Hu Wangyu, Guan Hengrong, Sun Xiaofeng, Li Shizhuo, Masahiro Fukumoto, Isao Okane. Residual Stress of ZrO2-Ni Coatings Prepared by Plasma Spraying[J]. Journal of Materials Engineering, 1999, 0(2): 3-5.
The surface and average stress were determined for the plasma sprayed ZrO2-Ni coatings with various Ni content, the former was determined by X ray stress analysis method, the latter by curvature measurement stress analysis method.The obtained results showed a fair agreement between these stresses, and they were small tensile stress.The average residual stress and spraying temperature for two-layer, three-layer, four-layer and six-layer coatings were estimated by the measured curvature.It implied the gradad structure contributed little effect to reduce the residual stress of coatings.The average spraying temperature was in agreement with the practical operated conditions.
Han Yong, Wu Huizhuo. The Phase Structure of ZnS Bulk Materials Prepared by Chemical Vapor Deposition[J]. Journal of Materials Engineering, 1999, 0(2): 6-8,11.
The infrared crystal ZnS bulk materials were prepared by chemical vapor deposition.The phase structure of ZnS was respectively analyzed with XRD and TEM, and their infrared transmittance was measured using IR.The results are as follows.The phase structure of ZnS deposited at temperature range from 550℃ to 700℃ and H2S/Zn mole flow ratio 0.5～20 is mainly sphalerite, and there exited a few wurtzite structure with layer morphology in ZnS.The content of wurtzite structure tends to increase with increasing deposition temperature and H2S/Zn mole flow ratio, which decreases infrared transmittance of ZnS.The formation of wurtzite structure is related to partial pressure of sulphur in deposition atmosphere.Therefore, ZnS bulk materials should be deposited at lower temperature and H2S/Zn mole flow ratio to obtain unitary sphalerite structure.
Ma Hongtao, Yang Yunlin, Zhang Baiqing, Xi Jukui, Zhang Ruisheng. Effects of Rare-earth Elements on Superplasticity of MB26 Magnesium Alloy[J]. Journal of Materials Engineering, 1999, 0(2): 9-11.
The effects of rare-earth elements on superplasticity of MB26 alloy was studied in this paper, and its acting mechanism was also discussed.
Zhang Jianfeng, Zheng Qiang, Cao Suhua, Yi Xiaosu. Influence of Electron Beam Irradiation on Resitivity of High Density Polyethylene/Carbon Black Conductive Composites[J]. Journal of Materials Engineering, 1999, 0(2): 12-15,18.
Influence of electron beam irradiation on the resitivity of carbon-black loaded high density polyethylene(HDPE/CB) conductive composites were studied.The results showed that resitivity increased with increasing temperature.The PTC intensity of composites irradiated at room temperature was higher than that irradiated at melting temperature under the same irradiation dose.For two different irradiation conditions, NTC effect disappeared when irradiation doses were over 200kGy.The changes of resitivity were related to crystallinity and crosslinking of polyethylene by irradiation.
Wang Xicheng, Cao Wei, Tian Jie, Mo Xiaohong. Synthesis of Highly Oriented PZT Ferroelectric Thin Film[J]. Journal of Materials Engineering, 1999, 0(2): 16-18.
A zirconyl nitrate instead of Zr alkoxide has been used as the source of Zr element to get a transparent and stable PZT precursor solutions by sol-gel technology.The PZT sol was spin-coated onto Pt/Ti/SiO2/Si substrate.Meanwhile, lead-titanate (PT) film was as a interlayer film between PZT film and the substrate.After annealing by RTA method, high oriented texture with good electrical properties have been obtained in the PZT thin film.
Yang Xue, Dai Yongyao, Zhao Guangwen, Jin Dongming. A Study of the Ceramic Matrix Composites Reinforced by Carbon Fibers[J]. Journal of Materials Engineering, 1999, 0(2): 19-21,24.
One of the problems with the use of CVD techniques to densify the ceramic matrix reinforced by fibers is the difficulty in achieving complete infiltration. This is due to “bottle-neck” effects in which the CVD matrix closes off small pores,which in turn blocks access to larger pores To this end a new method,position control CVD(PCCVD),to overcome the difficulty above mentioned is presented. By means of controlling the reaching position of react gases and the heating position in matrix,the close pores in the matrix densified by PCCVD technique have not come into being from start to finish. There are only a few,if any,pores in matrix and the density of C/SiC composites manufactured by PCCVD technique can achieve 96% of theoretical density.
She Dongling, Xu Hongqing, Dong Yan, Dai Nanrong, Li Zhanyi. A Study of the Recycling of BCl3 during CVD Boron Fiber[J]. Journal of Materials Engineering, 1999, 0(2): 22-24.
The recycling of boron trichloride(BCl3) during boron fibre production may be realized by the reaction between Cl2 and B4H10 included in BCl3 which was retrieved during CVD boron fibre production.
Wang Weidong, Wang Yong, He Yanling, Li Honglin. An Investigation on the Interface between the Coating and Base Metal of Welded Joints of Enamel Pipelines(Ⅱ)[J]. Journal of Materials Engineering, 1999, 0(2): 25-27.
An investigation on the welded enamel pipelines is taken via TEM in this paper.Before welded the enamel coating was of amorphous state, and some nitrogen atoms infiltrate in the ferrite of the matrix. This may cause the matrix brittle and may decrease the binding force between the coating and the matrix.After welded, the coating becomes crystal in HAZ, and Al2O3, SiO2 are formed.This may decrease the corrosion resistance of the coating.
Liu Junyou, Shi Zhongliang, Gu mingyuan, Tao Xiaodong. A Study of its Microstructure of Silicon Particle Reinforced Zinc Matrix Composite[J]. Journal of Materials Engineering, 1999, 0(2): 28-29,34.
The new method-rheologic mixed multiple melts has been put forward and silicon particle reinforced zinc matrix composite has been prepared by this method in the paper.It has been found that silicon itself has a lot of defects and the interfacial precipitated products between silicon particles and ZA27 matrix has been analyzed, observed by TEM.
Zhao Haofeng, Han Shiping. Development and Application of Special Casting Techniques in Production of MMCs[J]. Journal of Materials Engineering, 1999, 0(2): 30-34.
This paper deals with application and development of special casting techniques such as stiring casting, squeez casting, gas pressing casting, centrifugal casting,suction pouring investment casting, spray casting, continuous casting and directional solidifing in production of MMCs.These techniques are filled with new contents while they promote the application of MMCs.
Zhang Zheng. Feature and Application of Friction Stir Welding[J]. Journal of Materials Engineering, 1999, 0(2): 35-36.
Friction stir welding releases the process from restriction to rotationally symmetrical bodies. A tool positioned above the center line of the joint is rotated fast enough to produce thermal plasticity and moved along the joint. Friction stir welding, unlike fusion welding, involves no melting and resolidification and therefore does not create the cast microstructure, comparatively lange HAZ potential distortion,and residual stress typical of fusion welds. The artical overviews the advantages and current status of friction stir welding.
Ru Jigang, Yi Linna, Zhang Lushan. A Study of the Ultra High Strength Aluminium Alloy Heat Treatment Process[J]. Journal of Materials Engineering, 1999, 0(2): 37-39.
The solution treatment and different ageing process has been studied. The results show that DSA treatment can improve obviously combination of strength and corrosion resistance of the ultra-high-strength aluminium alloy. The priciple of improving the strength and corrosion resistance of the alloy by DSA treatment has been discussed. The surface and average stress were determined for the plasma sprayed ZrO2-N.
Hao Shanshan, Liu Haiping, Wang Xiaohong, Feng Zixiu, Hao Mengyi, Li Jingui. Deposition of the NiCrAlY Coating by Vacuum Arc Ion Plating[J]. Journal of Materials Engineering, 1999, 0(2): 40-42,47.
The technique depositing the NiCrAlY coating by vacuum arc ion plating was investigated in this paper.The component deviation between the NiCrAlY coating and the target was analyzed.The effect of the technique parameter on the microstructure of the coating was researched.Finally, the effect of the vacuum heat treatment on the diffusion between the NiCrAlY coating and the matrix was discussed.
Tao Chunhu, Xi Niansheng. Application Investigation of Concurrent Engineering in Failure Analysis[J]. Journal of Materials Engineering, 1999, 0(2): 43-47.
Failure analysis has developed in a new stage in which it has characteristics of integrity, system, objectiveness, urgency, society and law.These new characteristics requires introduction of Concurrent Engineering (CE) into Failure Analysis (FA).It has pointed out that application of CE in FA is feasible.Essential factors of implement and practical ways for application of CE in FA have been discussed in this article.The application of CE would provide FA a novel mode of thinking and analysis to achieve the FA aims as “conclude correctly, understand clearly in mechanism, reappear by simulation, draw inferences about other cases from one instance”.
