Papers by Author: Dang Sheng Xiong

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Authors: Jun Liu, Dang Sheng Xiong, Bin Li
Abstract: Integration of smart materials such as field-responsive fluid, i.e. Electro-rheological (ER) , magneto-rheological (MR) and shear thickening fluids (STFs), into armor protective materials, may probably solve the problem between its portability and protective performance. The wide applications of three fluids are described in brief in this paper, and research developments (especially STFs’ in detail) of armor protective materials strengthened by utilizing three fluids or chemical reaction material are summarized. Analysises are made of the questions faced by these composites researches. The foreground is talked about in the end.
Authors: He Min Jing, Bo Wang, Dang Sheng Xiong, Yin Geng Xu, Jun Jie Wang, Peng Zhan Wang, Guang Hui Liu, Yan Zhang
Abstract: The use of P92 is becoming more and more widespread in high temperature steam pipe of super-ultracritical power station boilers, it’s key material for the manufacture of boiler’s four main pipes. The properties of P92 are closely related with its microstructure, and the microstructure of P92 has strong relationship with its’ composition and hot processing technology. Three types of P92 with different composition have been prepared. The relationship of delta ferrite between composition, smelting and heat forging process has been investigated for these three samples. The results show that the delta ferrite can be avoided by the adjustment of composition and making process, the delta ferrite will occurred in the matrix of P92 which without delta ferrite before heat treatment if the heat temperature exceed 1200°C , the delta ferrite existed in P92 ingot matrix resulted from the composition cannot be eliminated by hot working and heat treatment.
Authors: Jing Yao Zhang, Zhou Yu, Dang Sheng Xiong
Abstract: Effect of three kinds of RE ion (Y3+, Nd3+, La3+), which added separately in the Ni-P electroless deposition bath, on coating micro-structure and property such as microhardness, wear and corrosion resistance was investigated. Optimization of organization structure and property of coating attributed to RE-added was analysed by means of ICPM, XRD, SEM and micro-sclerometer, wear testing machine. The results show that the coating has still amorphous structure but higher of phosphorus content due to RE, which added in the bath can make coating grains smaller and more compact. At the same time, improved microhardness, wear and corrosion resistance of coating are observed with RE-added properly. The effect of Y3+ is most remarkable among three RE ions. When the concentration of Y3+ in the bath is 0.04g.L-1, the microhardness, wear loss and corrosion rate in 10% H2SO4 solution of coating is 606HV, 4.9572mg and, respectively.
Authors: Yong Kang Zhang, Jian Liang Li, Dang Sheng Xiong, Yong Kun Qin
Abstract: The nickel-based boron nitride composite coatings were prepared by reversing pulse electro-deposition. The mechanical properties and friction behavior of the coatings at high temperature were tested by using Al2O3 ceramic ball at high temperature friction-testing machine. The results show that the surface micro-hardness of the coatings increases with the addition of BN powder. Meanwhile, the friction coefficient and wear rate of specimens decreases. Especially when the BN addition is 1.5g/L the composite coatings present a minimum of friction coefficient and wear rate. In optimum process parameters, the friction coefficient of the coatings is about 0.2 at room temperature and 0.4-0.5 at 600°C. In addition, the friction and wear properties were significantly improved by plating Ni transition layer plated between substrate and composite coating.
Authors: Jian Liang Li, Hang Li, Dang Sheng Xiong, Yu Juan Ji, Yong Kun Qin
Abstract: In this paper an adaptive Ni-Mo-Al-Ag-BN composite coating was deposited by plasmaspraying. Its tribological property from 20°C-600°C were evaluated by using high temperature tribometer. Scanning electron microscopy and Raman spectroscopy were used to characterize the coating and corresponding wear tracks to determine the lubrication mechanisms. The result shows that the friction coefficient of the Ni-Mo-Al–Ag-BN composite coating from 200°C to 400°C is about 0.4 and declines very slightly at 600°C . The wear rates of the coating is 2.0×10-4mm3/N*m at 600°C and the downward trend is obvious compared with 400°C. Silver provide lubrication below 400 °C. Ag2MoO4 were formed with the temperature raised, and acted as high-temperature lubricants above 400 °C. Ni-Mo-Al–Ag-BN composite coating established a new lubrication mechanism model at 600°C . It can be concluded that the plasma sprayed Ni-Mo-Al - Ag - BN composite coating can keep good tribological property at wide range of temperature.
Authors: Jing Yao Zhang, Dang Sheng Xiong
Abstract: Ni-P nanocrystalline and amorphous coating were fabricated by electroless deposition technique in the same bath except for varying complexing agent. Heat treatment at lower temperature was carried out to the two kinds of coatings above. The phosphorus content and organize structure of the as-deposited coatings was determined by means of inductively coupled plasma atomic emission spectrometry, X-ray diffractometer and transmission electron microscope. Moreover the effects of heat treatment and structure on microhardness and tribology property of coatings were studied by means of microhardness tester, friction and wear tester and scanning electron microscope. Outstanding tribology property of Ni-P nanocrystalline coating compared with the amorphous one owed to the fine nickel grains with a size of several nanometers. While the proper heat treatment process was found to be responsible for improved property of both coatings.
Authors: Yan Shi, Dang Sheng Xiong, Jian Liang Li
Abstract: In the present study, the poly (vinyl alcohol) (PVA)/graphene oxide (GO) hydrogels were synthesized by the repeated freeze-thaw method. The microstructure of PVA/GO hydrogels was characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM). The effects of GO content, lubrication condition, load and sliding speed on the friction properties of PVA/GO hydrogels were investigated. The results showed that the fracture morphology of PVA/GO hydrogels showed a layered-structure with uniformly dispersed GO sheets in PVA matrix. The friction coefficient of PVA/GO hydrogels decreased with the increase of GO content and sliding speed. With the increase of bovine serum and load, the friction coefficient of hydrogels decreased first and then increased.
Authors: Jie Jiang, Dang Sheng Xiong, Jian Liang Li, Yan Shi
Abstract: Components of space machines often works at high temperature and vacuum, or on other rigour conditions, the traditional liquid lubricant cannot satisfy the requirement. The common solid lubricant is hard to supply between two friction surfaces continuously and it is easily decomposed and failure at high temperature. It is an urgent need to study a new type of lubrication technology. In this paper, the surface of 1Cr18Ni9Ti with high hardness and micro dimples was prepared through laser texturing and plasma molybdenizing/plasma nitriding duplex treatment. The textured surface was coated with MoS2 lubricating film and the friction and wear properties from room temperature to high temperature were evaluated. The results show that the laser surface textured dimples trap hard abrasive particles and reduce the damage to the lubricating film, and thus decrease the wear rate. The optimum dimple density of 7.1% is obtained. At elevated temperature, the wear rate of molybdenized texture or nitrided texture is lower than that of the matrix and single textured surface.
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