Effect Of Cooling Rate Research Articles

Numerical Analysis to Evaluate the Effect of Cooling Rates on Microstructures in Casted Cu-Ni-Si Alloys by Phase-Field Simulation

Numerical Analysis to Evaluate the Effect of Cooling Rates on Microstructures in Casted Cu-Ni-Si Alloys by Phase-Field Simulation

Effect of Cooling Rate on Properties of Beeswax and Stearic Acid Oleogel Based on Rice Bran Oil and Sesame Oil.

This study aimed to investigate how varying cooling rate impacts the characteristics of oleogels prepared using a sesame oil and rice bran oil blend (5:6, w/w) using a combination of beeswax and stearic acid (3:1, w/w at 12%, w/w) as the oleogelators. The study assessed three different cooling rates-0.5, 1.5, and 5 °C/min-with a focus on the attributes of the oleogels. The study revealed that the cooling rate had a substantial impact on the strength of the gel network. The cooling rate of 0.5 °C/min resulted in a higher oil-binding capacity and a stronger gel structure than fast cooling. The thermal properties and molecular interactions of the oleogels were not influenced by the cooling rate. The findings of this study indicated that the characteristics of beeswax and stearic acid oleogel prepared using sesame oil and rice bran oil blend could be tailored by manipulating the cooling rate.

The Effect of Cooling Rate on Solidification Characteristics and Grain Structure of Al-9Si Cast Alloy

A thermal analysis study is essential before the semisolid metal processing of a particular alloy. The surrounding environment, especially the cooling rate is also an important factor. This study investigated the influence of different cooling rates on the solidification characteristics and microstructure evolution of the Al-9Si cast alloy. Four cooling mediums were designed, and their cooling rates are 0.16 ℃/s, 1.0 ℃/s, 1.3 ℃/s, and 1.9 ℃/s, respectively. The results show that the primary dendrite size of the Al-9Si alloy was reduced from 162.61 μm to 86.86 μm as the cooling rate increased from 0.16 ℃/s to 1.9 ℃/s. Significant grain refinement was observed, however, the external cooling has a negligible impact on solid fraction. The optimal temperature range of the Al-9Si cast alloy for the semisolid metal processing at a solid fraction of 0.5 to 0.7 is between 554 ℃ and 563 ℃. With these thermal profiles provided, the relationship between the solid fraction and the solidification time could be expressed using the polynomial equation, which is also useful for point prediction in the subsequent semisolid metal processing.

Cooling rate effects on microstructure and diffusion behaviour in Ti65 alloy: Insights from a modified diffusion model

In the continuous cooling process, the growth of the equiaxed α-phase grains in near-α high-temperature titanium alloys is controlled by the diffusion of alloying elements. Establishing a specific connection between the cooling rate and the diffusion behaviour of alloying elements aids in the precise prediction of the evolution of equiaxed α-phase grain size. This study meticulously controlled the cooling rate during the two-phase region annealing treatment of the Ti65 alloy. Using EPMA technology, the diffusion behaviour of solute elements during cooling was accurately characterized. The study found that slowing the cooling rate promotes the coarsening of the lamellar secondary α-phase grains and the growth of the primary equiaxed α-phase grains. At higher annealing temperatures, the growth of equiaxed α-phase grains can occur at faster cooling rates, while coarse lamellar secondary α-phase grains can be retained at slower cooling rates. The diffusion behaviour of solute elements Al, Ta, Mo, and W between the α-phase and transformed β-phase matrix is significantly influenced by the cooling rate, thus they are considered as the controlling elements for the growth of the equiaxed α-phase grains. Based on the diffusion behaviours of these controlling elements, their single-element diffusion models were categorized and integrated for predicting the grain size of the equiaxed α-phase. The predictions from the revised diffusion model show an excellent agreement with the actual results, with an error margin of about 5%.

Effect of CuO Nanostructure Addition and Cooling Rate on the Microstructure and Mechanical Characteristics of Hypoeutectic Al-2wt.%Si Alloy

Effect of CuO Nanostructure Addition and Cooling Rate on the Microstructure and Mechanical Characteristics of Hypoeutectic Al-2wt.%Si Alloy

Effect of Cooling Rate on Inclusions, Primary Carbides, and Microstructure in Rare-Earth H13 Steel

Effect of Cooling Rate on Inclusions, Primary Carbides, and Microstructure in Rare-Earth H13 Steel

Effects of Cooling Rate and Ti Content on the Solidification Characteristics of Al-Ti Alloys

Effects of Cooling Rate and Ti Content on the Solidification Characteristics of Al-Ti Alloys

Unveiling the Effect of Cooling Rate on Grown-in Defects Concentration in Polycrystalline Perovskite Films for Solar Cells with Improved Stability.

Numerous efforts are devoted to reducing the defects at perovskite surface and/or grain boundary; however, the grown-in defects inside grain is rarely studied. Here, the influence of cooling rate on the point defects concentration in polycrystalline perovskite film during heat treatment processing is investigated. With the combination of theoretical and experimental studies, this work reveals that the supersaturated point defects in perovskite films generate during the cooling process and its concentration improves as the cooling rate increases. The supersaturated point defects can be minimized through slowing the cooling rate. As a result, the optimized FAPbI3 polycrystalline films achieve a superior carrier lifetime of up to 12.6 µs and improved stability. The champion device delivers a 25.47% PCE (certified 24.7%) and retain 90% of their initial value after >1100 h of operation at the maximum power point. These results provide a fundamental understanding of the mechanisms of grown-in defects formation in polycrystalline perovskite film.

A Review on Effect of Cooling Rate on Metallurgical, Mechanical, Geometrical Characteristics and Defects of Laser Cladding Process

A Review on Effect of Cooling Rate on Metallurgical, Mechanical, Geometrical Characteristics and Defects of Laser Cladding Process

Effect of Cooling Rate on Dynamic Magnetic Hysteresis Loop Behaviors of Magnetic Materials by Using as a Model Mixed Spin (1, 3/2) Ising System Under an Oscillating Magnetic Field

Effect of Cooling Rate on Dynamic Magnetic Hysteresis Loop Behaviors of Magnetic Materials by Using as a Model Mixed Spin (1, 3/2) Ising System Under an Oscillating Magnetic Field

Modeling solidification cracking: A new perspective on solid bridge fracture

Solidification cracking is a longstanding and serious problem in metallurgical engineering that is encountered during casting, welding, and additive manufacturing. Extensive research has been conducted on the cracking susceptibility associated with solidification paths, microstructural effects, and thermal conditions, but it remains highly challenging to precisely predict and evaluate the solidification cracking, especially the solid bridging phenomenon and grain size dependence. In this study, a new theoretical model based on solid bridge fracture is proposed for modeling solidification cracking. The occurrence of cracking depends on competition between thermal stress accumulation and solid-bridge strength development, which is fundamentally distinct from existing models in which the cracking depends on liquid feeding. A crack-like structure is utilized to determine the thermal stress at a dendrite root, and demonstrates the absence of stress singularity in a solidifying crack. Grain features are incorporated to show that grain refinement effectively inhibits cracking by lowering the rate of accumulation of thermal stress. In this sense, the cracking susceptibility can be quantified based on grain size distributions. Numerical analyses of binary aluminum alloys validate the proposed model and provide a rational interpretation of reported experimental results in terms of cracking susceptibility, grain size effects, and cooling rate effects. This study presents and validates one of the first solid-bridge fracture-based solidification cracking models, and thus provides a new perspective to support investigation of solidification cracking.

Effect of Cooling Rate on Microstructure and Mechanical Properties According to Heat Treatment Temperature of Inconel 625

Inconel 625 is typically used in extreme environments due to excellent mechanical properties such as high strength, corrosion resistance, abrasion resistance and low-temperature toughness. When manufacturing a hot forged flange with a thick and complex shape, the cooling rate varies depending on the location due to the difference in thermal gradient during the cooling process after hot forging. In this study, to evaluate the microstructure and mechanical properties of Inconel 625 according to the cooling rate, we performed heat treatment at 950°C, 1050°C, and 1150°C for 4 hours followed by water cooling. Additionally, temperature data for each location on the flange were obtained using finite element method (FEM) simulation for each heat treatment temperature, revealing a discrepancy in the cooling rate between the surface and the center. Therefore, the correlation between microstructure and mechanical properties according to cooling rate was investigated.

Effects of Composition and Cooling Rate on Mechanical Properties of Pb-Sb-Sn-As Grid Alloys

The effects of chemical composition and cooling rate on the mechanical properties of Pb–Sb–Sn–As grid alloys for lead-acid batteries were investigated. Mechanical properties were characterized in terms of ultimate tensile strength and elongation at room temperature. Composition and cooling rate of the studied alloys should ensure the increase in the amount of Sn soluble in α-Pb and the decrease in the amount of brittle arsenic precipitates or eutectic β-Sb phase in the structure.

Effect of Cooling Rate on the Microstructure and Mechanical Property of Nickel-Based Superalloy MAR-M247.

Heat treatment is an important process for optimizing the microstructures of superalloys, and the cooling rate after solid solution treatment is one of the most critical parameters. In this work, we treated solid solution MAR-M247 alloys with water quenching, air cooling, and furnace cooling. Microstructure characterization, hardness, and room temperature tensile tests were conducted to investigate the effect of cooling rate on the microstructure and mechanical properties of MAR-M247 alloys. The results showed that the cooling rate after solid solution treatment mainly affected the precipitation behavior of the secondary γ' phase, but it had few effects on other microstructure characterizations, including grain size, γ/γ' eutectic, and MC carbide. The water-quenched sample had the highest cooling rate (400 °C/s) and hardness (400 HV) but suffered from premature fracture because of quenching cracks. A further decrease in cooling rate from 1.5 °C/s to 0.1 °C/s deteriorated hardness (384 HV to 364 HV) and yield strength (960 MPa to 771 MPa) but increased elongation (8.5% to 13.5%). Moreover, the deformation mechanism was transformed from dislocation shearing to Orowan bypassing. The decreased yield strength was mainly due to the weakened precipitation strengthening resulting from γ'-phase coarsening. The improved elongation was attributed to not only the higher work-hardening index caused by interface dislocation networks but also the more uniform deformation, which delayed necking.

Effect of Cooling Rate on Microstructure of In Situ TiC-Reinforced Composite Surface Layers Synthesized on Ductile Cast Iron by Laser Alloying.

The microstructure of the in situ TiC-reinforced composite surface layers developed during laser surface alloying of a ductile cast iron substrate with titanium was related to the solidification conditions in the molten pool. The solidification conditions were estimated using infrared thermography. It was found that the cooling rates of the melt up to about 700 °C/s enable the complete reaction between carbon and the entire amount of titanium introduced into the molten pool. In turn, the cooling rate of about 280 °C/s for the melt containing 8.0 wt% Ti allows the TiC particles to grow in the dendritic form with well-developed secondary arms and a total size of up to 30 µm. For a constant Ti content, the cooling rate of the melt had no effect on the TiC fraction. The increase in the cooling rate elevated the retained austenite fraction in the matrix material, lowering its hardness.

Effect of Cooling Rate on Powder Characteristics and Microstructural Evolution of Gas Atomized β-Solidifying γ-TiAl Alloy Powder

Effect of Cooling Rate on Powder Characteristics and Microstructural Evolution of Gas Atomized β-Solidifying γ-TiAl Alloy Powder

Effect of Cooling Rate on Structural, Corrosion, and Mechanical Properties of Cobalt–Chromium–Molybdenum Dental Alloys

Effect of Cooling Rate on Structural, Corrosion, and Mechanical Properties of Cobalt–Chromium–Molybdenum Dental Alloys

Effect of Cooling Rate on Microstructure, Shape Memory Effect and Mechanical Properties of Cu–13Al–5Fe High-Temperature Shape Memory Alloy Fabricated by Laser Powder Bed Fusion

Effect of Cooling Rate on Microstructure, Shape Memory Effect and Mechanical Properties of Cu–13Al–5Fe High-Temperature Shape Memory Alloy Fabricated by Laser Powder Bed Fusion

Effects of Different Heating and Cooling Rates during Solution Treatment on Microstructure and Properties of AA7050 Alloy Wires.

In the present study, the effects of varying heating and cooling rates during the solution treatment process on the microstructure and properties of AA7050 alloy wires were investigated using tensile tests, metallographic microscopy, electron backscattered diffraction, and transmission electron microscopy. It was found that the recrystallized grain size of the alloy, subjected to method of rapid heating, exhibited a smaller and more uniform distribution in comparison to method of slow heating. The low density of η' strengthening phases after the artificial aging treatment was formed using air cooling method. Meanwhile, by using the water quenching method sufficient solute atoms and more nucleation sites were provided resulting in a large number of η' strengthening phases being formed. In addition, the alloy processed using the water quenching method displayed higher strength than that treated using the air cooling method for the T6 and T73 states. Furthermore, coarse precipitates formed and less clusters were observed in the matrix, while high density nanoscale clusters and no continuous precipitation are formed when using the water quenching method.

Effect of Cooling Rate on Microstructure, Phases, and Properties of Al-Si Coated Hot-Press-Forming Steel Sheets

Effect of Cooling Rate on Microstructure, Phases, and Properties of Al-Si Coated Hot-Press-Forming Steel Sheets