Pressureless Sintering Method Research Articles

How does cold sintering affect the microstructural evolution of high-entropy pyrochlore during pressureless sintering?

The challenge of producing dense fine-grained high-entropy ceramics is hereby addressed by a combined cold and conventional pressureless sintering method for the first time. It provides nearly fully dense high-entropy pyrochlores with better microstructural homogeneity, and only half the grain size of conventional pressurelessly sintered samples with identical density. Both the finer and more homogeneous microstructures benefit better mechanical properties in hardness and reduced Young’s modulus. The kinetics and activation energies of both densification and grain growth were quantified and discussed to understand how cold sintering affects the microstructural evolution during the following pressureless sintering. More importantly, cathodoluminescence analysis suggested that cold sintering could cause more defects on the surface of the original particles, which could promote the grain boundary diffusion and have drag effects on grain boundary motion. The lessons learned here offer scientific understanding and technological guidance towards pressureless sintering of dense bulk high-entropy ceramics.

Preparation of transparent AlON ceramics with controlled shapes by a novel spontaneous coagulation casting and pressureless sintering method

Aluminum oxynitride (AlON) exhibits excellent mechanical properties and good optical transparency in the ultraviolet to near-infrared range and can be used in military and civilian fields. However, the troublesome molding of AlON, especially for complex shapes, limits its promotion and application. Therefore, transparent AlON ceramics with complex morphologies were prepared for the first time by a novel spontaneous coagulation casting (SCC) and pressureless sintering method. In this study, we report a simple carbothermal reduction and nitridation (CRN) method for synthesizing high-purity AlON powder, which is especially suitable for wet casting without anti-hydration treatment. The dispersion and gelation behavior of AlON slurries by isobutene maleic anhydride copolymer (Isobam104) and tetramethylammonium hydroxide (TMAH) were extensively investigated. With the addition of 0.9 wt% Isobam104 and 15 mL/L TMAH, the AlON slurries can achieve a solids loading of up to 45 vol% with the lowest viscosity (460.4 mPa·s-10 r/min) and the AlON green body is free of cracks and deformation during drying and demolding processes. Finally, the AlON green bodies with square and polygonal irregular morphologies were fabricated via a simple SCC method. High transparent AlON ceramics of a maximum transmittance up to 77.3% at 2000 nm and 72.2% at 632 nm were obtained by pressureless sintered at 2000 °C for 6 h. The SCC method has great potential in preparing ceramics with controllable shapes.

The Syntheses of Chromium Aluminum Carbide (Cr2AlC) MAXPhase and Cr2CTx MXene and Investigation of Their Antimicrobial Properties.

Chromium aluminum carbide (Cr2AlC) MAX phase and Cr2CTx (MXene-Cr) were synthesized by the pressureless sintering method and hydrothermal method, respectively. In addition to this, the free radical scavenging activities (FRSA) of MAX-Cr phase and MXene-Cr compounds were tested and compared with ascorbic acid and trolox as standard compounds. The obtained FRSA results of MAX-Cr phase and MXene-Cr were 42.82 and 59.64%, respectively, at 100mg/L concentration. MXene-Cr showed a 66.90% inhibitory effect on α-amylase at 200mg/L. The DNA nuclease activity of compounds was determined to be extremely satisfactory at 50, 100, and 200mg/L concentrations. Moreover, the prepared MAX-Cr phase and MXene-Cr were investigated for antimicrobial activity against six bacterial and two fungal strains by the broth microdilution method. Compounds provided more significant inhibition against Gram-positive bacteria than Gram-negative bacteria and fungi. MAX-Cr phase and MXene-Cr almost completely inhibited microbial cell viability at a 25mg/L concentration. Additionally, MXene-Cr showed 89.86% and 87.01% antibiofilm activity against S. aureus and P. aeruginosa, respectively, while the antibiofilm activity of the MAX-Cr phase was over 90%.

Preparation and Tribological Behaviors of Antigorite and Wollastonite Mineral Dual-Phase-Reinforced Polytetrafluoroethylene Matrix Composites

Research on polymer matrix composites with excellent tribological properties has received increasing attention in recent years. In this study, antigorite and wollastonite mineral dual-phase-reinforced polytetrafluoroethylene (PTFE) matrix composites were prepared by filling PTFE with mineral powders using ball-milling, cold-pressing, and pressureless sintering methods. The phase structure, microstructure, chemical composition, Shore hardness, and tribological behavior of the composites rubbed against steel balls under dry friction conditions were investigated. The results show that the composites have a dense structure and uniform distribution of mineral phases, with a Shore hardness of 62–68.8, an increase of 18.7–23.7% compared to pure PTFE. Compared with the addition of mono antigorite or wollastonite, the composites prepared by simultaneously filling the two minerals exhibited excellent tribological properties. The average friction coefficient and wear volume of the (10Atg + 20Wl)/PTFE composites were reduced by 44.2% and 71.4%, respectively, compared to those of pure PTFE. A dense and continuous tribofilm composed mainly of SiO2, MgSiO3, Mg2SiO4, MgO, CaO, CaMg(SiO3)2, and CaF2 was formed on the worn surfaces of both the dual-phase-reinforced PTFE matrix composites and counterpart steel balls during the friction process. The reduction in friction and wear is attributed to the reinforcement effect of the minerals on the PTFE matrix as well as the complex physical and chemical reactions at the friction interface stimulated by the synergistic effects between the two minerals. The addition of wollastonite reduced the phase transition temperature of antigorite, promoting more tribochemical reaction products with good abrasion resistance and friction-reducing properties, which contributed to the excellent tribological behavior of the composites.

Reusable mechano-bactericidal surface with echinoid-shaped hierarchical micro/nano-structure

Biofilms formed owing to the attachment of bacteria to surfaces have caused various problems in industries such as marine transportation/logistics and medicine. In response, many studies have been conducted on bactericidal surfaces, and nanostructured surfaces mimicking cicada and dragonfly wings are emerging as candidates for mechano-bactericidal surfaces. In specific circumstances involving mechano-bactericidal activity, certain nanostructured surfaces could exhibit their bactericidal effects by directly deforming the membranes of bacteria that adhere to these nanostructures. Additionally, in most cases, debris of bacterial cells may accumulate on these nanostructured surfaces. Such accumulation poses a significant challenge: it diminishes the mechano-bactericidal effectiveness of the surface, as it hinders the direct interaction between the nanostructures and any new bacteria that attach subsequently. In specific circumstances involving mechano-bactericidal activity, certain nanostructured surfaces could exhibit their bactericidal effects by directly deforming the membranes of bacteria that adhere to these nanostructures. Additionally, in most cases, debris of bacterial cells may accumulate on these nanostructured surfaces. Such accumulation poses a significant challenge: it diminishes the mechano-bactericidal effectiveness of the surface, as it hinders the direct interaction between the nanostructures and any new bacteria that attach subsequently.In other words, there is a need for strategies to remove the accumulated bacterial debris in order to sustain the mechano-bactericidal effect of the nanostructured surface. In this study, hierarchical micro/nano-structured surface (echinoid-shaped nanotextures were formed on Al micro-particle’s surfaces) was fabricated using a simple pressure-less sintering method, and effective bactericidal efficiency was shown against E. coli (97 ± 3.81%) and S. aureus (80 ± 9.34%). In addition, thermal cleaning at 500 °C effectively eliminated accumulated dead bacterial debris while maintaining the intact Al2O3 nanostructure, resulting in significant mechano-bactericidal activity (E. coli: 89 ± 6.86%, S. aureus: 75 ± 8.31%). As a result, thermal cleaning maintains the intact nanostructure and allows the continuance of the mechano-bactericidal effect. This effect was consistently maintained even after five repetitive use (E. coli: 80 ± 16.26%, S. aureus: 76 ± 12.67%).

Preparation and thermal shock resistance of solar thermal storage ceramics from high calcium and high iron steel slag

To guarantee the efficiency of solar thermal power generation, the solar thermal storage material is required to have excellent thermal shock resistance to withstand the process of long-term thermal cycles. In this study, solar thermal storage ceramics were prepared using high calcium and high iron steel slag as the main raw material, adding cordierite and using the pressureless sintering method. The effects of cordierite addition on the physical properties, phase composition, microstructure, thermal storage and thermal shock resistance of the samples were investigated by XRD, SEM and so on. The results show that the addition of cordierite promotes densification and improves thermal shock resistance. The optimal level of addition is 10 %. When the temperature is 1240 °C, the bulk density and bending strength of the B5 (10 wt% cordierite) are 3.03 g cm−3 and 92.52 MPa, respectively. The bending strength of B5 after 30 thermal shock cycles is 97.06 MPa, which is 4.91 % higher than that before 30 thermal shock cycles. The thermal storage density is 867.95 kJ kg−1. This work not only analyzes the feasibility of this material for high-temperature service but also provides a new way for high-value utilization of high calcium and high iron steel slag.

Synthesis, microstructure and thermophysical properties of (La0.2Y0.2Sm0.2Eu0.2Gd0.2)2Zr2O7 high-entropy oxide ceramic

In this study, a dense high-entropy oxide ceramic (La0.2Y0.2Sm0.2Eu0.2Gd0.2)2Zr2O7 with a relative density of 93.7 %RD was synthesized by cold isostatic pressing, coupled with the pressureless sintering method. The microstructure and physical properties were characterized systematically, revealing an intrinsic hardness of 7.9 GPa and flexural strength of 187.9 MPa. Moreover, the elastic and shear moduli decreased from 148.05 to 56.68 GPa at 25 °C to 117.44 and 44.63 GPa at 1200 °C, respectively. The thermal diffusivity in the temperature range of 25–1200 °C decreased from 0.0053 to 0.0041 cm3/s, and the thermal expansion coefficient was 11.0 × 10−6 K−1. The excellent thermal insulation performance of the high-entropy oxide ceramic (La0.2Y0.2Sm0.2Eu0.2Gd0.2)2Zr2O7 and its similar thermal expansion coefficient to those of Ni-based superalloys demonstrate that the material has broad application prospects in the field of thermal barrier coatings.

Densification and grain growth of UO2 and MnO-UO2 during pressureless sintering

Large-grain UO2 has attracted much attention due to its advantage of suppressing fission gas release by reducing the specific surface area of grain boundaries. In this study, a single grain growth additive MnO is selected to modify UO2 by conventional pressureless sintering method. The effect of MnO modification on UO2 densification and grain growth at temperatures between 1200 and 1700 °C was investigated in detail. 0.5 wt%MnO-UO2 pellets can reach nearly 95% T.D. when sintered at 1200 °C for 24 h. An average grain size greater than 300 µm can be obtained at 1700 °C for 24 h. A series of sintering experiments were designed and conducted to verify the specific mechanism of MnO on the grain growth of UO2. The classical grain growth kinetics indicates that the grain growth exponent of MnO modified UO2 in the early stage is 3, which corresponds to the lattice diffusion under pore control, while that of UO2 is 2 and conforms to the grain boundary migration control. The SEM results show that there is solute segregation of MnO at the grain boundaries, followed by nucleation of lamellar structure in the form of piles and plates on the boundaries after high temperature treatment and traces of liquid phase in some region. Diffusion sintering experiments show that the mechanism of MnO-promoted UO2 grain boundary migration is based on solid phase diffusion. The XRD results of UO2 modified with different amounts of MnO demonstrate that the growth degree of UO2 grains can be related to the variation of lattice parameters resulted from the MnO modification. This is due to the enhanced mobility of UO2 grain boundaries because of the large distortion of surrounding lattice caused by Mn modification. These results can provide new ideas for the manufacture of UO2 ceramic fuels.

Processing of V2AlC MAX phase: Optimization of sintering temperature and composition

The Vanadium MAX phase (V2AlC) was synthesized by the pressureless sintering method using elemental V, Al, and C powders as starting materials. The synthesis process involves varying the aluminum molar ratios and temperature to fully realize the optimal conditions for MAX phase synthesis. Systematic variation of the aluminum molar ratio in the range of 1.2 to 1.4 reveals that an aluminum ratio of 1.2 minimizes side reactions and compensates for aluminum loss due to the compound's volatility, optimizing Vanadium MAX phase synthesis. Furthermore, this research examines the profound impact of synthesis temperature on the composition and structure of the Vanadium MAX phases. The results indicate that the ideal temperature for achieving maximum yield, phase purity, crystallinity, and the desired microstructure is 1300 °C. Scanning electron microscopy (SEM) analysis reveals the intricate nanolaminate structure of MAX phases, characterized by fluctuations in layer thickness. Notably, we observe an average particle size of 8.27 μm, with sample 1 and sample 3 exhibiting the largest and smallest sizes at 9.51 μm and 7.28 μm, respectively. The highest conductivity, reaching 7.19E-5 S/m, and the purest samples are consistently obtained at 1300 °C with an aluminum ratio of 1.2, reaffirming the optimized conditions. In summary, this research unveils the intricate chemistry of factors influencing the synthesis of Vanadium MAX phases, shedding light on their immense potential and offering new perspectives and possibilities in MAX phase synthesis.

Preparation of extraordinary high-density indium-tin oxide target on the basis of pressure-less sintering method

Density is the most important parameter determining the performance of indium-tin oxide (ITO) targets. However, the full densification of ITO ceramics is extremely difficult. Previously reported strategies are based on the addition of components such as sintering aids or significant process adjustments. In this study, we aimed to realise the full densification of an ITO target by the fine regulation of parameters involved in the conventional pressure-less sintering process. The phase transitions, BET surface area, and particle size changes of indium-tin co-precipitated nanoprecursors sintered at different temperatures were studied. Moreover, the effects of the ITO powder state and sintering temperature on the density, resistivity, and microstructural uniformity of the ITO target were investigated. The results showed that the existence of rhombohedral In2O3 in the ITO powder and ceramic sintering temperature are vital to the full densification of the ITO target. Density was found to dominate ITO-target resistivity when the sintering temperature was <1585 °C. In this study, an extraordinary high-density (99.81 %), low-resistivity (1.707 × 10−4 Ω cm), and uniform-microstructured ITO target is prepared under optimised operation conditions.

Fabrication of beryllium oxide based fully ceramic microencapsulated nuclear fuels with dispersed TRISO particles by pressureless sintering method

In this research paper, two types of tristructural isotropic (TRISO) particles were dispersed within beryllium oxide (BeO) matrix using the pressureless sintering method to create fully ceramic microencapsulated (FCM) nuclear fuel. The findings indicated that TRISO particles with an outermost layer comprising silicon carbide (SiC) can establish interfacial bonding with BeO matrix, while those with an outermost layer comprising pyrocarbon (OPyC) and BeO matrix exhibit a noticeable gap after the sintering process. Results from transmission electron microscopy (TEM) revealed the presence of an amorphous phase transition zone between SiC and BeO. This zone, according to molecular dynamics (MD) simulation results, is an amorphous phase composed of Be, Si, and O atoms. Overall, TRISO particles with an outermost layer of SiC are more suitable for sintering with BeO matrix than those with an outermost layer of OPyC.

Preparation and characterization of all-particle SiC ceramic filters

All-particle porous SiC ceramic filters were prepared by injection moulding and pressureless sintering methods. All-particle porous SiC ceramic filters were successfully prepared by using 1 mm SiC large particles as the main raw material and alcohol solutions of Al2TiO5, MgO, CeO2 and Polyvinyl Butyral (PVB) as slurry. Highly pure Al2TiO5 was successfully prepared at 1600 °C and a holding time of 2 h. The effect of the PVB content of the paste on the morphology and properties of the samples after demoulding was investigated. The effects of sintering temperature, holding time, MgO content, and CeO2 content on the mechanical properties of all-particle porous SiC ceramic filters were discussed. It was finally determined that 69 wt% of Al2TiO5, 6 wt% of MgO, 3 wt% of CeO2, and 2 wt% of PVB was the best performance of the samples. The experimental results show that the final sintering temperature for all-particle porous SiC ceramic filters was 1400 °C and the holding time was 20 min. At this time, the flexural strength, apparent porosity, and density of the sample were 6.6788 MPa, 42.1242 %, and 1.8319 g cm−3, respectively.

Magnetic-dielectric synergistic construction of Ni-doped Ti3AlC2 achieving efficient microwave absorption

Doping can introduce diverse interfaces and optimize impedance matching, making it a significant approach for enhancing the substrate's microwave absorption performance (MAP). Herein, a novel Ni-doped Ti3AlC2 composite (xNi-Ti3AlC2; x = 0, 0.1, 0.2, 0.3) is successfully fabricated using pressureless sintering method. Partial replacement of Al atoms with doped Ni atoms leads to an improvement in permeability. Simultaneously, the substitution of Ni for Al and the formation of metal oxides (such as Al2O3, NiO, etc.) weaken the construction of conductive network, resulting in reduced conductivity and permittivity. The magnetic-dielectric synergistic effect significantly improves the impedance matching of Ti3AlC2. Furthermore, the presence of multiphase interfaces and heightened defects results in an augmentation of both interfacial polarization and dipole polarization. Consequently, the 0.2Ni-Ti3AlC2 demonstrates an outstanding MAP, with a minimum reflection loss (RLmin) of -48.73 dB at 14.33 GHz and an effective absorption bandwidth (reflection loss < -10 dB) of 4.38 GHz (11.43-15.81 GHz) at a thickness of 1.72 mm, surpassing that of Ti3AlC2. Moreover, the 0.1Ni-Ti3AlC2 achieves a RLmin of -65.07 dB, which is 4.24 times that of Ti3AlC2. This study provides a valuable reference for assisting in the design and development of an absorber that capitalizes on magnetic-dielectric synergistic effect.

Phase and structural evolution of dysprosia stabilized zirconia ceramics under CMAS corrosion environment

In this study, 10 wt % dysprosia stabilized zirconia (10DySZ) ceramics were prepared by pressureless sintering method. The CMAS corrosion behaviors of DySZ ceramics were investigated and the corrosion mechanism was also discussed in detail. Results show that the CMAS corrosive agent can induce phase transformation of DySZ ceramic due to the stronger ability to capture Dy stabilizers than Zr ions. During the corrosion process, molten CMAS would preferentially corrode the grain boundaries and then infiltrated into the interior of DySZ ceramic, resulting in the formation of loose structure on the ceramic surface. Sandy-shaped DySZ particles were also formed in the residual CMAS layers based on dissolution and precipitation mechanism. The corrosion temperature plays a crucial role in accelerating the phase transformation and thermal-mechanical damage of DySZ ceramic. Mismatch of thermal expansion coefficient between CMAS and DySZ ceramics as well as composition and structural difference between dense layer and porous layer are all responsible to the formation of destructive cracks.

Pressureless-sintered boron nitride nanosheets/glass composite ceramics for excellent mechanical, dielectric and thermo-conductive performances

Because they have a high application potential in the thermal management of insulation environments, high-quality hexagonal boron nitride (h-BN)-based multiphase ceramics have been highly desired. However, so far, their synthesis is still full of challenges. Here, a kind of boron nitride nanosheets (BNNSs)/glass (GS) composite ceramics was prepared by a pressureless sintering method at a lower temperature of 900 °C. Due to a tightly bonded interaction between BNNSs and GS, the formed BNNSs/GS ceramics exhibit excellent multifunction performance. They have an outstanding compressive strength in the range of 19 ∼ 64 MPa and Vickers hardness ranging from 50 to 179 HV. For the BNNSs/GS ceramics with BNNS’s filling fraction of 90 wt%, their maximum side-surface TC values are 12.01 ± 0.18 W m−1 K−1 at 25 °C and 13.64 ± 0.37 W m−1 K−1 at 300 °C, respectively. In the ultra-high frequency range of 26.5 ∼ 40 GHz, the dielectric constant values of the BNNSs/GS ceramics are primarily between 2 and 3, and the corresponding loss tangent values are < 0.3. In addition, based on the remarkable integrity of their structure, these BNNSs/GS ceramics exhibit outstanding thermal-shock stability and prominent thermal management capacity during lots of heating/cooling-testing cycles. Therefore, we believe this kind of BNNSs/GS ceramic system will have great application potential in the new-generation thermal management and/or insulation packaging fields.

PRODUCTION OF TRANSLUCENT ALUMINA CERAMICS BY TAPE CASTING

Alumina powders are utilized in many industries like electronics, metallurgy optoelectronics, and fine ceramic composites. In this study, non-aqueous-based tape casting of alumina was carried out in a non-continuous single-blade tape casting machine. A slurry of alumina powder in a solvent was cast on a stationary surface with additives like dispersants, binders, and plasticizers. After the green tapes were dried, they were sintered to obtain the final desired shape. The hydraulic pressing method was used to increase the density of the alumina tapes. Layered alumina ceramics were produced at 5 different temperatures by pressureless sintering method (1450°C, 1500°C, 1550°C, 1600°C and 1650°C) for 5 h to observe the effect of sintering temperature. Results revealed the sintering conditions for obtaining translucent alumina, with the utilized slurry composition. Translucent alumina ceramics have gained importance as parts of semiconductor devices, substrates for electric parts, as heat/corrosion materials in reaction tubes and crucibles, and are used in medical equipment.

Study on wettability behavior and wear resistance mechanism of ZTA-ceramic-reinforced HCCI composites

ABSTRACT Zirconia-toughened alumina (ZTA)-reinforced high-chromium cast iron (HCCI) composite materials were prepared using pressureless sintering method, and the effects of the type (titanium (Ti), nickel (Ni)) and content (10%, 12%) of active additives on the wettability and wear resistance were systematically studied. Result showed that the additive can enhance the wettability capacity between ZTA/HCCI composites interface, especially Ti, which reacted the chemical reaction and formed a transition layer in metallurgical combination. When the content of the Ti additive was 10%, the Brinell hardness (HB) of ZTA/HCCI composite was 573.1 N/mm2 at room temperature, and the wear-resistant properties were more than 3.8 times of pure HCCI. After thermal treatment, the HB and wear resistance of 10% Ti-ZTA/HCCI composites increased significantly which could reach 629.8 N/mm2 and were more than 4.3 times of the pure HCCI, respectively.

Preparation and microstructure evolution of W-Fe-B ternary system

W-Fe-B ternary system with different process parameters were fabricated the pressureless sintering method. Effects of sintering of Fe, FeB and W raw powders on the synthesis behavior of W-Fe-B alloy were systematically investigated. The results showed that the density of W-Fe-B alloy is 10.5 g/cm3. The hardness, compressive strength and bending strength first increased and then decreased with sintered temperature increasing from 1270 °C to 1330 °C and holding time maintaining 1 h to 2.5 h. Synthesized W-Fe-B alloys have superior comprehensive properties with hardness of 531.4 ± 0.4 HV and bending strength of 955 ± 2 MPa in holding 2 h under 1300 °C. According to the results of tests, high performance W-Fe-B alloy would make greater contributions in future cutter and mould industries.

Thermal stress durability and optical characteristics of a promising solar air receiver based black alumina ceramics

In solar thermal technology, solar receiver materials with high solar absorptivity and photocatalytic efficiency have recently become a mandatory requirement for promoting and maximizing the released thermal and electrical energy. This paper presents a detailed study of the optical performance and thermal stress durability of the promising solar receiver material, black Al2O3/CuO ceramics. Different Al2O3/CuO ceramics with different CuO content (10–40 wt%) were obtained by the pressureless sintering method. Optical properties such as solar absorbance and reflectance, band gap energy and photoluminescence are inclusively investigated. The thermal stress resistance of the obtained ceramic receivers is simulated using the finite element modeling (FEM) method at different temperatures. Results indicated that adding and increasing the content of CuO to Al2O3 has a significant role in transforming alumina from a non-solar light-absorbed material to a solar absorber material with high absorptivity in the Ultraviolet–Visible-Near Infrared (UV-VIS-NIR) spectrum. Composite with 40 wt% CuO has recorded the maximum absorbance of 75% in the visible light region. Moreover, Al2O3/CuO ceramics gave multiple graded band-gaps in the range of (1.6–5 eV). Composites with high wt% of CuO have the most increased photocatalytic activity and light emissivity efficiency. Thermal stress analysis of the different ceramics showed outstanding stress durability with uniform heat distribution. Hence, black Al2O3/CuO ceramics can be considered ideal solar absorber materials with high sustainability and durability at high temperatures.

YAlO3 reinforced AlN composite ceramics with significantly improved mechanical properties and thermal shock resistance

AlN is regarded as a promising ceramic material for high performance structural and high temperature applications due to its superior properties such as high thermal conductivity, excellent stability and wear resistance. However, challenges remain in fabricating AlN ceramics with high strength and high thermal shock resistance. In this work, AlN/YAlO3 composites with different YAlO3 contents (3–10 wt%) were prepared by a simple pressureless sintering method, and the impact of YAlO3 content on mechanical properties and thermal shock resistance of AlN/YAlO3 composites was investigated. Results show that the grain growth of AlN is inhibited and the densification is improved with the addition of 3 wt% and 5 wt% YAlO3. Hence, the flexural strength and fracture toughness of AlN/YAlO3 composites are improved due to the grain refinement and compactness enhancement, and the highest value, 369 MPa and 3.84 MPa m1/2, are reached by the AlN-5 wt% YAlO3 composite. Moreover, the thermal shock resistance was assessed through theoretical forecast and cyclic thermal shock tests over a temperature range between 1000 °C and 1600 °C. Comparing with pure AlN, the thermal stress damage resistance parameters (RIV) of AlN/YAlO3 composites were increased, while their residual strengths and retention ratios after 10–50 cycles of thermal shock tests maintained a higher level as well. Microstructure analysis revealed that the thermal shock resistance of AlN/YAlO3 composites was evidently improved attributing to various strengthening mechanisms such as crack deflection, crack branching and microcrack toughening.