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Ablation Mechanism of HfC-HfO2protective coating for SiC-Coated C/C Composites in an Oxyacetylene Torch Environment

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Journal of Materials Science & Technology 2017年第10期33卷 1195-1202页

作者： Yang Yang Kezhi Li Guanxi Liu Zhigang Zhao State Key Laboratory of Solidification Processing Carbon/Carbon Composites Research Center Northwestern Polytechnical University Xi'an 710072 China

To prevent the C/C composites from ablation, HfC-HfO2 protective coating was prepared by supersonic atmospheric plasma spraying. The morphology and microstructure of HfC-HfO2 coating were characterized by X-ray diffraction and scanning electron microscopy. The ablation resistance test was carried out by an oxyacetylene torch. The results show that the as-prepared coating is dense with little pinholes and crack free. The elements Hf, C and O were uniformly distributed in the cross-section. After ablation for different time, the mass ablation rate fluctuated along with the change of ablation time. The ablation process of the surface coating could be divided into rapid oxidation and solid state sintering stages. During ablation, an Hf CxOy-HfO2 transitional layer was generated in the coating, which resulted from the active oxidation of Hf C. After cooling, some microcracks were observed on the surface of coating, and the structure of cross-section was broken, which were due to the phase transition of HfO2.

关键词： Carbon/carbon composites Supersonic atmospheric plasma spraying protective coating Ablation property

Influence of protective coating at High Temperature on Surface Quality of Stainless Steel

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Journal of Iron and Steel Research(International) 2014年第2期21卷 202-207页

作者： Xiao-meng ZHANG Lian-qi WEI Peng LIU Sen WANG Shu-feng YE Yun-fa CHEN State Key Laboratory of Multi-phase Complex Systems Institute of Process EngineeringChinese Academy of Sciences School of Engineering Technology China University of Geosciences

A ceramic matrix coating for minimizing steel loss of stainless steel at high temperatures was prepared by handled air-spraying technique, and the influence of coating on surface quality of stainless steel was mainly investiga ted in laboratory. Experimental results showed that the protective coating reduced the oxidation of stainless steel by more than 91% and minimized high temperature scaling and also enhanced steel surface quality. The scales of coated specimen were removed completely and the scales of uncoated specimen were partly residual on the surface after cool ing process. Mn-rich and Fe-rich zones were found in the oxides. The Cr2 O3 found in scales came from the underlying stainless steel and formed a Cr rich layer along the spalled surface.

关键词： protective coating oxidation loss surface quality stainless steel

Hydrothermal synthesis and corrosion behavior of the protective coating on Mg-2Zn-Mn-Ca-Ce alloy

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Progress in Natural Science:Materials International 2016年第6期26卷 590-599页

作者： Dan Song Guanghui Guo Jinghua Jiang Liwen Zhang Aibin Ma Xiaolong Ma Jianqing Chen Zhaojun Cheng College of Mechanics and Materials Hohai University Department of Material Science and Engineering North Carolina State University School of Materials Science and Engineering Southeast University Jiangsu Collaborative Innovation Center of Advanced Micro/Nano Materials & Equipment Nanjing University of Science & Technology

protective coatings were synthesized on the Mg-2Zn-Mn-Ca-CeMg alloy through the hydrothermal method with de-ionized water as the reagent. The coatings were composed of Mg hydroxide, generally uniform and compact.Hydrogen evolution tests and electrochemical tests in the Hanks’ solution demonstrated that the Mg（OH）;coatings effectively decreased the bio-degradation rate of the Mg alloy substrate. Microstructure observation showed that the coating formation on the secondary phases was more difficult than that on the α-Mg matrix,which led to micro cracks and pores on the secondary phases after drying. Over synthesizing time, the coating layer on secondary phases gradually becomes more compact and uniform. Meanwhile, owing to the thicker and more compact coatings, the corrosion resistance and protective efficiency were significantly improved with longer synthesizing time as well.

关键词： protective coating Mg alloy Hydrothermal synthesis Microstructure Corrosion resistance

Preparation and Characterization of Low-melting Glasses Used as Binder for protective coating of Steel Slab

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Journal of Wuhan University of Technology(Materials Science) 2013年第2期28卷 380-383页

作者：仉小猛魏连启 XU Haiwei WANG Shuhua YE Shufeng WANG Xiaojing ZHOU Xun CHEN Yunfa State Key Laboratory of Multi-phase Complex Systems Institute of Process Engineering Chinese Academy of Sciences Graduate University of Chinese Academy of Sciences

The low-melting phosphate glass was prepared for production of glass binders for protective coating of steel slab. Effects of different O/P ratios on glass structures and properties were analyzed. Differential thermal analysis （DTA） and infrared spectroscopy （IR） techniques were applied for low-melting glass binder. It was found that the glass transition temperature（T） was about 300 ℃ and softening temperature（T1） was about 480 ℃. The choice of O/P ratio was very important to the glass transition and softening temperatures. When more P=O bonds existed in the glass networks, P-O-P bond angle was deformed with decreasing of the ratio of O/E The coatings could adhere to the substrates instantaneously at 800 ℃ when the content of binder exceeded 3wt%. The optimal content of glass binder was 5wt%.

关键词： low-melting glasses binders steel slab protective coating

Study　of　organic　silicon　resin　protective　coating　with　high　laser　damage　threshold　for　KDP　crystal

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Chinese Journal of Lasers 1994年第5期3卷 469-474页

作者： TANG Yongxing ZHANG Weiqing ZHOU Weiping ZHU Congshan(Shanghai Instifute of Optics and Fine Mechanics,Academia Sinica,P. O. Box 800 - 216, Shanghai 201800, China) Shanghai Inst of Optics and Fine Mechanics Academia Sinica Shanghai China

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关键词： laser damage of coating protective coating

Experimental Study on Wax protective coating for Wet Deep Silicon Etching Processes

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Journal of Beijing Institute of Technology 2006年第3期15卷 306-310页

作者：蒋剑良 ULRICH Hilleringmann School of Information Science and Technology Beijing Institute of Technology Beijing 100081 China Fachgebiet Sensorik University of Paderborn D-33098 Paderborn Germany

In order to protect the finished structures on the front side during deep silicon wet etching processes, the wax coating for double-sided etching process on the wafer is studied to separate the aforementioned structures from the strong aqueous bases. By way of heating and vacuumization, the air bubbles are expelled from the coating to extend the protection duration. The air pressure in the sealed chamber is 0.026 7 Pa, and the temperature of the heated wafer is 300℃. Two kinds of the wax are used, and the corresponding photos of the etched wafer and the protection times are given. In 75 ℃ 10 % KOH solution, the protection duration is more than 8 h.

关键词： deep silicon etching potassium hydroxide etchant protective coating

In-situ chemical conversion film for stabilizing zinc metal anodes

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Journal of Energy Chemistry 2022年第10期31卷 387-393,I0009页

作者： Hao Fu Qing Wen Pei-Yao Li Zhen-yu Wang Zhen-jiang He Cheng Yan Jing Mao Kehua Dai Xia-hui Zhang Jun-chao Zheng School of Metallurgy and Environment Central South UniversityChangsha 410083HunanChina Engineering Research Center of the Ministry of Education for Advanced Battery Materials Central South UniversityChangsha 410083HunanChina School of Mechanical Medical and Process EngineeringQueensland University of TechnologyBrisbaneQueensland 4001Australia School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450001HenanChina College of Chemistry Tianjin Normal UniversityTianjin 300387China School of Mechanical and Materials Engineering Washington State UniversityPullmanWashington 99164United States

Zinc metal anodes face several challenges,including the uncontrolled formation of dendrites,hydrogen evolution,and corrosion,which seriously hinder their application in practice.To address the above problems such as dendrite formation and corrosion,we present a simple and applicable immersion method that enables in situ formation of a zinc phytate(PAZ)coating on the surface of commercial Zn flakes via a substitution reaction.This protective coating mitigates corrosion of zinc flakes by the electrolyte,reduces the interfacial impedance,and accelerates the migration kinetics of zinc ions.Besides,this method can preferentially expose the(002)crystal plane with strong atomic bonding,which not only improves the corrosion resistance of the zinc flake,but can also guide the parallel deposition of zinc ions along the(002)crystal plane and reduce the formation of dendrites.Benefiting from the above advantages,the PAZ@Zn‖Cu half-cell has shown over 900 cycles with average coulombic efficiency(CE)of99.81%at 4 mA cm^(-2).Besides,the PAZ@Zn‖PAZ@Zn symmetric cell operate stably for>1000 h at5 mA cm^(-2)and>340 h at 10 mA cm^(-2).Furthermore,we demonstrated that this in situ chemical treatment enables the formation of a robust,well-bound protective coating.This method provides insights for advancing the commercialization of zinc anodes and other metal anodes.

关键词： Zinc anode Phytic acid protective coating Dendrites Surface modification Corrosion resistance

High Temperature Corrosion and Protection of Titanium Alloys and TiAl Intermetallics

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Rare Metals 1996年第3期15卷 203-207页

作者：唐兆麟王福会吴维中科院金属腐蚀与防护所金属腐蚀与防护国家重点实验室辽宁沈阳

High temperature corrsoion and protection of trtanium alloys and TiAl intermetallics are reviewed, andsome suggestions on the development of protective coatings are put forward.

关键词： TiAl intermetallics Titanium alloys High temperature corro-sion protective coating

Role of Calcium Magnesium Aluminate in Carbon-containing Bricks for Steel Ladle

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China's Refractories 2021年第1期30卷 23-30页

作者： GAO Jianying WOHRMEYER Christoph DETEUF Cyrille Imerys Aluminates(China)Co. Ltd.Tianjin 300457China Imerys Aluminates Puteaux 92800France

Calcium magnesium aluminate,with the commercial name of MagArmour,is a synthetic material consisting of 70 mass%Al_(2)O_(3),20 mass%MgO and 10 mass%CaO,approximately.It is characterized by porous microstructure,intergranular aluminates phases and micro-crystalline spinel.Since globally launched in 2017,MagArmour has been successfully applied to various carbon-containing refractories serving for steel refining process.Lots of cases have demonstrated the role of MagArmour in enhancing the service life of carbon containing bricks for ladle lining.The benefits embody in formation of protective coating on hot surface,relief of drilling corrosion in joint positions,and elimination of grooves or cracks caused by mechanical stress concentration.In addition,MagArmour is effective in protecting graphite from deep oxidization so as to be capable of replacing the metallic or carbide anti-oxidants in carbon-containing bricks entirely.By means of chemical analysis and microstructural dissection,postmortem investigations on the used MgO-C bricks from both metal and slag zones of 120t steel refining ladle were conducted to clarify the working mechanism of MagArmour.The formation of protective coating on hot face is attributed to the dissolution of micro-crystalline spinel into contacting slag,which changes the slag chemistry so as to enhance viscosity.The improvement in corrosion/erosion resistance is highly related to the porous microstructure and dispersive aluminates.As well known,evaporation of Mg,Al and SiO,and/or internal migration,occurs in MgO-C bricks at elevated temperatures.The gaseous phases are absorbed by MagArmour particles due to the high surface area of porous microstructure and condense as corresponding oxides.These oxides react with the intergranular calcium aluminates forming liquid phase.With increasing temperature,the liquid phase seeps into the matrix under capillary force.The increased liquid amount improves the flexibility of the matrix and thus releases the internal stresses concentration resulting from

关键词： calcium magnesium aluminate MagArmour protective coating flexibility oxidation resistance