High Temperature Thermal Stability Research Articles

Synergistic grain boundary engineering for achieving strength-ductility balance in ultrafine-grained high-Cr-bearing multicomponent alloys

Precipitation strengthening is a crucial strategy for ensuring the overall performance of conventional and multicomponent alloys to meet industrial demands. However, the mechanical properties of high-Cr-bearing alloys are often compromised by brittle Cr-rich precipitates at grain boundaries (GBs), leading to severe embrittlement. In this work, a multi-step thermomechanical process is employed to regulate discontinuous dynamic recrystallization (DDRX) and static recrystallization, achieving an ultrafine-grained microstructure. This optimized approach simultaneously impedes the continuous precipitation of the ordered L12 nanocrystals within the matrix and actively encourages the synergistic discontinuous precipitations of submicron L12 and Cr-rich σ particles at GBs, thereby enhancing (yield) strength and high-temperature thermal stability. The ultrafine grains facilitate uniform plastic deformation, characterized by pronounced parallel dislocation slip and stacking faults (SFs) within face-centered cubic (fcc) grains, while second-direction slips, SFs, and Lomer-Cottrell (L-C) lock networks near GB precipitates greatly alleviate stress concentration. Critically, the submicron L12 particles enveloping σ precipitates at GBs also display plastic deformation via mechanical twinning and dislocations, effectively impeding rapid crack propagation along GBs. This research not only provides new insights into the ductility-strength balance in advanced alloys but also proposes a compelling route for optimizing biphasic precipitation, expanding the applicability of high-Cr multicomponent alloys.

Interfacial modulation of SiC/TiC hybrid nanofibers for fabricating flexible ceramic electromagnetic wave absorbers

Titanium Carbide (TiC), characterized by its hardness, conductivity and thermal stability, can serve as a suitable additive phase for SiC nanofibers. TiC phase can improve the flexibility and electromagnetic wave absorption property of SiC nanofibers without sacrificing its high-temperature thermal stability. Herein, flexible SiC/TiC hybrid nanofibers with different Ti contents were fabricated by electrospinning and precursor infiltration pyrolysis. The introduction of Ti can not only generate conductive TiC phase, but also act as a catalyst to regulate the growth of SiC grains, so as to adjust the flexibility and electromagnetic properties of the hybrid nanofibers. At the optimal Ti precursor content of 4 wt%, the SiC/TiC-4 hybrid nanofibers exhibit a broad effective absorption bandwidth of 4.5 GHz with the thickness of 1.6 mm. The flexible SiC/TiC hybrid nanofibers This work can provide a reference for the design of flexible ceramic nanofiber absorbers and is expected to enable practical application in high temperature conditions.

Low-κ, low CTE, high-temperature epoxy resin with high storage modulus based on spirobisindane for high-frequency electronic circuit field

High-temperature thermosetting resin with low dielectric constant (κ), low thermal expansion coefficient (CTE), and high modulus are drawing more and more attention from scientists and engineers in the field of the high-frequency circuit, 5G and 6G communication networks to improve the signal transmission speed. Epoxy resin, as one of the important thermosetting resin members, possesses excellent properties such as heat resistance, cohesiveness, and reactivity. However, Epoxy resin was usually mixed with different inorganic fillers to meet the above requirements, especially to decrease the κ and CTE. In this work, a new class of spirobisindane epoxy resin monomer (TSDEP) was synthesized by a classic two-step method based on 3,3,3′,3′-tetramethyl-1,1′-spirobisindane-6,6′-diol (TSD). Due to the highly distorted rigid structure of TSD, the movement of the TSDEP molecular segment is subject to more restrictions after being cured, and the free volume will increase. After cured by 4,4′-diamino diphenyl sulfone (DDS), the TSDEP/DDS resin exhibited many desirable physical properties, e.g., low dielectric constant (∼3.45, 1 MHz), low dielectric loss (∼0.025, 1 MHz), low coefficient of thermal expansion (CTE, 72 ppm/ °C, 35–150 °C), high glass transition temperature (Tg > 241 °C) and high thermal stability (Td5%∼400 °C). Furthermore, TSDEP/DDS exhibited excellent mechanical rigidity with a storage modulus of ∼ 3.1 GPa. Compared with TSDEP/DDS, 4-methylhexahydrophthalic anhydride (MHHPA) cured TSDEP system showed lower κ (∼3.09) and dielectric loss (0.015) due to weaker polar ester groups instead of more polar hydroxy groups.

Nanostructured Yb2SiO5/mullite-SiC/Si environmental barrier coating with long-term stability at 1250 °C

In this work, nanostructured Yb2SiO5/mullite-SiC/Si environmental barrier coatings (EBCs) were prepared to investigate the effect of heat treatment on the microstructure and phase transition of nanostructured Yb2SiO5/mullite-SiC/Si coatings. The Yb2SiO5 content and microstructure evolution in the coatings were thoroughly analyzed before and after heat treatment. The results demonstrate a slight decrease in the porosities of nanostructured Yb2SiO5 and mullite-SiC coatings, accompanied by a gradual growth in grain sizes with increasing heat treatment time, indicating the nanostructured EBCs show good resistance to sintering. Moreover, the thickness of thermal growth oxidation layer is only 200 nm at 1250 °C for 500 h of heat treatment. In particular, the presence of the Yb2O3 phase has been observed to exert a favorable influence on the thermal stability of nanostructured EBCs. This work provides an innovative strategy for designing advanced EBCs with excellent high-temperature thermal stability.

SiC@NiO Core-Shell Nanowire Networks-Based Optoelectronic Synapses for Neuromorphic Computing and Visual Systems at High Temperature.

1D nanowire networks, sharing similarities of structure, information transfer, and computation with biological neural networks, have emerged as a promising platform for neuromorphic systems. Based on brain-like structures of 1D nanowire networks, neuromorphic synaptic devices can overcome the von Neumann bottleneck, achieving intelligent high-efficient sensing and computing function with high information processing rates and low power consumption. Here, high-temperature neuromorphic synaptic devices based on SiC@NiO core-shell nanowire networks optoelectronic memristors (NNOMs) are developed. Experimental results demonstrate that NNOMs attain synaptic short/long-term plasticity and modulation plasticity under both electrical and optical stimulation, and exhibit advanced functions such as short/long-term memory and "learning-forgetting-relearning" under optical stimulation at both room temperature and 200°C. Based on the advanced functions under light stimulus, the constructed 5×3 optoelectronic synaptic array devices exhibit a stable visual memory function up to 200°C, which can be utilized to develop artificial visual systems. Additionally, when exposed to multiple electronic or optical stimuli, the NNOMs effectively replicate the principles of Pavlovian classical conditioning, achieving visual heterologous synaptic functionality and refining neural networks. Overall, with abundant synaptic characteristics and high-temperature thermal stability, these neuromorphic synaptic devices offer a promising route for advancing neuromorphic computing and visual systems.

A Comparative Study about Production of Va nadium Carbide via Self Propagating High Temperature Synthesis and Reduction

Vanadium carbide is important for industrial applications because of its high hardness, high temperature resistance, high chemical, and thermal stability. It is generally obtained from the reaction between V and C powders at a high temperature ranging from 1100 to 1500°C. Investigations on these high strength, high abrasion resistant, hard materials have been intensified in recent years and consequently, significant improvements have been achieved. In this study, VC alloys are produced with low cost processes, by reducing the oxides of their components by SHS methods and ball mill-assisted carbothermal reduction. In the experimental stage, V2O5 was used as oxidized Vanadium source, Cblack as carbon source, magnesium and Cblack as reductant. In the study, VC powders were synthesized by two different methods and optimum production conditions were determined. Furthermore, the effect of different stoichiometric charge components and the effect of experiment durations were realized by X-ray diffraction, HSC Chemistry, and SEM analyses for different reductants.

Creep behavior and precipitation evolution of Mg-13Gd-2Y-0.5Zr alloy

With exceptional aging hardening effect and a heat resistance temperature up to 250 °C, MgGd alloys have great application prospects in heat-resistant components in new energy vehicle power systems, aviation and aircraft systems, atc. In this study, the creep properties of the Mg-13Gd-2Y-0.5Zr (GW132) alloy at 200–270 °C/ 110–150 MPa are investigated, and the constitutive equation of the steady creep rate is constructed, focusing on the evolution of the precipitated phase in the α-Mg matrix at 250 °C/150 MPa. The alloy exhibits good creep resistance at 200–250 °C/ 110–150 MPa and 270 °C/ 110 MPa. During creep at 250 °C/ 150 MPa for 200 h, the evolution sequence of α-Mg matrix precipitates is mainly β’ phase → β’ + β1 phase → β’ + β1 + β + 18R-LPSO phase, β’, β1, β and 18R-LPSO phases can coexist in the same creep state. The β’ phase is maintained at a large volume fraction and forms a string with the β1 phase. The string-like precipitates are connected to each other to form a continuous dense grid module. Moreover, the β’ phase and the 18R-LPSO phase have excellent high-temperature thermal stability and are coherent with the α-Mg matrix, enabling the alloy to have excellent creep resistance in a certain temperature range. The creep mechanism of the GW132 alloy at 250 °C/ 150 MPa is dominated by the diffusion of Gd and Y atoms and the dislocation slip.

Nano-alumina islands enabling superior capacitive lithium-ion storage of pitaya configuration

Currently, high-temperature thermal failure hinders the development of lithium-ion batteries (LIBs). Interfacial side reaction of electrolyte and electrode is the main cause of thermal failure at high temperature. Explicitly, suppressing interfacial side reactions at high temperatures can help the research of capacitive energy storage electrodes. While, thermo-electrochemical inert alumina can be facilitated to solve this problem. In this paper, pitaya configuration of nano-alumina islands uniformly dispersed in carbon matrix can be achieved from NOTT-300(Al). Nano-alumina contributes to the structural stability of porous carbon during carbonization and lithium deintercalation. And nano-alumina islands are effective in suppressing interfacial side reactions at high temperatures. Thus, NC-3 exhibits competitive specific capacity (717.1 mAh/g) and cycling stability (99.15% after 500 cycles). NC-3's capacity was confirmed to be mainly attributed to capacitive energy storage mechanism. This study provides a new research paradigm for nano-alumina to improve the high-temperature thermal stability management of LIBs.

Eco-friendly surface coating of wool/polyester blend fabric using a combination of montmorillonite and polyquaternium 10: Enhanced flame-retardant performance using layer-by-layer assembly

Wool and polyester blends are sensitive to heat and pose fire hazards. In this study, the flame retardancy of wool/polyester blended fabric was improved by coating montmorillonite (MMT) and polyquaternium-10 (PQ-10) using the layer-by-layer assembly (LBL) method. This was done to confirm the feasibility of combining eco-friendly materials such as MMT and PQ-10 coatings and to secure the flame retardancy of the wool/polyester blend. The phosphate-buffered solution enhanced the intermolecular forces during pretreatment. Scanning electron microscopy and Fourier-transform infrared spectroscopy analyses confirmed the successful deposition of the MMT/PQ-10 combination on the fabric, and the deposition on the fabric surface increased as the number of coating layers increased. The thermogravimetric analysis results showed that the MMT/PQ-10 combination effectively reduced the maximum decomposition temperature, contributing to improved high-temperature thermal stability. Additionally, compared with the untreated fabrics, the coated fabrics exhibited a 38.2% increase in residual substances, and flame-retardant properties enhanced up to 27.3%. As a result of the vertical flame test, the MMT/PQ-10 combination improves the cohesiveness of the fabrics and prevents melt dripping, contributing to the improvement of flame retardancy.

Synthesis and characterization of fluorinated polyurethaneimide electro-optic waveguide material with novel structure

Abstract Structurally novel fluorinated polyurethaneimide (PUI) electro-optic polymer based on chromophore molecule b, diisocyanate MDI and anhydride BPAFDA was synthesized by stepwise polymerization of oligomer PUI with fluorinated aromatic diamines BATB and BATPP. Electro-optic (EO) PUI chain structure had the structure of polyimide and polyurethane chain segments, integrating the advantages of polyimide and polyurethane. The PUI possessed good film-forming property, a high glass transition temperature (T g = 193 °C) and good thermal stability (5 % weight loss temperature T d up to 320 °C). Y-Structured inverted ridge polymer optical waveguides were designed and fabricated using the PUI as the waveguide core material. The PUI had good optical performance with an EO coefficient (γ33) of 79 pm/V and 1.1 dB/cm optical propagation loss at a wavelength of 1550 nm. The results showed that the synthesized PUI met the performance requirements for the preparation of polymer optical waveguide devices and was suitable as a polymer electro-optic waveguide material.

High-Temperature Thermal Stability of Hot Isostatic Pressed Co25.1Cr18.8Fe23.3Ni22.6Ta8.5Al1.7 (at%) Eutectic High-Entropy Alloy

An eutectic high-entropy alloy (EHEA) consisting mainly of a face-centered cubic (FCC) phase and a C14 Laves phase with the compositions of Co25.1Cr18.8Fe23.3Ni22.6Ta8.5Al1.7 (at%) was successfully prepared by hot isostatic pressing. The present EHEA exhibits a skeleton-type Laves phase structure, deviating from typical EHEA structures. After a series of annealing treatments at 1000 °C for different durations (ranging from 0 to 150 h), the Co3Ta phase precipitated after annealing. The mechanical properties measured at 850 °C showed a tensile strength of 441 MPa and an elongation of 3.3%. The results of the high-temperature tests showed that the mechanical properties of this alloy did not change significantly before and after annealing, and its microstructure showed a high degree of stability, which suggests that the material has some potential for use in high-temperature environments.

Evaluation of the Thermal Stability and Micro-Modification Mechanism of SBR/PP-Modified Asphalt.

To evaluate the thermal stability of composite polymer-modified asphalt, thermoplastic elastomer styrene-butadiene rubber (SBR)/polypropylene (PP) pellets were prepared using a hot-melt blending technique, with butyl rubber powder and waste polypropylene pellets as raw materials. The effects of different evaluation indexes on the thermal stability of SBR/PP-modified asphalt were investigated using a frequency scan test and a multi-stress creep recovery (MSCR) test, and the compatibility of SBR/PP particles with asphalt was studied using the Cole-Cole diagram and microstructure images. The tests show that, firstly, the performance grade (PG) classification of asphalt can be improved by adding an SBR/PP thermoplastic elastomer to enhance the adaptability of asphalt in high- and low-temperature environments, and the evaluation separation index can reflect the high-temperature storage stability of composite-modified asphalt more reasonably. Additionally, the larger the rubber-to-plastic ratio the worse the high-temperature thermal stability of composite-modified asphalt. Moreover, the addition of additives to the composite particles can promote the SBR/PP particles in the asphalt to be more uniformly dispersed, forming a more desirable microstructure and improving the thermal stability of composite-modified asphalt. Ultimately, the semicircular curve of the Cole-Cole diagram can reflect the compatibility characteristics of the two-phase structure of SBR/PP-modified asphalt, which can be used as an auxiliary index to evaluate the compatibility of polymer-modified asphalt.

Compatibility evaluation between waterborne epoxy resin and SBR latex modified asphalt emulsion

Good compatibility between waterborne epoxy resin (WER) modifier and styrene-butadiene rubber (SBR) latex modified asphalt emulsion (SBRE) is an essential premise for good pavement performance of WER and SBR latex compositely modified asphalt emulsion (WSAE). This study aims to explore the compatibility between WER modifier and SBRE. To achieve the goal, several WER modifiers produced by two methods were first selected to modify SBRE, thus the WSAEs were prepared. Next, storage stability and workability of the WSAEs themselves, and high-temperature performance, rheological behavior and temperature sensitivity of their evaporated residues were compared and evaluated via performing a series of experiments, respectively, thus the WER modifier possessing an optimal modification effect was recommended. Results show that the storage stability of WSAEs is sensitive to the amount of WERs. The incorporation of 1% WERs by the mass of SBRE improves the storage stability of SBRE, while WERs that exceed 1% weaken its storage stability. When the WERs reach 3% and 4%, the 5 d storage stability of prepared WSAEs will be beyond the limitation of specification. Incorporating WERs into SBRE negatively affects the workability of SBRE, and the workability of WSAEs is adversely influenced by the WERs content and the storage time. To ensure the construction, the WSAEs with 3% and 4% WERs should not be stored for more than 36 h and 48 h, respectively. The WERs effectively improve the high-temperature performance of SBRE residue, especially the 3% WERs. Besides, the WERs notably enhance the rheological property and thermal stability of SBRE residue. In contrast, the WER modifier produced by chemically modified method has a smaller adverse impact on the storage stability and workability of WSAE, and a larger enhancement on the high-temperature performance, rheological property and thermal stability of SBRE residue, which is thus recommended to modify SBRE.

Epoxy lignin-modified tetraethylenepentamethylene-CO2 halogen-free blown rigid polyurethane foam

A new halogen-free blowing agent for rigid polyurethane foam, E-Lig-TEPA-CO2, was synthesized by absorbing CO2 onto tetraethylenepentamine modified with epoxy lignin. The blowing agent was modified with lignin, which introduced hydrophobic groups such as benzene rings, carbon chains, and aromatic ethers. This modification enhanced its oil affinity and compatibility in the polyol mixture. Surface tension testing showed that the surface tension of the lignin-modified blowing agent decreased from 36 to 24 mN/m. Observations through Olympus microscopy revealed that the lignin-modified blowing agent was better dispersed in the polyol mixture, with fewer air bubbles and improved compatibility. Additionally, the main raw material used for this blowing agent was low molecular weight tetraethylenepentamine, resulting in a liquid-state blowing agent. This liquid-state blowing agent inherently possessed advantages in terms of dispersibility and compatibility compared to solid-state blowing agents. Finally, self-made lignin phosphate (P-Lig), expandable graphite (EG), and dimethyl methyl phosphonate (DMMP) were added as halogen-free flame retardants. Lignin-bio-based polyol was used as partial polyol. A new type of bio-based and halogen-free blown flame-retardant rigid polyurethane foam was prepared. The resulting foam demonstrated small and evenly distributed cell structures, as well as good compression strength (224 kPa) and thermal conductivity (0.029 W/(m·k)). The limiting oxygen index of foam increased to 30.6%, reached the V-0 level during the vertical burning process, the peak heat release rate decreased to 196 Kw/m2, and high-temperature thermal stability in thermogravimetric was enhanced.

Enhanced thermal stability of pressureless liquid-phase sintered SiC ceramics via (Hf, Zr, Ta, Nb, Ti)B2 addition

High-temperature thermal stability plays a crucial role in the structural application of pressureless liquid-phase sintered SiC (PLS-SiC) ceramics. In this paper, a PLS-SiC ceramic processed with CeO2–Al2O3 as sintering additives with excellent high-temperature thermal stability was achieved by incorporating (Hf, Zr, Ta, Nb, Ti)B2 (HEB) particles. Results showed that PLS-SiC ceramics with HEB-free underwent a structural change from dense to porous microstructure after annealing at 1800 °C/1 h. Conversely, PLS-SiC ceramics with the addition of 10 vol% HEB exhibited excellent thermal stability, as evidenced by the retention of their dense microstructure after exposure to annealing at 1800 °C/1 h. The possible primary reasons for this significantly different response to the thermal stability could be probably attributed to fact that HEB reacted with CeAlO3 and SiC to form solid-phase products, subsequently inhibiting the formation of gas-phase products after decomposition of CeAlO3 alone in a high-temperature vacuum environment. In addition, the formation of a compact protective outer layer containing Hf–Ta containing diboride in PLS-SiC ceramics during the annealing process could effectively hinder the volatilization of volatile substances at a high temperature.

Synthesis and cryogenic performance of closed-loop recycled Al2O3/epoxy resins composites

The non-degradability of epoxy present environmental and economic challenges. This study synthesized a degradable epoxy resin with ester bonds using a novel method. The synthesized resin was mixed with KH560-modified micro-sized spherical α-Al2O3 particles at different concentrations to produce the A-TPHE. The cured A-TPHE exhibited excellent mechanical properties, including high tensile and shear strength (∼100 MPa), as well as outstanding impact resistance. Furthermore, DMA, DSC, and TGA analyses revealed that the composites had a high glass transition temperature (>100 °C) and good thermal stability. Notably, the A-TPHE80 % filler achieved a favorable thermal conductivity of 1.2 W/mK at 77 K. A-TPHE also demonstrated good insulation properties. The degradation of the resins was assessed at 30 wt% NaOH, and the recovered filtrate facilitated closed-loop recycling of the composite material with a consistent recovery rate exceeding 70 %. In conclusion, this study establishes a foundation for the application of degradable thermosetting materials in cryogenic environments.

Facile preparation of high-performance plywood adhesive from gelatinized corn starch crosslinked with ammonium dihydrogen phosphate

A flame retardant high-performance gelatinized starch (GS)-ammonium dihydrogen phosphate (ADP) wood adhesive, named GS-ADP adhesive was prepared by condensation of GS and ADP under acidic condition. The preparation process of GS-ADP adhesive is very simple by mixing and stirring GS and ADP evenly at room temperature. The results revealed that the GS-ADP adhesive has good storage stability and water resistance, and its wet shear strength is much higher than that of phenolic resin (PF) adhesive. Markedly, the cone calorimeter test results show that G-ADP adhesive has good flame retardancy, and the plywood based on GS-ADP adhesive has good flame retardancy. Meanwhile, it can be seen from dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) that GS-ADP has excellent modulus of elasticity (MOE), high glass transition temperature (Tg) and good thermal stability. The findings suggest that GS-ADP could be a viable substitute for PF resin in structural wood fabrication.

Precursor-derived SiHfBCN ceramics with ultrahigh temperature stability: Facile preparation, phase evolution behavior, and mechanism of ultrahigh temperature thermal stability

SiHfBCN ceramics are the most promising candidates as ultrahigh temperature ceramics for aerospace applications. In this work, PHSNB precursors were synthesized by hydrosilylation reaction of polyborosilazane (PSNB) and polyhafnocenecarbosilane (PHCS), and then the SiHfBCN ceramics can be obtained from the PHSNB precursors through the precursor-derived ceramics (PDC) strategy. The structure, composition, pyrolysis process, and phase evolution behavior at high temperatures of the SiHfBCN ceramics were systematically investigated. The results show that the optimum SiHfBCN ceramic prepared in this study can remain stable until 1780 °C, and the weight loss at 1800 °C is only 0.8 wt%, demonstrating the excellent high temperature thermal stability of the SiHfBCN ceramics. The outstanding high temperature thermal stability of the SiHfBCN ceramics can be attributed to two reasons. Firstly, the formation of HfCxN1-x solid solution at high temperatures can greatly inhibit the formation of SiNx, so the carbothermal reduction reaction and thermal decomposition reaction of SiNx can be greatly inhibited. Secondly, the generated crystal phases at high temperatures are surrounded by the chaotic layered structures of B–C–N phase, which greatly restricts the decomposition process of the SiHfBCN ceramics. This work presents a convenient strategy in preparing multiphase ceramics (not only SiHfBCN) that can be applicable in various harsh environmental conditions.

Enhanced Thermal and Dielectric Properties of Polyarylene Ether Nitrile Nanocomposites Incorporated with BN/TiO2-Based Hybrids for Flexible Dielectrics.

Outstanding high-temperature resistance, thermal stability, and dielectric properties are fundamental for dielectric materials used in harsh environments. Herein, TiO2 nanoparticles are decorated on the surface of BN nanosheets by internal crosslinking between polydopamine (PDA) and polyethyleneimine (PEI), forming three-dimensional novel nanohybrids with a rough surface. Then, an ether nitrile (PEN) matrix is introduced into the polyarylene to form polymer-based nanocomposite dielectric films. Meanwhile, the structure and micromorphology of the newly prepared nanohybrids, as well as the dielectric and thermal properties of PEN nanocomposites, are investigated in detail. The results indicate that TiO2 nanoparticles tightly attach to the surface of BN, creating a new nanohybrid that significantly enhances the comprehensive performance of PEN nanocomposites. Specifically, compared to pure PEN, the nanocomposite film with a nanofiller content of 40 wt% exhibited an 8 °C improvement in the glass transition temperature (Tg) and a 162% enhancement in the dielectric constant at 1 kHz. Moreover, the dielectric constant-temperature coefficient of the nanocomposite films remained below 5.1 × 10-4 °C-1 within the temperature range of 25-160 °C, demonstrating excellent thermal resistance. This work offers a method for preparing highly thermal-resistant dielectric nanocomposites suitable for application in elevated temperature environments.

Modification of high temperature radiation absorption properties of solid particles with surface coating

The coatings with different thermodynamic and optical properties can adjust and improve the overall performance of solid particles in solid particle solar receivers (SPSRs). In this work, the manganese iron black (PBK26) coating is prepared by water bath method and comprehensive performance of the coating is found to be the best when Fe/Mn molar ratio in PBK26 is 4:1. The high temperature radiation absorption performances of different solid particles coated by PBK26 are investigated. The results show that the spectral absorptivity of particles can be greatly improved by coating. The average spectral absorptivity of quartz sand, bauxite and mullite increases by 25.9%, 20.8% and 16.2%, respectively. However, the coated quartz sand appears coating shedding phenomenon at high temperatures, and the coating on bauxite is not complete. Only the coated mullite shows excellent coating effect and thermal stability. After long-period high temperature thermal stability experiments at 900 °C and cyclic thermal stability experiments of 30 cycles, the maximum mass loss of coated mullite is less than 0.4% and the spectral absorptivity is almost unchanged. In the wear resistance experiments the surface debris of the coated mullite increases. And there is a mass loss of 8.244% with a coating thickness loss of 27% and a spectral absorptivity decrease of 3.88% after 10 h of wear at 900 rpm. The results imply good high temperature thermal stability and acceptable wear resistance of PBK26 coated mullite, which provide an option for high temperature radiation improvement of solid particles.