundaries and within the grains. Additionally, a high density of β' and β1 phases within the grains and β phases along the grain boundary played pivotal roles in enhancing the mechanical strength of the Mg–Gd–Al–Zr–Zn alloy. The alloys exhibited an excellent combination of strength and ductility with ultimate tensile strength of 340 ± 7 MPa, yield strength of 212 ± 5 MPa, and elongation of 12.7 ± 0.9 %. This work provides theoretical and practical reference value for the Mg–RE structures obtaining an excellent combination of strength and ductility prepared by additive manufacturing.

Cyclic and uniaxial tensile properties of superelastic niti shape memory alloy cables

This study investigates the impact of various factors, including annealing duration, strain amplitude, cyclic loading, loading rate, and pre-training, on the mechanical properties of Nickel–Titanium shape memory alloy (SMA) cable. The primary focus is on evaluating their recovery ability and energy dissipation capabilities. The tested SMA cable has an outer diameter of 9 mm and a 7 × 7 configuration. The variation of strength, stiffness, residual strain, hysteretic energy, and equivalent viscous damping ratio of SMA cable with the loading cycle is analyzed. Furthermore, the impact of various annealing durations on the tensile strength and elongation of both SMA cables and wires was examined through monotonic tensile tests. The results indicate that the annealing duration considerably affects the superelastic behavior of SMA cables by shifting the stress-strain loops down and widening them. The recovery ability of SMA cable degrades more progressively with increasing loading amplitude and the number of loading cycles. The mechanical properties gradually stabilized after 20 times of constant strain amplitude loading and unloading training. The strain selection for cyclic training should not make the SMA cable in the martensite hardening stage. The recovery ability and peak stress of SMA cable can be significantly improved by pre-training. With the increase of annealing duration, the tensile strength of the SMA cable decreases gradually. Compared with SMA wire, SMA cable has better ductility and robustness and provides sufficient restoring force under large deformation.

From crack-prone to crack-free: Eliminating cracks in additively manufacturing of high-strength Mg2Si-modified Al-Mg-Si alloys

Large solidification ranges and coarse columnar grains in the additively manufacturing of Al-Mg-Si alloys are normally involved in hot cracks during solidification. In this work, we develop novel crack-free Al-Mg2Si alloys fabricated by laser powder-bed fusion (L-PBF). The results indicate that the eutectic Mg2Si phase possesses a strong ability to reduce crack susceptibility. It can enhance the grain growth restriction factor in the initial stage of solidification and promote eutectic filling in the terminal stage of solidification. The crack-free L-PBFed Al-xMg2Si alloys (x = 6 wt.%, 9 wt.%, and 12 wt.%) exhibit the combination of low crack susceptibility index (CSI), superior ability for liquid filling, and grain refinement. Particularly, the L-PBFed Al-9Mg2Si alloy shows improved mechanical properties (e.g. yield strength of 397 MPa and elongation of 7.3 %). However, the cracks are more likely to occur in the region near the columnar grain boundaries of the L-PBFed Al-3Mg2Si alloy with a large solidification range and low eutectic content for liquid filling. Correspondingly, the L-PBFed Al-3Mg2Si alloy shows poor bearing capacity of mechanical properties. The precise tuning of Mg2Si eutectic content can offer an innovative strategy for eliminating cracks in additively manufactured Al-Mg-Si alloy.

Formation and effect of intermetallic compounds in the vacuum arc melting of titanium/copper alloy

The effect of Ti element content on the precipitation of intermetallic compounds, microstructure and mechanical properties of Ti–Cu alloy samples during vacuum arc melting was studied. The results showed that when the TC4:Cu mass ratio were 1:20, 1:10, and 3:20, the tensile strength of the sample were 638 MPa, 945.5 MPa, 914.9 MPa, the elongation were 21.1 %, 3.5 %, 0.9 %, and the microhardness were Hv 195.6, Hv 259.01, Hv 275.6, respectively. The solidification behavior of the melt pool and the precipitation behavior of IMCs were also studied. When the Ti content exceeds the solid solubility of titanium in copper, dendrite segregation will occur during the solidification process, resulting in the precipitation of a large number of IMCs. The IMCs precipitated in Ti–Cu melting samples include TiCu, Ti3Cu4, TiCu3, and TiCu4. Among them, TiCu4 is precipitated from the solid solution due to the decrease in melt temperature in the later stage of solidification, while TiCu, Ti3Cu4, and TiCu3 are produced by liquid-phase precipitation or transformation reaction of the TiCu phase. TiCu and Ti3Cu4 are the main causes of alloy fracture.

Simulation of gas porosity formation and interaction with dendrite and eutectic structures during solidification of Al-Si alloys

A two-dimensional (2-D) multi-phase cellular automaton (CA)-finite difference (FD)-lattice Boltzmann (LB) coupled model is developed to simulate the hydrogen pore formation during dendritic and eutectic solidification of hypoeutectic Al-Si alloys. In this model, the dendrite and eutectic structures are simulated using a CA technique. The solute diffusion is solved by the FD method. The nucleation, growth, and motion behavior of gas pore, and hydrogen transport are simulated by a LB Shen-Chen scheme. It is found that the pores can grow fully but compete in the primary dendrite growth stage. Conversely, pores newly nucleated in residual inter-dendrite liquid during the eutectic solidification stage grow restrictedly and independently. Pore shape severely deformed by the compression of the surrounding solid structures. Moreover, the effects of the initial Si composition, initial hydrogen concentration and cooling rate on the pore formation are qualitatively and quantitatively studied. It is found that the initial Si composition significantly impacts on the pore size and distribution, but little effect on the porosity percentage which decreases markedly with the decreasing initial hydrogen concentration and increasing cooling rate. Comparison reveals that the simulated microstructure morphological characteristics and the predicted porosity percentage agree well with the experimental observation reported in the literature.

Peculiarities of steel hardening under deformation conditions with external influence of a magnetic field

The strain resistance of a metal, its intensity of hardening, directly depends on the evolution of defects in the crystal lattice. The positive influence of a magnetic field (MF) on the movement of dislocations and their interaction with stoppers (magnetoplastic effect) is known. For the practical use of MF in forging technologies, generalized data on the strengthening of metals during plastic deformation are required. The results of using a constant MF with induction up to 1,2 T in the processes of testing samples for tension and compression were studied. Tensile tests were carried out on samples of steels St3, 20, U8, 40Cr, 09Cr16Ni4Nb, X10CrNiTi18-10, copper M3 and compression tests on steels St3, 09Cr16Ni4Nb, X10CrNiTi18-10, copper M3. Curves of metal hardening during deformation are plotted in the coordinates flow stress – logarithmic strain. The flow stress is determined by the ratio of the load to the cross-sectional area of the sample valid for a given moment of testing under uniform deformation. The change in flow stress of metals is described by the power function of the Ludwik-Hollomon equation. In tension and compression of ferromagnetic steels St3, 20, 40Cr, U8 and 09Cr16Ni4Nb, the impact of MF leads to an increase in the intensity of their hardening. This is most evident in hardened or high-strength steels. But for St3 steel softened by annealing, the effect is the opposite - in MF the intensity of hardening is somewhat less. Tension in MF of paramagnetic steel X10CrNiTi18-10 showed an increase in the intensity of hardening, but compression showed its decrease. Tension and compression of M3 copper in MF occur with a slight decrease in the intensity of hardening. The experiments carried out revealed the main effect of MF at the initial stage of deformation. The hardening curves were divided into straight and parabolic sections with the hardening coefficients determined for each of them. The main effect of MT on the primary stage of linear hardening has been revealed, where a decrease in the intensity of hardening (St3, 40Cr, X10CrNiTi18-10, M3), an increase (St3 and X10CrNiTi18-10) or a reduction (St3 annealed) in the duration of this stage is observed. Keywords: magnetoplasticity, tension, compression, hardening, stress, strain.

Analysis of acoustic emission signal in the tensile process of weld-bonding joint and its damage model

ABSTRACT This paper analysed the acoustic emission signals acquired during the tensile test of DP780 weld-bonding joints, and the Gaussian equation was used to fit the cumulative hits and the load to establish relevant damage models. The process parameters were designed based on the Box-Behnken Design method, and the wavelet packet was used to decompose the collected AE signals. The results showed that, in the elastic stage, no AE signal emitted, and the AE signal was mainly concentrated in the plastic stage, the hardening stage and the failure moment of the weld nugget or the adhesive layer. At the failure instant of the adhesive layer or the weld nugget, the signal amplitude was the largest, and the failure frequency was mainly concentrated in the middle and low-frequency bands. The failure of the adhesive layer and the weld nugget could be distinguished from the energy distribution diagrams, and the established damage model could reflect the damage state of the specimen. The results proved that the acoustic emission technique can provide support for the non-destructive testing of the weld-bonding joint.

Cyclic behavior and damage mechanism of 304 austenitic stainless steel under different control modes

In this work, low cycle fatigue experiments under both strain and stress control modes with different loading levels were conducted on 304 austenitic stainless steel at ambient temperature to discuss the influence of loading mode and level on the cyclic response and physical mechanism. The results demonstrated that the cyclic response generally exhibited three stages: primary cyclic hardening, subsequent cyclic softening, and the secondary hardening finally. The degree of each hardening and softening stage was depended on not only the loading modes but also the strain/stress level. Accelerated cyclic softening and retarded secondary hardening occurred under the stress mode, which made a higher low-cycle fatigue life during stress cyclic loading than that for the strain control mode, especially at relatively high strain/stress level. The secondary hardening stage, occupying the main portion of the lifetime, was proved to be associated with the development of martensitic phase and the extension and intersecting of stacking faults or micro-twin.

Static-dynamic damage mechanism and self-heating effect of a clean elastic polyurethane grouting material for trenchless rehabilitation under high stresses

Compared with traditional excavation rehabilitation, trenchless grouting rehabilitation technology has the advantages of fast, precise, and low-carbon, which has a broad application prospect in wind turbine foundation rehabilitation. In this work, a non-toxic, environment-friendly, fast-setting, high-strength, and high-toughness elastic polyurethane (PU) grouting material was proposed, and the static-dynamic damage mechanism and self-heating effect under high stress were studied by DMA, SEM, static-dynamic compression, and self-heating monitoring tests. The results show that the static compressive properties increased in a power function relationship with increasing strain rate. The dynamic compression fatigue process can be divided into adjustment stage (Stage I), viscoelastic development stage (Stage II) and failure stage (Stage III) or cyclic hardening stage (Stage III*). At 41.57 MPa and 36.95 MPa, fatigue damage parameters increased slowly in Stage I and Stage II, and sharply in Stage III. The stiffness damage, loss factor, cumulative strain, and strain rate increased by more than 100% in Stage III. Fatigue failure dominated by vertical/slanting through-cracks, shed debris, drum deformation, etc. was closely related to temperature and loading. The failure temperature about 59.1 °C, which was higher than the glass transition temperature. At 32.33 MPa, fatigue damage parameters changed slightly and then stabilized, showing exponential relationships with cycles. The max temperatures were less than 15 °C. The slight temperature rise facilitated the adjustment of structure and cyclic hardening under cyclic loading. This work can guide the further engineering application and fatigue durability evaluation of PU grouting materials.

Ternary medium constitutive model of frozen rubber-reinforced expansive soil

The application of waste rubber for soil improvement is feasible, and the static and dynamic properties of rubber-reinforced soils have been extensively studied. However, the mechanical properties of frozen rubber-reinforced expansive soils have not been effectively studied due to the complexity of multiphase media under the action of multiple fields, and no applicable constitutive models describe them. In this paper, the stress-strain relationship model for frozen rubber-reinforced expansive soils is investigated over a range of strain rates from 0.18% to 0.3% and the following conclusions were obtained: (1) The structural model of the frozen rubber-reinforced expansive soil can be considered a ternary medium model that consists of elasto-brittle bonding elements, elasto-plastic friction elements and elastic friction elements. (2) The stress-strain relationship can be divided into three stages: linear elastic stage, elasto-plastic stage and strain softening (RC ≤ 15%) or hardening (RC = 20%) stage. (3) The rubber content has a greater influence on the stress-strain relationship. When the rubber content reaches 20%, the expression of the stress-strain curve changes from strain softening to strain hardening, at which time the rubber dominates. (4) The maximum shear strength of frozen rubber-reinforced expansive soil is obtained at 10% rubber content.

Gel‐Derived Amorphous Precursor Enables Homogeneous Pure‐Phase α‐FAPbI3 Films for Efficient and Stable Perovskite Solar Cells

AbstractPure‐phase α‐formamidinium lead iodide (α‐FAPbI3) perovskite solar cells (PSCs) possess potential high efficiency because of suitable bandgap. However, achieving high‐quality α‐FAPbI3 films during the spin‐coating process is challenging without anti‐solvent extraction, due to the spontaneous formation of the more stable δ‐FAPbI3 phase and the complexity of multi‐component perovskite precursor solutions. Here a gel precursor with an amorphous structure to eliminate the need for anti‐solvent extraction in achieving the homogeneous and highly oriented pure‐phase α‐FAPbI3 is devised films. The incorporation of N,N′‐dimethylpropyleneurea, and alkylammonium chloride results in extended iodoplumbate clusters in the perovskite precursor solution. In situ, spectroscopic analysis reveals that the emergence of the stable amorphous gel precursor during the initial solidification stage ensures a uniform solute distribution. This effectively prevents preferentially oriented growth in the crystal phase precursor, leading to a significant enhancement in film homogeneity. As a result, power conversion efficiencies of 24.17% for the PSC, and 19.3% for the module are achieved, along with superior operational stability, retaining 96.1% of their initial efficiency after 850 h at the maximum power point tracking. These demonstrate the best performance for the reported pure‐phase α‐FAPbI3 PSCs without anti‐solvent extraction, showing great promise for scalable manufacture.

Experimental characterization on fracture behavior of UHPMC under small-scale sample tensile testing: Acoustic emission monitoring and digital image correlation

Manufactured sand (MS) was used to partially replace the traditional quartz sand (QS) to prepare a novel ultra-high-performance manufactured sand concrete (UHPMC). To better understand the fracture damage mechanism of UHPMC, small-scale sample tensile tests were conducted to investigate the tensile behavior of three types of UHPMC (low strain hardening, low strain softening and high strain softening). Acoustic emission (AE) and digital image correlation (DIC) are employed simultaneously to monitor and assess the damage characteristics of UHPMC. The results indicate that the classical AE characteristic parameters (ringing counts, duration and b-value) provide a satisfactory result in identifying the feature stages of low strain hardening and high strain softening. Based on the Gaussian mixture model (GMM) and support vector machine (SVM), an automatic probability classification algorithm has been developed that achieves the quantitative categorization of three UHPMC cracking types (shear or tensile cracks). Among them, tensile damage is dominant during the entire loading process, whereas shear damage, including aggregate dislocation and fiber debonding and pullout, accumulates during the hardening and softening stages. DIC visualization and AE source localization complement each other in identifying crack distribution, contributing to further revealing the tensile damage mechanism of UHPMC. The results obtained in this study can provide data and theoretical support for fracture damage characterization and health monitoring of ultra-high-performance concrete materials under tensile conditions.

Experimental study on the effect of inverted aperture plate temperature on frosting characteristics under rising flow considering edge effect

To reduce the negative impact of frost formation on cold surfaces in low-temperature environments, metal wire mesh can be set in the air flow direction from the cold surface to reduce air humidity. To quantitatively determine the effectiveness of dehumidification after passing through a metal wire, the frosting process needs to be studied. To analyze the mechanism of frost formation under the horizontal wire mesh surface, the wire mesh was simplified as a flat plate with holes, or aperture plate, with plate temperature varying at a range of -15.0 °C to -5.0 °C. The results show that, as the plate temperature decreases, the droplet condensation and growth and droplet solidification stages gradually decrease, the average frost layer thickness and frost layer growth rate rise, and overall frost layer surface roughness increases. For a frosting duration of 1,800 s, compared to -5.0 °C, the average frost layer thickness from -7.5 °C to -15.0 °C inside the hole increased by 56.68 % and 156.41 %, while the plate edge region away from the hole increased by 40.76 % and 169.92 %, respectively. The reverse melting frequency gap between the inside hole region and the plate edge region away from the hole increases with the decreasing aperture plate temperature. At -15.0 °C, the reverse melting frequency inside the hole is 5.00 × 10−3 Hz lower than in the region of the plate edge away from the hole. The results of this article are beneficial for understanding the frosting process of wire mesh or perforated-fin heat exchanger.

Modeling Dendrite Coarsening and Remelting during Directional Solidification of Al-06wt.%Cu Alloy.

Research efforts have been dedicated to predicting microstructural evolution during solidification processes. The main secondary arm spacing controls the mushy zone's permeability. The aim of the current work was to build a simple sub-grid model that describes the growth and coarsening of secondary side dendrite arms. The idea was to reduce the complexity of the curvature distribution with only two adjacent side arms in concurrence. The model was built and applied to the directional solidification of Al-06wt%Cu alloy in a Bridgman experiment. The model showed its effectiveness in predicting coarsening phenomena during the solidification of Al-06wt%Cu alloy. The results showed a rapid growth of both arms at an earlier stage of solidification, followed by the remelting of the smaller arm. In addition, the results are in good agreement with an available time-dependent expression which covers the growth and coarsening. Such model can be implemented as a sub-grid model in volume average models for the prediction of the evolution of the main secondary arms spacing during macroscopic solidification processes.

Experimental study on the freezing process of water droplets for ice air jet technology

Ice air jet technology is one non-destructive, residue-free and environmentally friendly machining process. It is an efficient method to form ice particles by atomizing water droplets in ultra-low temperature environment. The freezing characteristics of water droplets in cryogenic gas and liquid nitrogen environment are visually analyzed, and the effects of droplet volume, ambient temperature are also studied. The results show that when water droplets freeze in a cryogenic gas environment, four distinct stages are observed, namely pre-cooling stage, recalescence stage, solidification stage, and deep cooling stage. However, when water droplets freeze in liquid nitrogen, the recalescence stage cannot be observed. For a 5 µl water droplet, it takes 68 s for water droplets to freeze into ice particles at − 20.36 °C, while it takes only 1.7 s in liquid nitrogen. During the freezing process, the water droplets form an ice shell outside and freeze inwardly. Ice particles may break up due to differences in solubility and density. With the increase of volume the time spent on pre-cooling stage and freezing stage both increases. For the large latent heat of water phase transformation, the solidification stage time is greatly affected by the volume of water droplets. When the ambient temperature drops from − 10.67 °C to − 24.68 °C, the freezing time of 5 µl water droplets decreases by 45.5%, indicating that the ambient temperature has a great influence on the freezing time. The results of the study can significantly contribute to the development of ice air jet technology.

Porosity forming mechanism and numerical simulation of casting process optimization of nickel-based heat-resistant alloy electrode ingot with large height to diameter ratio

Based on the simulation results of ProCAST software for the filling and solidification process, the formation mechanism of the VIM electrode ingot's pipe and porosities and the influence of the casting process on the formation of electrode shrinkage were studied in detail. The research results indicate that the critical condition for the formation of 200 kg grade C650R heat-resistant alloy is verified to be G/R≤5.0 (K·s)0.5/cm. In addition to the alloy's inherent characteristics, the substantial height to diameter ratio (H/D) of the VIM electrode ingot is the primary factor contributing to the formation of deep pipe and severe porosities. Simply adjusting the casting time or casting speed alone does not significantly improve the solidification quality of the ingot. While the use of a hot top can eliminate pipe, its effectiveness is limited, as the alloy melt at the hot top location has minimal influence on the solidification process in the lower regions of the electrode ingot, thereby failing to effectively reduce the formation of porosities. Properly reducing the casting speed and casting superheat lead to the formation of a V-shaped melt at localized positions during the final stage of solidification. This enhances the ability of the liquid phase for further feeding, ultimately significantly decreasing both the depth of pipe and the porosity rate. The optimal casting process optimization solution for C650R alloy electrode ingot with a size of Φ130 mm × 1240 mm is the casting speed of 60 kg/min and the superheat of 40 °C.

Controllable reinforcement phase distribution at the grain scale via a simple precipitation process

Due to the inability of Zr to refine Al-containing Mg alloys, achieving pronounced grain refinement in cast AZ31 alloy has been a significant challenge for researchers. Surprisingly, we found that the reinforcement phases demonstrated a regular distribution at the grain scale after adding 0.9 wt% Nd and 0.3 wt% Y: Al2RE inside the grains and Al11RE3 agglomerated near the grain boundaries. Additionally, the grain size of AZ31 alloy was significantly reduced from 258 µm to 65 µm. The mechanisms of reinforcement phase distribution and grain refinement were explored through the combination of transmission electron microscope (TEM) and thermal analysis during the solidification process. Al2RE phase precipitates prior to α-Mg, and exhibits a specific orientation relationship with the matrix: 011̅0Mg∥011Al2RE，0002Mg∥22̅2Al2RE. This suggests that Al2RE serves as potentially effective heterogeneous nucleation sites for α-Mg. Moreover, Al11RE3 phase can restrict grain growth in the later stage of solidification. The tensile results show that a regular distribution of the reinforcement phase at the grain scale can not only effectively alleviate stress concentration, but suppress the formation of coarse twins by inducing grain refinement during alloy solidification process, significantly improving the strength and ductility of the alloy.

Experimental investigation of mechanical properties of NiTi superelastic shape memory alloy cables

As a self-centering element in a recoverable functional structure, shape memory alloys (SMAs) usually require a large diameter to provide sufficient bearing capacity, and pre-strain is applied to obtain good self-centering performance and initial stiffness. This study aims to explore the mechanical properties of large-diameter NiTi SMA cables and their potential applications in recoverable functional structures. Through the uniaxial tensile test of 11 SMA cables with 7 × 7 × 1.0 mm, the mechanical properties of SMA cables under different strain amplitudes, cyclic loading effects, loading rates, and different pre-strain modes were evaluated. The results indicate that the energy dissipation capacity of SMA cable increases with the increase of strain amplitude, but at the same time, it will reduce its self-centering capabilities. The equivalent viscous damping ratio decreases after the SMA cable enters the martensitic hardening stage. The residual strain of SMA cable depends on the combined effect of strain amplitude and number of cycles. The larger the strain amplitude and the number of cycles, the more significant the degradation of self-centering performance. After 20 times of constant amplitude loading and unloading, the mechanical properties of SMA cable are relatively stable. The reverse phase transformation stress of the pre-strained SMA cable gradually decreases with the increase of the tensile strain amplitude. The pre-strained SMA cable exhibits a stable restoring force strength in the sub-cycle, and the residual strain is zero. The test results support experimental data for applying large-diameter SMA cables in recoverable functional structures.

Certain investigation on feasibility of developing riser less ductile iron castings

The solidification mechanism of ductile iron is a bit complex due to the precipitation of graphite and silicon. These elements change the solidification pattern of cast iron. Density of these elements is less than iron leads to occupying more volume consequently increase the overall metal volume. There are two aspects on this increase in metal volume. One is, reducing this volume increase to reduce the creation of porosities at the earlier stage of solidification and second is, using this volume increase to remove porosity at the later stage of solidification. Proper understanding of this graphite expansion in cast iron solidification will bring insights on reducing or removing of the risers. The current study focus on correlating the net contraction and austenitic liquidus point with shrinkage. The average contraction found through this study is 1.36 % which is more than the net expansion of 0.25 % (without riser) reported in literature. The study found that properly balancing graphite precipitation, pouring temperature and mold strength can enable riserless casting of ductile iron by compensating for liquid contraction through graphite expansion.

Influence of cooling path on solidification morphology and hot tearing susceptibility of an Al−Cu−Fe−Mg−Si alloy

AbstractIn this work, a numerical approach is applied to study the impact of local cooling conditions on the hot tearing in an aluminium‐copper alloy with iron, magnesium and silicon as impurities. At first, CALPHAD‐coupled multicomponent and multiphase‐field simulations were performed to elucidate the effect of cooling conditions on solidification morphology in the final, critical stage of solidification. Then, the evolution of the melt flow permeability is derived from the simulated three‐dimensional microstructures and discussed in the context of the Rappaz‐Drezet‐Gremaud criterion for hot tearing susceptibility. With increasing cooling rates, the microstructure becomes finer and the resulting permeability first increases and then saturates within the investigated range. It is shown that the Rappaz‐Drezet‐Gremaud hot‐tearing criterion in combination with microstructure simulations responds to different cooling conditions in contrast to a Scheil‐Gulliver based model or an evaluation of the average Kou‐index.