Thermal Barrier Coatings(TBCs)technology is key to improving the service temperature and the productivity of aircraft engines.The performance and failure life of TBCs are strongly influenced by surface integrity and m...Thermal Barrier Coatings(TBCs)technology is key to improving the service temperature and the productivity of aircraft engines.The performance and failure life of TBCs are strongly influenced by surface integrity and microstructure.Therefore,recognizing failure mechanisms and developing effective surface treatment processes are crucial for further improving the reliability and durability of TBCs.This paper explains the primary reasons for TBC failure,emphasizing on how integrity of surface and interface influences interfacial oxidation,high-temperature erosion,and Calcium-Magnesium-Alumina-Silicate(CMAS)corrosion.Furthermore,this paper completely and rigorously evaluates the research status of TBCs surface treatment processes,including the characteristics and effects of various processes,and describes the requirements and goals of pretreatment and post-treatment.In addition,a potential direction for the development and application of TBCs surface treatment is suggested.展开更多
Nano-SiO2/polypropylene composite was prepared by melt-blending process. The nano-SiO2 particles were organized by wet process surface treatment with silane coupling agent KH-570. The effect of mass fraction of nano-S...Nano-SiO2/polypropylene composite was prepared by melt-blending process. The nano-SiO2 particles were organized by wet process surface treatment with silane coupling agent KH-570. The effect of mass fraction of nano-SiO2 particles and dosage of KH-570 on the toughening and strengthening of PP matrix were investigated based on the fractography of impact notch and the analysis of crystal structure by X-ray and dispersive structure of nano-SiO2 by TEM. Results show that the impact and flexural strength and modulus of the composite are improved obviously with low loading of nano-SiO2 （3 wt%-5 wt%）, and the izod impact strength of PP increases twice with 4 wt% nano-SiO2. The nano-SiO2 particles treated can disperse into the matrix resin, which has evident heterogeneous nucleation effects on the crystallization of PP. The optimal toughening and strengthening effects of PP matrix can be obtained when the content of nano-SiO2 and KH-570 are 4 wt% and 3 wt%, respectively.展开更多
This paper is aimed to show the influence of initial chemical pretreatment prior to subsequent plasma activation of aluminum surfaces.The results of our study showed that the state of the topmost surface layer（i.e.th...This paper is aimed to show the influence of initial chemical pretreatment prior to subsequent plasma activation of aluminum surfaces.The results of our study showed that the state of the topmost surface layer（i.e.the surface morphology and chemical groups）of plasma modified aluminum significantly depends on the chemical precleaning.Commonly used chemicals（isopropanol,trichlorethane,solution of Na OH in deionized water）were used as precleaning agents.The plasma treatments were done using a radio frequency driven atmospheric pressure plasma pencil developed at Masaryk University,which operates in Ar,Ar/O_2 gas mixtures.The effectiveness of the plasma treatment was estimated by the wettability measurements,showing high wettability improvement already after 0.3 s treatment.The effects of surface cleaning（hydrocarbon removal）,surface oxidation and activation（generation of OH groups）were estimated using infrared spectroscopy.The changes in the surface morphology were measured using scanning electron microscopy.Optical emission spectroscopy measurements in the near-to-surface region with temperature calculations showed that plasma itself depends on the sample precleaning procedure.展开更多
Friction pair coatings are highly susceptible to failure in corrosive marine environments.To enhance their service performance,this study focuses on the friction pairs in the main shaft transmission of offshore wind t...Friction pair coatings are highly susceptible to failure in corrosive marine environments.To enhance their service performance,this study focuses on the friction pairs in the main shaft transmission of offshore wind turbines and investigates the wear and corrosion resistance of different surface treatment processes.A wear theory model is developed on the basis of dynamic changes in the contact area to predict wear under dry friction and corrosive conditions.The results indicate that the Interzinc B coating results in the best overall performance in terms of friction,wear,and corrosion resistance.Rough and high-hardness surfaces increase the friction coefficient,whereas Zn powder and ZnO adhesive not only produce less abrasive debris but also form a micro/nanoparticle self-lubricating mechanism,reducing surface wear.Compared with the traditional zinc spraying process,the friction coefficient can be increased by 28.4%,whereas the wear amount can be reduced by 76.2%.The release of Zn^(2+)and the oxidation reaction mechanism enhanced the self-healing ability of the passive film,improving its anticorrosion ability.The maximum error between the finite element analysis of coating wear and the test results is only 6.26%,which verifies the accuracy of the wear theory model and provides guidance for the precise design of wind turbine transmission friction pairs.展开更多
基金the National Natural Science Foundation of China (Nos.52075362 and 51975399)the Central Government Guides Local Foundation for Science and Technology Development,China (Nos.YDZJSX2022A020 and YDZJSX2022B004).
文摘Thermal Barrier Coatings(TBCs)technology is key to improving the service temperature and the productivity of aircraft engines.The performance and failure life of TBCs are strongly influenced by surface integrity and microstructure.Therefore,recognizing failure mechanisms and developing effective surface treatment processes are crucial for further improving the reliability and durability of TBCs.This paper explains the primary reasons for TBC failure,emphasizing on how integrity of surface and interface influences interfacial oxidation,high-temperature erosion,and Calcium-Magnesium-Alumina-Silicate(CMAS)corrosion.Furthermore,this paper completely and rigorously evaluates the research status of TBCs surface treatment processes,including the characteristics and effects of various processes,and describes the requirements and goals of pretreatment and post-treatment.In addition,a potential direction for the development and application of TBCs surface treatment is suggested.
基金Funded by the Commission of Science Technology and Industry for National Defense(No.93013)
文摘Nano-SiO2/polypropylene composite was prepared by melt-blending process. The nano-SiO2 particles were organized by wet process surface treatment with silane coupling agent KH-570. The effect of mass fraction of nano-SiO2 particles and dosage of KH-570 on the toughening and strengthening of PP matrix were investigated based on the fractography of impact notch and the analysis of crystal structure by X-ray and dispersive structure of nano-SiO2 by TEM. Results show that the impact and flexural strength and modulus of the composite are improved obviously with low loading of nano-SiO2 （3 wt%-5 wt%）, and the izod impact strength of PP increases twice with 4 wt% nano-SiO2. The nano-SiO2 particles treated can disperse into the matrix resin, which has evident heterogeneous nucleation effects on the crystallization of PP. The optimal toughening and strengthening effects of PP matrix can be obtained when the content of nano-SiO2 and KH-570 are 4 wt% and 3 wt%, respectively.
基金the Czech Science Foundation(Project No.104/08/02290)the Czech Ministry of Industry and Trade(Project CZ.1.03/5.1.00/12.00010)the Czech Ministry of Education(Project MSM0021622411)
文摘This paper is aimed to show the influence of initial chemical pretreatment prior to subsequent plasma activation of aluminum surfaces.The results of our study showed that the state of the topmost surface layer（i.e.the surface morphology and chemical groups）of plasma modified aluminum significantly depends on the chemical precleaning.Commonly used chemicals（isopropanol,trichlorethane,solution of Na OH in deionized water）were used as precleaning agents.The plasma treatments were done using a radio frequency driven atmospheric pressure plasma pencil developed at Masaryk University,which operates in Ar,Ar/O_2 gas mixtures.The effectiveness of the plasma treatment was estimated by the wettability measurements,showing high wettability improvement already after 0.3 s treatment.The effects of surface cleaning（hydrocarbon removal）,surface oxidation and activation（generation of OH groups）were estimated using infrared spectroscopy.The changes in the surface morphology were measured using scanning electron microscopy.Optical emission spectroscopy measurements in the near-to-surface region with temperature calculations showed that plasma itself depends on the sample precleaning procedure.
基金supported by the National Natural Science Foundation of China(No.51875382)the Fundamental Research Program of Shanxi Province(No.202203021222206)+2 种基金the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(No.2022L275)the Research startup fund project of Taiyuan University of Science and Technology(No.20222048)the Outstanding doctoral award fund for coming to Jin(No.20232050).
文摘Friction pair coatings are highly susceptible to failure in corrosive marine environments.To enhance their service performance,this study focuses on the friction pairs in the main shaft transmission of offshore wind turbines and investigates the wear and corrosion resistance of different surface treatment processes.A wear theory model is developed on the basis of dynamic changes in the contact area to predict wear under dry friction and corrosive conditions.The results indicate that the Interzinc B coating results in the best overall performance in terms of friction,wear,and corrosion resistance.Rough and high-hardness surfaces increase the friction coefficient,whereas Zn powder and ZnO adhesive not only produce less abrasive debris but also form a micro/nanoparticle self-lubricating mechanism,reducing surface wear.Compared with the traditional zinc spraying process,the friction coefficient can be increased by 28.4%,whereas the wear amount can be reduced by 76.2%.The release of Zn^(2+)and the oxidation reaction mechanism enhanced the self-healing ability of the passive film,improving its anticorrosion ability.The maximum error between the finite element analysis of coating wear and the test results is only 6.26%,which verifies the accuracy of the wear theory model and provides guidance for the precise design of wind turbine transmission friction pairs.
