Thermal Shock Test Research Articles

A review of thermal shock behavior of ceramics: Fundamental theory, experimental methods, and outlooks

AbstractThe thermal shock resistance of ceramics is a key factor for determining the durability of ceramic components under transient thermal conditions and is also one of the key factors for evaluating the stability of ceramics under extreme thermal conditions. After rapid heating or cooling, the surface and internal thermal stress mismatches of ceramics can cause severe thermal damage. Two main types of ceramic thermal shock exist: rapid cooling and rapid heating thermal shock. This article presents a broad understanding and insight into fundamental theory and experimental methods for ceramic thermal shock testing. The experimental equipment and procedures, test result evaluation, and material characterization of ceramic thermal shock are summarized. Moreover, outlooks and perspectives are discussed for testing and characterizing ceramic thermal shock resistance. This review will be helpful to researchers performing studies in the relevant fields of ceramics.

Thermal shock resistance of WC–Cr3C2–Ni coatings deposited via high-velocity air fuel spraying

In this study, the high-velocity air fuel (HVAF) spraying technique was used to deposit WC–Cr3C2–Ni wear-resistant coatings on the surface of crystallization rollers to overcome the wear problem of the substrate of thin-strip continuous-casting crystallization rollers and thus improve their efficiency. The performance and durability of the WC–Cr3C2–Ni coatings on the surface of the roller body during the actual continuous casting process were investigated by performing thermal shock tests. It was found that the thermal shock resistance of the closed-curved surface coatings increased with their thickness. The coatings exhibited the best thermal shock resistance at a thickness of 300 μm, and the number of cycles they could withstand at 800 °C reached 15. The results of the high-temperature wear tests showed that the WC–Cr3C2–Ni coatings deposited on the surface of the crystallization roller via HVAF reduced the friction coefficient of the surface of the roller body (from 0.425 to 0.362), and greatly reduced the wear loss volume during the wear process (reduced by 83 %). The WC-Cr3C2-Ni coating showed excellent resistance to crack initiation and propagation during wear and can be stabilized in long-cycle production and protect the substrate of the crystallization roller effectively. This study provides a theoretical basis for the selection and preparation of surface coatings for thin-strip continuous-casting crystallization rollers.

Structure and properties of the hot pressing molded anodized aluminum alloy/polyformaldehyde hybrids

The metal-plastic hybrid is one of the important solutions for lightweight and high-strength composite. The anodized aluminum alloy（AAA）/polyformaldehyde（POM） hybrids with excellent mechanical properties were processed by the hot pressing technology. The surface of the aluminum alloy plate was firstly pretreated with phosphoric acid and oxalic acid anodizing, resulting in a large number of micro-nano scale pores on the surface. These pores were well embedded with plastic melt during hot pressing to form micro-nano mechanical interlocking structures and the Al–O–C chemical bond at the interface is generated, thus ensuring good bonding strength at the metal and plastic interface. The maximum tensile-shear strength of the metal-plastic hybrid was 30.65 MPa, meanwhile, the metal-plastic interface failure presented mainly a mixed failure mode, including resin removal from the metal surface and plastic tearing from the plastic surface. At the same time, the salt spray test, thermal shock test, and variable temperature test were adopted to investigate the application performance of the metal-plastic hybrid. The Al/POM hybrids were able to maintain their mechanical strength above 20 MPa for 28 days in a salt spray environment, 14 times in a thermal shock cycle, and at high temperatures. The high mechanical strength of hybrid has good potential for automotive applications.

Low-cost iron (Fe) hollow fiber membrane for hydrogen separation

Dense metal membranes are widely studied due to their promising performance in hydrogen separation. In this work, the low-cost dense iron (Fe) hollow fiber membranes (FeHFMs) were developed via the phase inversion and high-temperature sintering method. By tuning the preparation conditions, two typical gas-tight hollow fibers referred to as the sandwich- and honeycomb-structured membranes were successfully synthesized. H2 permeation behavior was well described by Sieverts equation based on the solution-diffusion mechanism. The sandwich-structured FeHFMs had an H2 flux of up to 7.51 mmol m−2 s−1 when operated at a temperature of 850 °C. In comparison, the honeycomb-structured FeHFMs further enhanced the H2 flux by a factor of 3.2 due to the optimized membrane morphology with only one single dense iron layer. The developed FeHFMs showed superior H2 permeation stability in thermal shock tests (40 h) and long-term stability tests (120 h). This work also expanded the potential application horizons of the FeHFMs, which can be easily tailored into porous or dense structures by tuning the sintering conditions.

The Influence of Cyclic Thermal Shocks at High Temperatures on the Microstructure, Hardness and Thermal Diffusivity of the Rene 41 Alloy.

The precipitation-hardenable nickel-based superalloy Rene 41 exhibits remarkable mechanical characteristics and high corrosion resistance at high temperatures, properties that allow it to be used in high-end applications. This research paper presents findings on the influence of thermal shocks on its microstructure, hardness, and thermal diffusivity at temperatures between 700 and 1000 °C. Solar energy was used for cyclic thermal shock tests. The samples were characterized using microhardness measurements, optical microscopic analysis, scanning electron microscopy coupled with EDS elemental chemical analysis, X-ray diffraction, and flash thermal diffusivity measurements. Structural transformations and the variation of properties were observed with an increase in the number of shocks applied at the same temperature and with temperature variation for the same number of thermal shocks.

Development of Ag@Si composite sinter joining with ultra-high resistance to thermal shock test for SiC power device: Experiment validation and numerical simulation

Owing to its cost-effectiveness and low coefficient of thermal expansion (CTE), micron Si is incorporated into sintered Ag matrix to develop an Ag@Si composite sintering strategy. The Si integration helps reduce cost and alleviate CTE-mismatch of Ag-sintered die attachments. An innovative Ag@Si composite sintering structure is achieved by low-temperature and pressure-less sintering process, where a possibly slight diffusion of native SiO2 on the Si surface toward Ag is indicated by TEM observation, enabling the integration of Ag and Si into one continuous network. Owing to the robust well-bonded composite sintering, the Ag@Si joining strategy provides mechanical/microstructural reliability far beyond the pure Ag sinter joining, demonstrating significant prospects in high-temperature interconnection applications. During the harsh thermal cycling (−50–250 °C), the mitigating effect of the Si addition on CTE mismatch is manifested through the substantial suppression of microstructure deterioration in Ag@Si joint that occurs in pure-Ag-sintered joint, while the shear strength retention rate is doubled. Detailed investigation into the mechanism for elevated performance was conducted by material property and Missies stress analysis. The incorporation of Si helps modify the CTE, elastic properties, and stress distribution of Ag@Si-sintered material, synergistically contributing to the satisfactory joining reliability.

Effect of critical plasma spraying parameters on mechanical properties of a novel high-entropy (Y0.2Yb0.2Sc0.2Gd0.2Lu0.2)2Si2O7 environmental barrier coating

The aim is to investigate the effect of critical plasma spraying parameter (CPSP) on the mechanical properties and thermal shock resistance of a novel (Y0.2Yb0.2Sc0.2Gd0.2Lu0.2)2Si2O7 high-entropy environmental barrier coating prepared by plasma spraying. Based on a modified Vickers indentation method, the residual stress and fracture toughness of coatings were evaluated, and then the relationship between the CPSP value and thermal shock lifetime of coatings was also established. As a result, the residual compressive stress of (Y0.2Yb0.2Sc0.2Gd0.2Lu0.2)2Si2O7 coating is reduced from -(53.24 ± 6.78) MPa to -(17.97 ± 3.04) MPa with the CPSP value decreases from 1.17kW/Lpm to 0.94kW/Lpm, while the corresponding fracture toughness exhibits an increasing tendency. The combination of higher fracture toughness and lower residual stress result in better thermal shock resistance for the coating, and the longest thermal shock lifetime of (136 ± 16) cycles for the coating deposited with a CPSP value of 0.94kW/Lpm is obtained during thermal shock test at 1350 °C.

Infrared Radiation-Assisted Non-Pressure Sintering of Micron-Sized Silver for Power Electronic Packaging

In recent years, silver sintering has gained increasing attention in high-power density electronic packaging due to its characteristics such as a high melting point and excellent thermal and electrical conductivity. Micron-sized silver sintering offers a lower cost, but requires a longer processing time and additional pressure, which constrains its application. This paper presents a low-cost sintering process using infrared radiation (IR) as a heat source. By leveraging the unique properties of IR, the process achieves selective heating. The thermal energy can be mainly absorbed by the specific areas requiring sintering. This innovative approach eliminates the need for external pressure during the sintering process. This feature not only simplifies the overall process but also reduces the processing time required for sintering. The silver joints obtained from IR sintering process for 45 min achieved an average chip shear strength of 38 MPa at a temperature of 225 °C, which is higher than the strength of silver joints obtained from a traditional sintering process for 2 h. Additionally, the IR-sintered silver joints have a resistivity of 9.83 × 10−5 Ω·cm and scanning electron microscope (SEM) images of the joints reveal that the sintered joints obtained through the IR sintering process exhibit less porosity compared to joints obtained through a traditional sintering process. The porosity of the IR silver joints at 225 °C is 6.4% and does not change even after 3000 cycles of thermal shock testing, showing outstanding reliability. A GaN power device using IR silver joint also performed better in thermal and electrical performance testing, showing promising potential for the application of micro-silver paste in power electronic devices.

Isothermal Oxidation and Thermal Shock Resistance of Thick and Porous LaMgAl11O19 Abradable Topcoat

An exploration of the plasma-sprayed abradable sealing coatings (ASCs) of a thick and porous LaMgAl11O19 topcoat onto SiC/SiC ceramic matrix composites (CMCs) is detailed in this study. Interlayers comprising Si/Si + Yb2Si2O7/Yb2SiO5 environmental barrier coatings (EBCs) were strategically employed, considering their function in protecting the SiC/SiC CMCs from recession and mitigating thermal expansivity misfit. An isothermal oxidation test was conducted at 1300 °C and resulted in the formation of bubble and glassy melt on the side surface of the coated sample, while a significant reaction layer emerged at the Yb2SiO5/LaMgAl11O19 interface near the edge. The localized temperature rise caused by the exothermic oxidation of the SiC/SiC substrate was determined to be the underlying factor for bubble generation. The temperature-dependent viscosity of the melt contributed to various bubble characteristics, and due to the enrichment of Al ions, the glassy melt exacerbated the degradation of the Yb2SiO5 layer. After a thermal shock test at 1300 °C, the substrate on the uncoated backside of the sample experienced fracture, while the front coating remained intact. However, due to the presence of a through-coating crack, an internal crack network also developed within the substrate.

Development of electroforming technology for flexible metal substrates for high-efficiency double-sided electronic devices

In this study, we investigate a novel material that surpasses conventional concepts used for substrate materials in flexible electronic devices. Unlike traditional materials, this novel material can replace polymers with a metallic substance. This substance is capable of supporting electronic devices on both sides. Our development focuses on a metallic substrate material based on Fe-Ni. This material allows for the implementation of secondary batteries on its extremely flat opposite side through the electroforming method. The Fe (Iron)-Ni (Nickel) material produced by electroforming shows superior characteristics in terms of coefficient of thermal expansion (CTE) and mechanical properties. This superiority is due to its finer grain size, compared to Fe-Ni produced by the rolling process. Furthermore, when we use the Fe-Ni material to manufacture secondary batteries, it demonstrates equivalent or superior battery characteristics compared to the conventional aluminum (Al) collector material. During thermal shock tests, the Fe-Ni material also shows superior adhesion compared to the traditional Al collector. This advantage is attributed to Fe-Ni's low CTE. Our approach enables the implementation of secondary batteries for power generation on one side and the manufacture of electronic components for power consumption on the other. This creates a new concept for flexible substrate materials.

The influence of sodium silicate water glass content on the structure and properties of silicate thermal insulation coating

Thermal insulation slurry was fabricated using sodium silicate water glass (SSWG) as the film-forming material and hollow glass microspheres (HGM) as thermal insulation fillers. The thermal insulation slurry was coated on 316L stainless steel to fabricate a silicate thermal insulation coating. The results show that SiO2 phase is formed by SSWG in the thermal insulation coating after sintering at 680 ℃. Through polymerization and dehydration reactions between Si-OH groups, the Si-O three-dimensional network structure develops at 680 ℃. The optimal value of SSWG to aggregate mass ratios is 2.00. Under this condition, the silicate thermal insulation coating exhibitssmoothsurface, continuous and dense microstructure, high Shore hardness of50.1 HSD,remarkablethermal insulation efficiency of21 %at260 ℃, andexcellentresistance to drop and thermal shock tests without anynoticeablecracks or detachment.

On the Thermal Shock Resistance and Failure Mechanism of the Pt-Modified Aluminide Bond Coating

The failure mechanism of the Pt-modified aluminide (Pt-Al) bond coating (β-(Ni, Pt)Al coating) in a simulated service environment has seldom been investigated. Based on a self-developed thermal barrier coating service environment simulator, a thermal shock experiment of single-phase Pt-Al bond coating on DD419 substrate at a temperature of 1170 °C was conducted combined with a real-time monitoring infrared thermal imager. The lifespan and failure mechanism of the coating are analyzed in detail. The results reveal that specimens of the Pt-Al bond coating, subjected to three repeated tests, exhibit failure after 650, 528, and 793 thermal shock cycles at 1170 °C, respectively. After failure, the contents of Pt and Al elements in the peeled region are lower than those in the unpeeled area, and a diffusion zone emerges in the bond coating. The failure mechanism of the Pt-Al bond coating during the thermal shock test can be attributed to three main aspects: (1) the diffusion and consumption of the Pt element reduced the oxidation resistance of the Pt-Al bond coating; (2) the diffusion and depletion of elemental Al causes a phase change in the coating, leading to the failure of the coating; (3) thermal stresses are generated in the Pt-Al bonded coating during the thermal shock test, which ultimately leads to wrinkling.

Improvement of Bonding Strength and Thermal Shock Reliability for Ag Sinter Joining Direct on Al Substrate

Ag sinter paste joining as a proven die bonding technology have been used in the electric vehicle. However, for the Ag sinter paste joining, metallization layers on substrate are usually necessary such as Ni-P/Au or Ni-P/Ag to get a good bonding quality. The direct bonding on DBC (direct bonded copper) or DBA (Direct Bonded Aluminum) substrates without metallization layers are very attractive. In this study, we investigated the direct bonding on an aluminum (Al) substrate by Ag sinter paste and propose an abrasive blasting processes to treat the Al surface to increase the initial bonding quality. The result show that the shear strength of SiC/Al joint structure by Ag sinter paste can be improved by treating the Al surface. The shear strength of joint structure without surface treatment increased from 26.9 MPa to 32.2 MPa for a strong blasting treatment on Al surface. In addition, the results of thermal shock test (-40 ℃~150℃) also show that the blasting treatment on Al surface can improve the shear strength and reliability of SiC/Al joint structure.

Solder joints on thick printed copper substrates

This article addresses the soldering of larger components onto ceramic substrates with thick printed copper patterns with a reduced amount of flux or using glutaric acid as a flux substitute. The main goal of the research was to create high quality connections by soldering on ceramic substrates, together with elimination of conventional flux from the process, and also to study the reliability of soldered joints on ceramic substrates under thermal shock ageing. The mock-up chips were used in the test and for this reason the test was primarily focused on bottom joint in the structure or sandwich structures. In the experiment, vacuum soldering using formic acid vapors to reduce oxides was used. Then all samples were observed under X-RAY radiation and selected samples were submitted for thermal shock testing (-40°C / 125°C / 1000 cycles). After the shock testing, another X-RAY scan with void area measurement and shear strength testing were realized. The results showed that our contacting soldering processes on ceramic substrates (with diluted flux or glutaric acid) are applicable and the selected samples also endures the shock ageing, especially bottom joint between ceramic substrate with Cu layer and solder alloy. The results also showed that void area and mechanical shear strength of soldered ceramic samples created with diluted flux or glutaric acid are relatively comparable with standard samples (FR-4).

Study of thermal shock and chemical durability of a porcelain formulated from local raw materials from Burkina Faso

This work evaluates the resistance to chemical attack and thermal shock of porcelain formulated from local raw materials from Burkina Faso for their validation in real use. A kaolinitic clay, a pegmatite and sand were used for the formulation of porcelain tiles. Some samples were shaped by casting into porous molds and sintered at a temperature of 1240 °C. The average heating rate is 10 °C/min up to the final given temperature. These porcelains were immersed to a depth of 25 mm in test solutions and kept closed at 20 °C for 12 days. Six concentrations of test solutions were prepared to perform these tests: ammonium chloride (100 g/L); hydrochloric acid (3% and 18% by volume); lactic acid (5% by volume); citric acid (100 g/L) and alkali KOH (30 g/L and 100 g/L). The test showed that these porcelains are resistant to chemical attacks with insignificant mass variations ranging from −0.030 to 0.053 wt%. The results of the thermal shock test show that formulated porcelains are resistant to the brutal variation of temperature. The results obtained qualify the porcelains for industrial and real use.

A new strategy for improving TBCs performance through tailoring the bond coating interface with laser texturing

The parallel micro-hole texture was manufactured to tailor the bond coating interface morphology by a one-step process with the assistance of nanosecond pulsed laser technique. It is demonstrated that the interface stability of the laser-textured TBCs was improved through the evaluation of high-temperature isothermal oxidation under different durations and water-quenching thermal shock at 1050 ℃. The interfacial TGOs formed in the laser-textured TBCs were composed of the continuous alumina strip and grew more slowly compared to that of the as-sprayed TBCs during isothermal oxidation. In addition, as for the laser-textured TBCs, no transverse cracking was noticed along the TGOs interface and the alumina-only TGOs developed a thickness of approximately 1.4 µm after thermal shock testing. The high surface density of micro holes on the bond coating interface enhanced the interfacial toughness and suppressed TGOs growth, which contributed to improving the TBCs durability.

Advanced Analysis of the Properties of Solid-Wire Electric Contacts Produced by Ultrasonic Welding and Soldering.

The current article presents an advanced analysis of the properties of solid-wire electric contacts produced with ultrasonic welding and soldering. Soldering is generally used to join thin, solid copper wires to produce electrical contacts in small-volume production, as ultrasonic welding does not provide acceptable peel force and tensile strength due to the deformation and thinning of the wires. In this article, ultrasonic welding of thin, solid copper wires using a ring before and after a thermal shock test is discussed and compared with the standard soldering technique. The thermal shock test was carried out in the temperature range from -30 to 150 °C. Half of the samples, for both the joining techniques and the wires, were subjected to the thermal shock test; the other half were not. Investigations included electrical resistance tests, optical and SEM microscopy, XRD, microhardness measurements, peel tests, tensile tests, and fractographic analysis. The electrical resistance test, microscopy, microhardness measurements, and fracture examinations showed no differences between the thermal shock-exposed and the non-exposed samples with the same joining process. In mechanical tests, the ultrasonic joint demonstrated superior strength compared to the soldered joint.

Fabrication, sintering behavior and mechanical properties of calcium oxide doped yttrium oxide refractory via aqueous gel casting method

Yttrium oxide is an ideal choice for titanium aluminum alloy melting and casting, its wider use is hindered by sintering challenges and low thermal shock resistance. To address this, we propose a gel casting method for calcium oxide-doped yttrium oxide production. We pretreated yttrium oxide with phosphoric acid to prevented hydrolysis and adjusted the isoelectric point of yttrium oxide to match calcium carbonate's. Anions from calcium carbonate increased slurry solid content (up to 58 vol%) while maintaining low viscosity (57.78 mPa·s at 40 s−1 shear rate). After sintering at 1650 °C for 2 h, the material showed a flexural strength of 78 MPa, with a 90% retention rate after thermal shock test. The introduction of calcium oxide induced lattice distortion, improving mechanical properties by aiding sintering and grain boundary diffusion. XPS and STEM analysis confirmed random replacement of Y3+ by Ca2+ at the C2 position with 1 wt% doping.

Environmental tests and reliability characterization of pixel-sized colloidal QDs for next-generation display technologies

This study investigates integrating pixelated colloidal quantum dot (QD) layers into LCDs to enhance color conversion and pixel-level enrichment for future display technologies. We developed miniature prototypes with pixel-sized QD color-converter layers seamlessly integrated into the backlight unit (BLU). The prototypes, featuring red- and green-emitting QD pixels with a single blue LED on glass substrates, underwent rigorous environmental tests such as Thermal Shock Test (TST), Thermal Cycle Test (TCT), High Temperature High Humidity Test (HHT), and Low Temperature Test (LTT). The assessment covered the uniformity of light, spectral radiance, and CIE color coordinates, revealing insights into the performance of the QD layers through the analysis of pre- and post-environmental tests. Despite a decrease in luminance, the QD layers exhibited resilience against rapid temperature variations, enduring thermal shock, and thermal cycle tests without cracking. However, high-temperature and high-humidity conditions revealed susceptibility. Low-temperature stress tests demonstrated stable color gamut coordinates with no discernible shifts. This research fills a notable gap in the existing literature by conducting comprehensive environmental tests on pixel-sized QD utilization in display technologies, providing valuable insights to enhance the stability, durability, and reliability of QD displays.

Effects of various fillers on the thermal shock and fouling resistance characteristics of zirconia-based composite coatings for high-temperature applications

Composite coating technology has been extensively developed to meet industrial demands for coatings with specifications that exceed the capabilities of conventional coating technologies and that can function in extreme environments and high temperatures. The composite coating in this study is focused on materials that have hydrophobicity. To achieve this hydrophobicity, the coating must have at least one restrictive property: antifouling. In this research, antifouling coating materials based on certain zirconia ceramic composites (ZrO2) and fillers, such as boron nitride, MoS2, and graphite, are chosen. The substrate used is a low-carbon steel, which is used in high-temperature power plants. The slurry spray coating method is chosen, which is a simple and low-cost method. Thermal shock and fouling resistance tests are conducted, and the samples are further observed with Scanning Electron Microscopy-Energy-Dispersive X-ray Spectroscopy (SEM-EDS). The results show that the higher the hBN filler content in the zirconia composite coating is, the better the thermal shock and antifouling resistance levels. This phenomenon is indicated by the lower delamination of the coating after the thermal shock treatment and the lower fouling of sodium sulfate deposits on the surface of the coating after the antifouling treatment than before. The same result is shown by the zirconia composite coating with hybrid filler (hBN-MoS2-Graphite).