Thermal Shock Cycles Research Articles

Impact of Yttrium Oxide on the Synthesis and Sintering Properties of Cordierite–Mullite Composite Ceramics

To enhance the mechanical properties and high-temperature performance of cordierite–mullite composite ceramics, yttrium oxide (Y2O3), a rare earth metal oxide, was employed as a sintering aid to fabricate these composites via in situ synthesis and non-pressure sintering. This study systematically investigated the formation mechanisms of the cordierite and mullite phases and examined the effects of yttrium oxide on the densification behavior, mechanical properties, volumetric stability, and thermal shock resistance. The results indicate that incorporating yttrium oxide (1.5–6.0 wt%) not only promoted the formation of the cordierite phase but also refined the microstructure and enhanced the thermal shock stability at a sintering temperature of 1350 °C. An optimal addition of 3 wt% yttrium oxide ensures that the primary phases are cordierite and mullite, with a microstructure characterized by uniformly distributed micropores, hexagonal short-columnar cordierite, and interlocking rod-like mullite, thereby significantly improving both the mechanical properties and thermal shock stability. Specifically, the room-temperature compressive strength increased by 121%, the flexural strength increased by 177%, and, after three thermal shock cycles at 1100 °C, the retention rates for compressive and flexural strengths were 87.66% and 71.01%, respectively. This research provides a critical foundation for enhancing the mechanical properties and high-temperature service performance of cordierite–mullite saggers used in lithium battery cathode materials.

Improvement adhesion durability of epoxy adhesive for steel/carbon fiber-reinforced polymer adhesive joint using imidazole-treated halloysite nanotube

Surface treatment is essential for enhancing adhesion durability and minimizing substrate damage in hybrid structural materials. This study focuses on developing a hybrid adhesive lap joint by incorporating halloysite nanotube (HNT) with imidazole-functionalized surfaces (IM-HNT) into epoxy adhesives to improve adhesion performance and thermal shock resistance. The surface treatment of HNT with imidazole (IM) introduced a curing catalyst effect, reducing activation energy by 50% and accelerating curing time by 90%, as confirmed by Kissinger’s plot and permittivity measurements. The optimized IM-HNT content improved thermal stability by controlling thermal expansion and enhanced mechanical properties, achieving a 15% increase in tensile strength and a 50% enhancement in fracture toughness. The adhesion performance of steel/carbon fiber-reinforced polymer (CFRP) hybrid joints was evaluated through single-lap shear tests, demonstrating a 25% improvement in shear strength. Adhesion durability was tested under cyclic thermal shock conditions, showing a 30% increase as IM-HNT content increased. Finite element analysis (FEA) revealed reduced residual stress at the adhesive interface, supporting the enhanced thermal and mechanical robustness. This study highlights the potential of surface-treated halloysite nanotubes in hybrid adhesive lap joints to significantly improve adhesion durability and thermal shock resistance, addressing critical requirements for hybrid structural materials.

Cyclic thermal shock resistance and tribological properties of AlCrSiN, AlTiSiN and AlCrSiN/AlTiSiN multilayer hard coatings

Cyclic thermal shock resistance and tribological properties of AlCrSiN, AlTiSiN and AlCrSiN/AlTiSiN multilayer hard coatings

Thermal shock cycle finite element simulation and optimization design of Yb2Si2O7-based high temperature abradable sealing coatings based on machine learning

Thermal shock cycle finite element simulation and optimization design of Yb2Si2O7-based high temperature abradable sealing coatings based on machine learning

Simulation and Study of Manufacturing of W–Cu Functionally Graded Materials by a Selective Laser Melting Process

Plasma-facing components (PFCs) were simulated by ANSYS, and the influence of gradient layer number and composition distribution index on the distribution of temperature field and stress field was analyzed. The simulation results show that a gradient structure with four gradient layers and a component distribution index of 1 makes the PFC assembly have lower overall temperature and lower thermal stress. Tungsten–copper functionally graded materials (W–Cu FGMs) (W-20 vol% Cu/W-40 vol% Cu/W-60 vol% Cu/W-80 vol% Cu) were fabricated by a selective laser melting (SLM) process based on finite element simulation results. The effects of microstructure on the hardness, internal stresses, thermal conductivity, and thermal expansion coefficient of the W–Cu FGMs were evaluated. The results show that hardness increases from 196 to 1173 HV0.3 with increasing W content. The internal stresses of W-20 vol% Cu, W-40 vol% Cu, W-60 vol% Cu, and W-80 vol% Cu are about 191.7 MPa, 627 MPa, 1049.5 MPa, and 561.9 MPa, respectively. The thermal conductivity of the W–Cu FGM is 23 W/m·K and the thermal diffusion coefficient is 10 mm2/s at 25 °C, and the thermal conductivity rises to 70 W/m·K and the thermal diffusion coefficient rises to 18.5 mm2/s at 800 °C. After 100 thermal shock cycles, the internal defects increased, but the interface between the gradient layers remained well bonded.

Thermal Shock Damage and Failure Mechanism of 2D Laminated SiC/SiC with Barium‐Strontium Aluminosilicate‐Based Environmental Barrier Coating

Thermal shock damage is a key issue for the stable service of SiC/SiC with environmental barrier coating (EBC) in aero‐engines. The thermal shock damage behavior of SiC/SiC with barium‐strontium aluminosilicate (BSAS)‐based EBC in an air atmosphere quenched by air and water media between RT and 1200 °C is systematically investigated. After 600 thermal shock cycles, cracks form in the EBC due to a sharp increase in the internal thermal stresses, and a SiO2 TGO layer is formed on the Si bonding coat. Based on the TGO thickness, damage within BSAS/mullite coatings is quantified by the oxygen permeability (2.541 × 10−11 mol·(atm cm s)−1), which is increased by 2.5 times compared to static oxidation. Despite cracking damage occurring in the SiC matrix of SiC/SiC substrates, the load‐bearing capability of SiC fibers is improved due to the modulus matching of the fiber/matrix. Oxidation damage is dominated the degradation of the performance of SiC/SiC substrates, whose flexural strength is decreased by 15% after 600 cycles. In the thermal shock test quenched by water media, the strength retention of SiC/SiC‐EBC is below 60%, and an increase in internal defects and even delamination of the SiC/SiC substrate are the main reasons for the thermal shock failure of SiC/SiC‐EBC.

Evaluating the Thermal Shock Resistance of SiC-C/CA Composites Through the Cohesive Finite Element Method and Machine Learning

Silicon carbide-coated carbon fiber-reinforced carbon aerogel (SiC-C/CA) composites are ideal for high-temperature applications due to their ability to endure rapid temperature changes without losing structural integrity. However, assessing and optimizing the Thermal Shock Resistance (TSR) of these composites is challenging due to the complexities in measuring thermal and mechanical responses accurately under rapid fluctuations. Herein, we introduce a novel approach combining the cohesive finite element method (CFEM) with machine learning (ML) to address these challenges. The CFEM simulates crack initiation and propagation and captures mechanical behavior under thermal stress, while ML predicts TSR using simulation datasets, reducing the need for empirical trial-and-error processes. Our method achieves a prediction error for coating residual stress within 15.70% to 24.11% before and after thermal shock tests. Additionally, the ML model, developed to predict the average stiffness degradation factor of the SiC coating after three thermal shock cycles, achieves a coefficient of determination (R2) of 0.9171. This combined approach significantly improves the accuracy and efficiency of TSR assessment and can be extended to other coating materials, accelerating the development of high-temperature-resistant materials with optimized TSR for industrial applications.

Crystallographic changes and mechanical Performances of SnAg2.4/Cu Pillars during thermal shocks in a large temperature range

Crystallographic changes and mechanical Performances of SnAg2.4/Cu Pillars during thermal shocks in a large temperature range

The Cr/Cr2N multilayer coating with high load-bearing capacity and thermal shock resistance

The Cr/Cr2N multilayer coating with high load-bearing capacity and thermal shock resistance

Failure behavior study of EB-PVD TBCs under CMAS corrosion and thermal shock cycles

Abstract Calcia-magnesia-alumino-silicate (CMAS) erosion has become a major obstacle, limiting the operating temperature and service life of Thermal barrier coatings (TBCs) in aircraft engines. Constructing simulation environments that replicate TBCs’ working conditions and exploring online, non-destructive detection techniques are reliable approaches to studying coatings’ failure, representing both a global research hotspot and a challenge in this field. The paper presents an initial endeavor to establish a simulation experiment for TBCs in aviation-engine within a CMAS environment. Experimental results show that electron beam physical vapor deposition (EB-PVD) Y2O3-stabilized ZrO2 (YSZ), one of the mainstream TBCs technologies, produced 20% surface spallation after 50 thermal-shock cycles under simulated CMAS corrosion conditions. Testing and analysis of the macroscopic and microscopic structures of the failed samples, combined with SEM, EDS, and XRD findings, revealed significant physical and chemical interactions between the ceramic layer and CMAS deposits, as well as phase transformation within the coatings, leading to substantial alterations in mechanical properties and ultimately causing the failure of EB-PVD YSZ.

Can Chitosan Be Depolymerized by Thermal Shock?

Chitosan is a biopolymer with a wide range of applications. It typically requires depolymerization to achieve a desired molecular weight for specific uses. This study investigated the potential for depolymerizing chitosan by thermal shock and grinding to produce nanochitosan. A series of thermal shock cycles combined with grinding were performed to assess the influence of drying temperature, residence time, and number of thermal cycles on the molecular weight, particle size, and crystallinity of chitosan. The thermal shock reduced the molecular weight and particle size of chitosan within the first hour of treatment, with optimal conditions achieved at a drying temperature of 90 °C and residence time inside the oven of 5 min. These conditions resulted in a molecular weight of 15.0 kDa with an average diameter of 136 nm. Thermal shock can be considered an effective method for chitosan depolymerization with grinding serving to standardize the particle size. This optimized process offers promising applications where low-molecular-weight chitosan is required, including biomedical, agricultural, and food industries, as well as the potential for reducing time and energy consumption.

Study on the Oxidation Behavior of TiB2-CeO2-Modified (Nb,Mo,Cr,W)Si2 Coating on the Surface of Niobium Alloy.

A novel TiB2-CeO2-modified (Nb,Mo,Cr,W)Si2 coating was prepared on a Nb-5W-2Mo-1Zr alloy substrate using two-step slurry sintering and halide-activated pack cementation to address the limitations of a single NbSi2 coating in meeting the service requirements of niobium alloys at elevated temperatures. At 1700 °C, the static oxidation life of the coating exceeded 20 h, thus indicating excellent high-temperature oxidation resistance. This was due to the formation of a TiO2-SiO2-Cr2O3 composite oxide film on the coating surface, which, due to low oxygen permeability, effectively prevented the inward infiltration of oxygen. Additionally, the dense structure of the composite coating further enhanced this protective effect. The composite coating was able to withstand over 1600 thermal shock cycles from room temperature to 1700 °C, and its excellent thermal shock performance could be attributed to the formation of MoSi2, CrSi2, and WSi2 from elements such as Mo, Cr, and W, which were added during modification. In addition to adjusting the difference in thermal expansion coefficients between the layers of composite coatings to reduce the thermal stress generated by thermal shock cycles, the formation of silicide compounds also improved the overall fracture toughness of the coating and thereby improved its thermal shock resistance.

Phase transition heat storage and self-healing mechanism of spinel-calcium aluminate composite aggregate in corundum castable

Phase transition heat storage and self-healing mechanism of spinel-calcium aluminate composite aggregate in corundum castable

Effect of thermal shocks on the interfacial bond strength of sandwich composites built with rigid and soft materials produced through extrusion process

Effect of thermal shocks on the interfacial bond strength of sandwich composites built with rigid and soft materials produced through extrusion process

Crack behaviour and failure mechanisms of air plasma sprayed (Gd, Yb) doped YSZ thermal barrier coatings under oxy-acetylene flame thermal shock

Crack behaviour and failure mechanisms of air plasma sprayed (Gd, Yb) doped YSZ thermal barrier coatings under oxy-acetylene flame thermal shock

Synthesis of low-cost refractory cordierite for solar thermal storage: Characterization of mechanical, thermal and physical stability during thermal shock cycles

Synthesis of low-cost refractory cordierite for solar thermal storage: Characterization of mechanical, thermal and physical stability during thermal shock cycles

Extruded PLA-CF modeled after human DNA: Effects of thermal shock and structural design on tensile and flexural properties

This study used human DNA structure to inspire an innovative design concept. Mechanical testing assessed how design parameters and thermal shock cycles affected it. As thermal shock cycles increase, material characteristics decrease. After sixty thermal shock cycles, tensile and flexural strengths dropped 43.33% and 35.90%, respectively. DNA structures had a better strength-to-weight ratio than solids. After 60 thermal shock cycles, 2 mm ribs, straight ribs, and hexagonal honeycomb ribs had higher tensile and flexural strengths of 9.42 and 20.76 MPa, respectively.

Thermophysical-mechanical behaviors of hot dry granite subjected to thermal shock cycles and dynamic loadings

Thermophysical-mechanical behaviors of hot dry granite subjected to thermal shock cycles and dynamic loadings

Synthesis and thermophysical properties of rare-earth tantalate ZrO2-Dy3TaO7 ceramics

Abstract Thermal Barrier Coatings (TBCs) are of major concern to researchers because of their outstanding properties, such as high-temperature resistance, compressive resistance, hardness, and toughness. Its applications are wide-ranging and critical. Examples include hypersonic vehicles, aero-engines, and service in high-temperature and high-impact extreme environments. This work focuses on the preparation, thermal properties (coefficient of thermal expansion, thermal conductivity), and performance evaluation (thermal shock resistance, thermal shock resistance, and bonding) of ZrO2-Dy3TaO7 rare earth tantalate ceramic coating materials. The results show that ZrO2-Dy3TaO7 possesses a low thermal conductivity (1.25-1.50 W K−1 m−1, 900°C), a high thermal expansion coefficient (10.80-11.14×10-6 K−1, 1200°C), which is about half of the value of the thermal conductivity of 7YSZ (2.8-2.2 W K−1m−1). It is better than that of the 7YSZ (10.04×10−6 K−1, 1200°C), which meets the performance requirements of the new thermal barrier coating. In addition, ZrO2-Dy3TaO7 can achieve more than 6, 000 thermal fatigue cycles at 1200°C, and the ideal number of thermal shock cycles is 4, 040 cycles at the same temperature. These outstanding test results demonstrate that the ceramic coating can effectively protect the substrate material and provide long-term service in high-temperature copper liquid. This research lays the theoretical foundation for the development of next-generation coating materials, particularly for thermal barrier/environmental barrier integrated coating materials.

An advanced ceramifiable organic-inorganic hybrid polysiloxane coating with superior moisture-resistant property

An advanced ceramifiable organic-inorganic hybrid polysiloxane coating with superior moisture-resistant property