Li Chongjun, Ma Boxin, Huo Xiaoxu, Hao Zhibiao. The State and Catalytic Graphitization of Boron in Carbon/Carbon Composites[J]. Journal of Materials Engineering, 1998, 0(12): 3-7.
The boron doped short carbon fiber reinforced furfuryl-acetone resin derived glassy carbon matrix C/C composites were fabricated by addition of powdered carbon and boron.By means of XRD,XPS,the state of boron,boron oxide and the effects of their catalystic graphitization in C/C were studied;the affecting factors to graphitization degree including temperature,catalytic kinds and catalyst amount were also analysed.In result,boron exists in C/C in the state of solid solution;through such catalytic mechanisms and attracting electron to break bond,replacing carbon atom to eliminate defects,the glassy carbon and fibrous carbon,which are more non graphitizable,can get higher graphitization degree.On condition that temperature is 2100℃,boron is less than 5.0wt%,the graphitization degree of glassy carbon matrix C/C is up to 82%,which is increased by 11% than that of 2500℃ graphitized C/C without catalyst It is shown that boron can decrease graphitization temperature sharply.
Wu Fengjun, Li Jianping, Li Weiguang. A Study of MCrAlX Coating Contained Ta[J]. Journal of Materials Engineering, 1998, 0(12): 8-10.
A NiCoCrAlYTa coating was developed to improve the service temperature of MCrAlY coating,and static oxidation test,cyclic oxidation test,hot impact test,and microstructure analysis of specimen coated with the coating was performed. The results show that the cyclic oxidation life of the NiCoCrAlYTa coating at 1150℃ can increases 80h compared with NiCrAlY coating,and that its service temperature can be improved by adding appropriate amount of Ta.
Zhao Ping, Gao Shengji, Chen Rui, Dong Bin, Shen Baoluo, Tu Mingjing. Influence of Pressure in Squeeze Casting on Tensile Strength of the Metal Matrix Composites[J]. Journal of Materials Engineering, 1998, 0(12): 11-14.
A serial of pressure maintaining for solidification has been used to fabricate M/Al(mullite fibre/aluminum) composites,and the influence of the pressure on the tensile strength of the composites has also been investigated. The results indicate that the pressure significantly effect the dimension of the noninfiltrated defects and the tensile strength of the composites.
Tan Songting, Zhang Mingqiu, Rong Minzhi, Zeng Hanmin, Li Baoen. Study on Properties of Metal Fibre Filled Polymer Composites[J]. Journal of Materials Engineering, 1998, 0(12): 15-17,38.
Electrical conductive composites were fabricated using ABS, HIPS and PP as matrix resins filled with Cu fibre and stainless steel fibre. The effects of metal fibre contents and compounding conditions on electrical and mechanical properties in the elctrical conductive composites have been studied. The results indicate that the key to prepare electrical conductive composites with superior properties is higher L/D ratio of metal fibres and well-dispersion of the fibres in matrix.
Yan Chong, Xiao Hanning, Yang Qiaoqin, Li Shaolu, Peng Wenqin. Effects of the Content of Carbon on the Structure and Properties of C-SiC-TiC-TiB2 Composite[J]. Journal of Materials Engineering, 1998, 0(12): 18-20.
Effects of the content of carbon on the structure and properties of carbon/ceramic composite prepared by in-situ synthesis were studied. It is found that the bending strength of the composite decreases with the increase of carbon content. The sintering temperature of the composite should be higher to obtain a dense carbon/ceramic composites when the carbon content increases.
Zhang Lanting, Wu Jiansheng, Wada Hitoshi. Unidirectional Solidification of Ti3Al+Ti5Si3 Dual Phase Alloy by Floating Zone Method[J]. Journal of Materials Engineering, 1998, 0(12): 21-24.
Attempts are made on the growth of unidirectionally solidified Ti3Al+Ti5Si3 dual phase alloy by optical floating zone method. The microstructures of the as grown alloys are closer to the equilibrium state than that of the as cast alloy. The microstructure of the as grown is not uniform along the radial direction. The alignment of Ti5Si3 phase along the growing direction is observed in alloys grown at high growth rate.
Zhang xiangwu, Pan Yi, Shen Lie, Yi Xiaosu. Power Properties of Polyethylene/Carbon Black Conductive Composite[J]. Journal of Materials Engineering, 1998, 0(12): 25-28,34.
The power properties of the self-limiting heating strip that is made of polyethylene/carbon black composite were studied at various environments. The ability that the heating strip adjusts its power output with the variety of the ambient temperature automatically is related to the heat transfer. The working temperature of the heating strip is controlled by the voltage used. The power-voltage characteristic is determined by the heat transfer(δ) and the characteristic of the heating strip itself (R0,αT). The power-voltage characteristic can be improved by heat treatment considerably. The assembling of the heating strip can not influence the power-voltage characteristic but can change the power value.
Tan Weidong, Guo Hongquan, Song Jun, Ouyang Hui. Research on Low Cycle Fatigue Properties of High Strength Steel GC4 in Corrosive Environments[J]. Journal of Materials Engineering, 1998, 0(12): 29-31.
Low cycle fatigue properties of aeronautical high strength steel GC4 in corrosive environments are researched in this paper. The results of test are useful for determining airplane working life in corrosive environment.
Wang Rongming, Zhang Shaowei, Li Chunzhi, Yan Minggao. Microstructure Study on the Fatigue Creep and Hydrogen Embrittlement[J]. Journal of Materials Engineering, 1998, 0(12): 32-34.
Microstructures of the low expansion superalloy GH907 have been studied. The major strength γ phase becomes irregular and the platelet ε phase splits into pieces in the alloys after fatigue creep. However,the microstructure of the alloy remains stable when filled with hydrogen,which indicates excellent anti-hydrogen embrittlement of the alloy. The plasticity and tensile properties of the alloy decrease a little from the decreased binding strength between the grain boundary phase and the matrix by the hydrogen segregation at the grain boundaries.
Zhao Aiguo, Zhong Peidao, Xi Niansheng, Tao Chunhu. Crack Analysis of Static Vanes in a High Pressure Turbine[J]. Journal of Materials Engineering, 1998, 0(12): 35-38.
The characteristics and the formation of the cracks in static vanes in a high pressure turbine have been investigated. It has been shown experimentally that the cracks are characterized by typical thermal fatigue. The high test temperature and the uneven temperature distribution as well as the bad cooling condition at the exhaustion edge are responsible for fracture of vanes. The measures to prevent vane failure have been put forward in this paper.
Han Jiecai, Dong Shiyun, Zhang Xinghong, Du Shanyi. Present Status of the Manufacture Processings for Metal/Ceramic Graded Coatings[J]. Journal of Materials Engineering, 1998, 0(12): 39-42.
The existing manufacture processings for metal/ceramic graded coatings, including the processing techniques, characteristics and applications are summarized. More over, the key problems existed in the processings are presented in this paper.
Li Baoshan, Niu Yushu, Zhai Xiujing, Zhai Yuchun, Shao Zhongcai. Development,Properties and Applications of Porous Metals(Ⅱ) Properties and Applications of Porous Metals[J]. Journal of Materials Engineering, 1998, 0(12): 43-47.
Properties of foamed metals,including mechanical properties,energy absorbing characteristics,damping properties,acoustical properties,conductivities,electromagnetic shielding properties,permeability etc.,are described systemly. Their applications,such as impact energy absorbers,silencers,filters,flame arresters,heaters and heat exchangers,constructional materials,catalysts and porous electrodes,electromagnetic shielding materials,and their complex materials with others etc.,have been reviewed,so as to indicate the wide range of their usefulness.
