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The definition of J-integral of interfacial crack was introduced. The three-point bending tests were carried out to obtain the critical loading
values when the interfacial crack initiation occurred between coatings and substrates. The finite element analysis (FEA) was
adopted to analyze the stress distribution in the specimens and compute the J-integral of the interfacial crack between LX88A coating and Chinese Q345 steel. The results showed that the average value
of critical J-integral is 0.70 N/m, which can be taken as the fracture parameter to evaluate the interfacial fracture behavior for the
three-point bending specimens of LX88A coating/Q345 steel system.
Supported by Tianjin Natural Science Foundation (No.08JCYBJC09100), New Teacher Research Fund for the Doctoral Program of
Higher Education of China (No.20070056096) and New Century Outstanding Talented Person Plan of China.
XU Lianyong, born in 1975, male, Dr. 相似文献
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The fracture behavior of a ceramic reinforced metal-base coating prepared by high velocity arc spraying (HVAS)technology in three-point bending test was studied.Moreover,finite element analysis(FEA)was adopted to analyze the stress distribution in the crack front.It can be found that the crack norrnal to the interface in the coatings occurred at the location where a fixed moment of force was reached.So the critical moment can be taken as thecoating cracking criterion,which was confirmed by FEA results.In addition,the stress levels at three different locations where cracks occurred near the interface are almost the same.The results will provide reference for the design of coatings and the structure integrity evaluation of coating/substrate systems. 相似文献
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管理学校,校长每天都要面对一大堆需要处理的问题:部门工作拖延了,学生旷课了,老师和领导闹矛盾了……很多校长陷入这样的事务堆,累得心力交瘁。其实,这是一种错位的管理,校长应该有更重要的事情去做。校长不妨变换一下思维方式。学会从终点来思考问题。 相似文献
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High-Temperature Corrosion of Protective Coatings for Boiler Tubes in Thermal Power Plants 总被引:4,自引:0,他引:4
High-temperature corrosion is a serious problem for the water-wall tubes of boilers used in thermal power plants. Oxidation, sulfidation and molten salt corrosion are main corrosion ways.Thereinto, the most severe corrosion occurs in molten salt corrosion environment. Materials rich in oxides formers, such as chromium and aluminum, are needed to resist corrosion in high-temperature and corrosive environment, but processability of such bulk alloys is very limited. High velocity electric arc spraying (HVAS) technology is adopted to produce coatings with high corrosion resistance. By comparison, NiCr (Ni-45Cr-4Ti) is recommended as a promising alloy coating for the water-wall tubes, which can even resist molten salt corrosion attack. In the study of corrosion mechanism, the modern material analysis methods, such as scanning electron microscopy ( SEM ), X-ray diffractometry (XRD) and energy dispersive spectrometry (EDS), are used. It is found that the corrosion resistances of NiCr and FeCrAl coatings are much better than that of 20g steel, that the NiCr coatings have the best anti-corrosion properties, and that the NiCr coatings have slightly lower pores than FeCrAI coatings. It is testified that corrosion resistance of coatings is mainly determined by chromium content, and the microstructure of a coating is as important as the chemical composition of the material. In addition, the fracture mechanisms of coatings in the cycle of heating and cooling are put forward. The difference of the thermal physical properties between coatings and base metals results in the thermal stress inside the coatings. Consequently, the coatings spall from the base metal. 相似文献
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The definition ofJ-integral of interfacial crack was introduced.The three.point bending tests were carried out to obtain the criticaI lOading values when the interfacial crack initiation occurred between coatings and substrates.The finite element analysis(FEA)was adopted to analyze the stress distribution in the specimens and compute the J-integral of the interfaciaI crack between LX88A coating and Chinese 0345 steel.The results showed that the average value of critical J-integral iS 0.70 N/m.which can be taken as the fracture parameter to evaluate the interfaciaI fracture behavior for the three-point bending specimens of LX88A coating/Q345 steel system. 相似文献
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