Refractories

Comparative study on the interaction Between Al₂O₃/MgO refractory and Ni-based superalloys

Guo Jia, Chen Guangyao, Deng Shaowen, Liao Houjin, Wang Enhui, Hou Xinmei, Li Chonghe

2026, (3): 185-191. doi：10.3969/j.issn.1001-1935.2026.03.001

Al₂O₃ and MgO are the common refractory for melting Ni-based superalloys.In addition,their interaction with the alloy melts could directly affect the purity of the alloys.In this study,Superalloy GNPM01 ingots were VIM using Al₂O₃ and MgO crucibles,respectively.The phase composition,microstructure,and variations in oxygen content in the alloy before and after contact between the two crucibles and the alloy melt were comparatively investigated using X-ray diffraction (XRD),scanning electron microscopy (SEM),and oxygen/nitrogen analyzers.Furthermore,the interfacial reactions between the superalloy and Al₂O₃/MgO crucibles were systematically analyzed.The results indicates that the spalling and the dissolution of the Al₂O₃ refractory was the main causes for the oxygen and inclusion contaminations in the alloy.Due to strong affinity of Al and Cr in the alloy melt for oxygen,Al₂O₃ and Cr₂O₃ slags were easily formed on the surface of the alloy melt.In contrast,during the interaction between MgO refractory and the alloy melt,the oxygen generated from the dissolution of MgO tended to react with Al in the alloy to form Al₂O₃,which then further reacted with the matrix to form MgAl₂O₄ inclusions.This reduces the contamination from Al₂O₃-type inclusion and oxygen in the alloy,but the formation of MgAl₂O₄ could further enter the alloy melt,resulting in inclusion contamination.

Effect of CaO-Al₂O₃-B₂O₃-SiO₂ glass on crystallization behavior of fused silica

Tian Yu, Liang Feng, Lv Gongye, Gu Haohui, He Gangjun, Zhang Haijun

2026, (3): 192-197. doi：10.3969/j.issn.1001-1935.2026.03.002

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In order to effectively inhibit the phase transformation and crystallization of fused silica powder at high temperature,CaO-Al₂O₃-B₂O₃-SiO₂(CABS) glass-coated fused silica particles were prepared by sol-gel method using fused silica powder (particle size ≤ 74 μm) ,aluminum nitrate nonahydrate,calcium nitrate tetrahydrate,silica sol (solid mass fraction of 30%) and ytterbium nitrate pentahydrate as raw material.The effects of glass phase addition (mass fraction 0~9%),calcination temperature (1 100 ~ 1 300 ℃),holding time (0.5~3 h) and Yb₂O₃ addition (the molar ratio of B₂O₃ to Yb₂O₃ was 9:1,7:3 and 5:5,respectively) on the crystallization behavior of fused silica were studied.The results show that with the increase of calcination temperature,the crystallization ratio of the sample gradually increases,and the introduction of CABS glass phase can significantly inhibit the crystallization of fused silica powder at high temperature.With the increase of glass phase addition,the crystallization ratio of the sample decreases first and then increases.When the addition amount of the glass phase is 7% (w),the crystallization ratio of the sample after heat treatment at 1 300 ℃ for 2 h is only 10.01% (w),which is 86.3% lower than that of the sample without glass phase.With the increase of Yb₂O₃ addition,the crystallization ratio of the sample increases first and then decreases.When the molar ratio of B₂O₃ to Yb₂O₃ is 9:1,the crystallization ratio of the sample calcined at 1 300 ℃ for 2 h is 10.66% (w),which is 85.4% lower than that of the sample without glass phase.

Structure optimization and mechanical properties of potassium magnesium phosphate cement for high temperature

Wang Xing, Zhou Zishan, Yang Bolin, Zou Yuxin, Jing Xianwan, Chen Yuhan, Wang Xinyu, Liu Zhenglong, Deng Chengji, Yu Chao, Ding Jun

2026, (3): 198-204. doi：10.3969/j.issn.1001-1935.2026.03.003

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To optimize the service performance of magnesium potassium phosphate cement,magnesium potassium phosphate cement was prepared by sintering magnesium oxide and potassium dihydrogen phosphate with composite retarder.The effects of different n(Mg)∶n(P)(2∶1,3∶1,4∶1) on the microstructure,hydration behavior and mechanical properties of magnesium potassium phosphate cement were systematically studied.The performance differences between magnesium potassium phosphate cement and ordinary Portland cement after high temperature heat treatment were compared and analyzed.The results show that when n(Mg)∶n(P) is 3∶1,the hydration reaction of potassium magnesium phosphate cement is the most sufficient,forming a dense matrix structure,and the compressive strength at room temperature is increased to 44.6 MPa.After heat treatment at a lower temperature,the strength of magnesium potassium phosphate cement is significantly reduced due to the decomposition of potassium struvite,the hydration product of magnesium potassium phosphate cement.After high temperature heat treatment at 1000 ℃,magnesium potassium phosphate cement is sintered to form a dense matrix structure,and its high temperature residual compressive strength tends to be stable.The strength retention rate of residual strength is higher than that of Portland cement,showing better high temperature stability.

Effect of different dispersants on the properties of magnesium citrate sol

Sui Jipeng, Si Chaowei, You Jiegang, Guo Jinda, Feng Dong, Zhang Xiaofang, Hou Qingdong

2026, (3): 205-209. doi：10.3969/j.issn.1001-1935.2026.03.004

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Colloid agglomeration is an important factor restricting the application of sol binder in refractory materials.In this paper,magnesium citrate (MC) sol was prepared by using anhydrous magnesium citrate and light burned magnesium oxide powder as raw materials,polyethylene glycol (PEG),sodium tripolyphosphate (STP) and sodium dodecyl benzene sulfonate (SDBS) as dispersants.The effects of citric acid solution concentration (0.2-0.8 mol·L^-1) and dispersant and its addition amount (0-0.4%,weight percentage) on the stability of magnesium citrate sol were studied.The results showed that with the increase of the concentration of citric acid solution,the Zeta potential value decreased gradually,while the conductivity,viscosity and solid mass fraction of MgO increased gradually,and the stability of the sol showed a decreasing trend.The sol prepared by 0.7 mol·L^-1 citric acid solution was superior to other samples in terms of stability and viscosity.The order of the dispersion effect of the three dispersants from high to low is :SDBS > STP > PEG,and SDBS reduces the particle size of the magnesium citrate sol,and the absolute value of the Zeta potential increases,which significantly improves the stability of the colloid.The optimal addition amounts of PEG,STP,and SDBS are respectively 0.2%,0.1%,and 0.05%.

Effect of nano-Fe₂O₃ addition level on the hydration resistance of magnesia-calcia (MgO-CaO) clinker

Han Haopeng, Luan Jian, Pan Bo, Wang Chunyan, Zang Weinan, Yang Zhitao, Qi Ruitong, Zhao Chenyang, Pei Jiaying

2026, (3): 210-215. doi：10.3969/j.issn.1001-1935.2026.03.005

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In order to investigate the effects of nano-Fe₂O₃ on the hydration resistance and other properties of magnesia-calcia materials,dolomite powder and light-burned magnesia were used as the main raw materials.Nano-Fe₂O₃ powder was added,an anhydrous resin served as the binder,the mixtures were pressed at 150 MPa,and then sintered at 1,650 ℃ for 3 h to prepare magnesia-calcia (MgO-CaO) clinker specimens with a CaO content of 30 wt%.The effects of nano-Fe₂O₃ addition (0,2,4,6,and 8 wt%) on the properties of the clinkers were examined.The results show that at 1,650 ℃,nano-Fe₂O₃ can react with CaO in the magnesia-calcia clinker to form the low-melting phase Ca?Fe₂O₃,which facilitates grain rearrangement and growth and thus promotes sintering; however,an excess of this low-melting phase impairs high-temperature strength.With increasing nano-Fe₂O₃ content,the amount of Ca₂Fe₂O₃ increases,the bulk density rises,the apparent porosity decreases,and hydration resistance improves.The thermal-shock resistance first decreases and then increases:when the Fe₂O₃ addition is less than 2 wt%,enhanced densification makes thermal stresses harder to relieve,leading to a decrease in strength retention; when the addition exceeds 2 wt%,the generated low-melting phase together with micropores helps to alleviate thermal stresses,resulting in higher strength retention.When the nano-Fe₂O₃ addition is 2 wt%,the magnesia-calcia clinker exhibits the best mechanical properties while its hydration resistance is significantly improved.

Study on the Anti LiF Corrosion Performance of LaAlO₃ Material

Zhang Chengcheng /Fan Wenjun, Wu Qi, Xin Wenbin, Deng Yongchun, Liu Zhongxing, Zhao Erxiong

2026, (3): 216-220. doi：10.3969/j.issn.1001-1935.2026.03.006

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In order to find materials that can effectively resist the erosion of LiF electrolyte in rare earth fluoride molten salt electrolysis system,high-purity La₂O₃ and Al₂O₃ powders with a mass ratio of 1∶1 were first subjected to secondary calcination at 1150 ℃ for 4 hours in an air atmosphere to synthesize high-purity single-phase LaAlO₃ powder;Subsequently,a binder polyvinyl alcohol solution was added to the powder,and a LaAlO₃ crucible sample was prepared by heat treatment at 1600 ℃ for 4 hours;Load LiF powder into LaAlO₃ crucible samples and conduct corrosion resistance tests at 950 ℃ for 2 hours.The corrosion resistance of LaAlO₃ material to molten LiF was studied.The results showed that the erosion depth of the LaAlO₃ crucible sample was only about 30 μ m,the matrix structure was not damaged,and the LaAlO₃ material did not significantly diffuse into the molten LiF; LaAlO₃ and LiF are still the main phases in the interface reaction products between molten LiF and crucible samples.Therefore,LaAlO₃ material exhibits significant corrosion resistance to molten LiF electrolyte and has the potential to be used as a crucible material for rare earth fluoride molten salt electrolysis.

Influence of lithium feldspar content on erosion-resistant coating performance for the sintering of layered oxides

Su Yuming, Wang Yilong, Zhu Zishuo, Yang Lianti, Liu Qinghua, Qing Da, Wang Jian, Wu Feng, Han Lu

2026, (3): 221-226. doi：10.3969/j.issn.1001-1935.2026.03.007

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To address the issue of structural pulverization of cordierite-mullite system crucibles in high-temperature alkaline environments,a Li₂O-Al₂O₃-SiO₂-TiO₂ high-temperature erosion-resistant coating was developed by using tabular alumina,zircon sand,Guangxi white mud,and titanium dioxide as raw materials and adjusting the glaze slurry formula by introducing spodumene at mass fractions of 0,25%,30%,35%,and 40%.The coating was sprayed onto a mullite-cordierite substrate to prepare a densified erosion-resistant coating.The results showed that the spodumene in the coating enhanced the crucible's erosion resistance by promoting the formation of mullite crystal columns encapsulated by the liquid phase formed by leucite and β-quartz.Additionally,the sodium aluminosilicate phase interface reaction layer formed on the coating surface during the sintering of the cathode material precursor further improved the crucible's erosion resistance.Moreover,the crucible with a 25% (w) spodumene introduction in the coating formula achieved a composite strength of 14.3 MPa,which was higher than that of crucibles with other coating formulas.The apparent porosity of the substrate was reduced by 18.5% compared to the sample without spodumene introduction.After 30 high-temperature cycles,the substrate structure remained intact without any signs of crack propagation.This coating technology can extend the service life of the crucible by more than three times,providing an economically viable and engineering-applicable solution for the interface protection of high-corrosion cathode material sintering equipment.

Research on the Preparation of Yttrium Sol-Yttria Shell for TiAl Alloy Investment Casting

HUANG Hong, HU Haitao, GUO jian, DING Xianfei, NAN Hai, JIN Haipeng, YE Lei

2026, (3): 227-231. doi：10.3969/j.issn.1001-1935.2026.03.008

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This study systematically investigates the influence of powder-to-liquid ratio on slurry viscosity and coating performance in a yttrium sol-Y₂O₃ mold system while elucidating the mechanism through which calcination temperature affects mold strength.The comprehensive properties of the shell mold were validated through TiAl alloy blade casting trials.Results demonstrate that slurry viscosity increases exponentially with powder-to-liquid ratios ranging from 3.0 to 4.4,exhibiting three characteristic stages:slow growth (3.0-3.5),accelerated growth (3.5-4.0),and dramatic surge (>4.0),attributable to the evolving proportion between flocculated clusters and free liquid phase.Slurries with powder-to-liquid ratios of 3.2-3.8 achieve optimal balance between high solid content and coating performance,forming uniform and dense face coats.When calcination temperature reaches 1150℃,the mold attains a peak flexural strength of 9.2 MPa (representing a 48.4% enhancement compared to 950 ℃)due to reduced porosity and formation of crystalline bridges between Y₂O₃ particles.Centrifugally cast Ti-48Al-2Nb-2Cr alloy blades exhibited complete mold filling with merely 5 μm interfacial reaction layer and absence of burn-on or inclusion defects.This research provides a high-performance shell mold solution with significant engineering implications for precision casting of TiAl alloys.

The characteristics of typical mechanical stove and the design and selection of refractory materials

Fan Mingming, Wang Hanyu, Li Ming, Sun Yutong, Wan Jianqiang, Wang Bingwen, Wang Fengyu, Zhan Huasheng

2026, (3): 232-238. doi：10.3969/j.issn.1001-1935.2026.03.009

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This article provides an overview of the characteristics of typical mechanical grate furnaces and the application of refractories in China.Based on the typical damage of refractories,standardization has been conducted on structural modularization and refractory selection of furnace walls.The practice has verified that the modularization of furnace wall and the application of air-cooling and water-cooling technology can effectively solve the problems of deteriorating incinerator operating conditions caused by increasing heat value of the waste.

Mechanism Analysis and Control of Stopper Rod Clogging in Continuous Casting of GCr15 Bearing Steel

Yang Chengwei, Lei Changkun, Wang XianghongHu, Tianzeng, Ren Bo, Wang Enhui, Hou Xinmei

2026, (3): 239-244. doi：10.3969/j.issn.1001-1935.2026.03.010

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Stopper rod clogging represents the primary constraint on operational stability during bearing steel continuous casting.This study focuses on post-service Al₂O₃-C stopper rods from GCr15 bearing steel continuous casting.The clogging layers were analyzed using XRF and SEM techniques,revealing an average clogging thickness of 2.61 mm,with Al₂O₃,CaO,and MgO as primary constituents.The interaction between the decarbonized layer of the stopper rod and non-metallic inclusions in molten steel generates a metamorphic layer composed of calcium aluminosilicate,calcium magnesium aluminate,and spinel,characterized by a porous microstructure.The zirconia layer formed through thermal dissociation of zirconium silicate effectively impedes molten steel infiltration into the decarbonized layer.The overlying Nodules deposits on zirconia predominantly exhibit an interpenetrating microstructure of calcium magnesium aluminate,spinel,calcium aluminate,and steel matrix,where calcium magnesium aluminate manifests as porous agglomerates while calcium aluminate demonstrates spheroidal morphology.Based on systematic analysis of clogging formation mechanisms in stopper rods,targeted countermeasures were formulated to mitigate clogging phenomena.

Test system for melting temperature of continuous casting mold powder based on machine vision technology

Wang Jiangtao, Liu Ke, Dong Dianmin, Li Xiaorui, Liu Yiran

2026, (3): 245-248. doi：10.3969/j.issn.1001-1935.2026.03.011

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In order to solve the accuracy for measured results,the intuitiveness、intelligence and non-contact for the measured process for melting temperature of continuous casting mold powder.Based on machine vision technology,a system for melting temperature of continuous casting mold powder is designed and realized.The system establishes a reasonable model of the visual system to eliminate the interference of high temperature scene light,selects a high-exposure industrial camera to image the sample clearly,uses image analysis algorithm to extract effective information from the image,and tracks and recognizes the sample in real time through image tracking technology.The field test shows that the system for melting temperature of continuous casting mold powder based on machine vision can complete the measurement for melting temperature accurately,and the repeatability error is within ±20 ℃,which meets the requirements of YB/T 186 for melting temperature of continuous casting mold powder.

Current status and improvement measures of rh furnace immersion tubes

Jiang Sheng, Zhu Changjiang, Lu Jiuchang

2026, (3): 249-253. doi：10.3969/j.issn.1001-1935.2026.03.012

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In order to improve the service life of the immersion tubes used in the RH furnace,the existing problems of the immersion tubes during operation such as the falling off of casting material,the burning damage of steel lining,the explosion of welds and brick body,and the low efficiency of thermal maintenance,etc.) were analyzed.Through the implementation of comprehensive measures such as the optimization of process parameters,the improvement of the structure of immersion tubes,and the adjustment of thermal maintenance,the average service life of impregnated tubes has been significantly increased from 105 to 118 furnace times,and the failure rate has been reduced by 15%.The consumption of refractory spraying materials per ton of steel has been reduced by 0.05 kg,and the problems of casting falling off and weld cracking have been effectively solved.The cost of smelting production and consume of refractory material have been significantly reduced ,and reliable technical support have been provided for stable production of high-value-added silicon steel and electrical steel by the implementation of comprehensive measures in the workshop.

Preparation and application status of mullite-based porous materials

Liu Jinhua, Tian Xuekun, Yin Tianpei, Yan Donghong, Zhao Fei, Luo Zhongtao, Li Suping, Liu Xinhong

2026, (3): 254-260. doi：10.3969/j.issn.1001-1935.2026.03.013

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Mullite has a high melting point,a low thermal expansion coefficient,excellent thermal shock resistance,and relatively low thermal conductivity.Therefore,porous mullite-based materials are widely used in high-temperature thermal insulation,catalysis,filtration,and other fields.The research and application status of porous mullite,mullite fiber-based ceramics,and mullite aerogels,based on the differences in the morphology and structure of mullite,were reviewed in this manuscript.Furthermore,the future research directions and application prospects of mullite-based porous materials are discussed,aiming to provide references and insights for the future research.

Research progress of industrial solid waste-based porous ceramics

Wu Yanting, Huang Xuejin, Lei Huicong, Gao Yabo, Huang Zhong

2026, (3): 261-266. doi：10.3969/j.issn.1001-1935.2026.03.014

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Industrial production and urbanization have generated a large amount of industrial solid waste,which has brought a serious damage to the human ecological environment.How to utilize them as resources is one of the current research hotspots in the field of materials.Solid waste,being rich in elements such as Al and Si,as raw materials to prepare porous ceramics can not only significantly reduce the production cost of porous materials for high-temperature industries and constructions,but also provide an effective way to high-value utilization of solid waste resources,showing the important economic,environmental and social benefits.This article reviews the current research status of fly ash,steel slag,red mud and other solid wastes in the preparation and application of porous ceramics in recent years.

Research Progress on Coating Formation Performance of Refractories for Cement Rotary Kilns

Qingze Chen, Chao Qu, Huicong Lei, Haijun Zhang, Shaowei Zhang

2026, (3): 267-270. doi：10.3969/j.issn.1001-1935.2026.03.015

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The performance of refractories in terms of kiln skin formation is crucial for the smooth production of cement in rotary kilns.During the cement clinker sintering process,refractories are subjected to a combination of thermal stresses,shear forces,and chemical corrosion from the clinker.Therefore,the kiln skin performance of refractories plays a pivotal role in extending the service life of cement rotary kilns and reducing energy consumption.In this paper,the current research status of coating formation performance of commonly used refractories in cement rotary kilns is reviewed.The advantages and limitations of different refractory materials are summarized,and the key issues and future research directions are outlined.The aim is to provide a reference for improving the coating formation performance and application of refractories in cement kilns.

Research Progress on CMAS Erosion Resistance of Rare Earth Zirconate Ceramics with Different Configuration Entropies

Wang Xiaobo, He Zhiyong, Zhang Yanxiang

2026, (3): 271-276. doi：10.3969/j.issn.1001-1935.2026.03.016

Abstract ( ) PDF (1096KB)( )

This paper systematically analyzes the core failure mechanisms of traditional YSZ thermal barrier coatings under high-temperature service environments.Its failure is mainly associated with key factors such as high-temperature phase transformation and calcium-magnesium-aluminum-silicate (CMAS) erosion,making it increasingly unable to meet the stringent service requirements of advanced aero-engines.Rare earth zirconate ceramics,endowed with high thermal expansion coefficient,low thermal conductivity,and excellent CMAS erosion resistance,have emerged as highly promising new alternative materials.The paper comprehensively reviews the research progress of rare earth zirconate ceramics with different configurational entropies in the field of CMAS erosion resistance.It simultaneously elaborates on their intrinsic mechanisms of CMAS erosion resistance and clarifies the regulatory role and influence laws of configurational entropy on the material’s erosion resistance performance.Finally,it is pointed out that future research should focus on investigating erosion kinetics under dynamic service conditions and further improving the composition-property prediction model.Through deepening basic research and technological breakthroughs,solid support will be provided for the engineering application of such materials in advanced aero-engines,promoting their transformation from laboratory research to practical engineering applications.