Huang Fuxiang. Aviation Metallurgy Industry in USSR[J]. Journal of Materials Engineering, 1990, 0(2): 4-7.
This article introduces briefly some new achievements that the aviation metallurgy industry in USSR has made in recent years in aluminium alloy, titanium alloy, superalloy and porder metallurgy production and application. Their production capability and property level of some alloys are mentioned as well. It will be a help to the future sino-soviet scientific and technological cooperation and exchange.
Wang Rong, Yan Junmin. On Changes of the Microstructure and Mechanical Behavior in ICr11Ni2W2MoV Steel after Long-hour Aging[J]. Journal of Materials Engineering, 1990, 0(2): 8-11.
This paper describes the aging behavior of 1Cr11Ni2W2MoV steel with quenching at 1010℃-1.5h and tempering at 570℃-1.5h air cooling. The experiments show that this steel is sharply embrittled after aging at 250 and 450℃ for 500~1000h. As aging time prolonged up to 4000h at 450℃ the impact tougness increased obviously.
Chen Darning, Kang Mokuang. Significance of Impact Value of Ultra High Strength Steel for Landing Gear of Aeroplane[J]. Journal of Materials Engineering, 1990, 0(2): 12-15.
The notch impact test of ultra high strength 40CrMnSiMoVA steel for landing gear has been carried out by electronic oscillography. The results proved that the bainitic microstructure obtained by isothermally quenching at 300℃ is effective for increasing the impact value of 40CrMnSiMoVA steel.
Xu Yongbo, Zhang Yun, Wang Zhongguang, Hu Zhuangqi. Fatigue and Fracture Behavior of an Aluminium-Lithium Alloy at Ambient and Cryogenic Temperature[J]. Journal of Materials Engineering, 1990, 0(2): 16-18.
An investigation on the fatigue and fracture behavior of an Al-Li-Cu-Mg-Zr 8090-T6 alloy at room (300K) and liquid nitrogen (77K) temperatures has been conducted out. The fatigue and fracture strengths as well as ductilities of the alloy have been found to increase with decreasing temperature. The observations by SEM and TEM reveal that the changes in fatigue and fracture behavior with temperature are considered to associate with the change in the fracture mode.
Hou Ping, Chen Fusheng. Using Double-Factor Variance Analysis to Determine the Effect of Anodizing Time and Voltage on the Durability of Adhesive Bond[J]. Journal of Materials Engineering, 1990, 0(2): 19-20.
This article uses double-factor variance analysis to analyze the adhesive bonded specimen, which were prepared by different phosphoric acid anodizing process, in order to determine the effect on durability of adhesive bond.
He Jiawen, Ma Baotian, Wu Yusheng, Yu Yonghe, J. F. Flavenot. Shot Peening on Torsion Fatigue[J]. Journal of Materials Engineering, 1990, 0(2): 21-23.
The reverse torsion fatigue limit after shot peening and prestrain is higher 20-30% than that of ground one.According to fractography, the specimens fractured near the fatigue limit are caused by normal stress, their fracture surface inclines 45° of the specimen axis.Hardness distributions for shot peened specimen show a softened layer in the subsurface.Compressive residual stress are the main factor in the increase of torsion fatigue limit. Torque prestrain may induce damage or cracks which decrease the reverse torsion fatigue limit of shot peened specimen.
Tang Xinmin. The Practice of Production in the Vacuum Heat Treatment[J]. Journal of Materials Engineering, 1990, 0(2): 24-25.
Some operating problems on the vacuum heat treatment of the high speed tool steel have been discussed and analysed in this paper. The advantages of the vacuum heat treatment in the industrial production will be introduced as well.
Yuan Peibo. Large Sized Vertical Vacuum Quenching Furnace and Its Trial Application[J]. Journal of Materials Engineering, 1990, 0(2): 26-28.
This article describes the structural characteristics of the vertical vacuum quenching furnace designed and manufactured in China. The size of the working space is φ600mm×1500mm. The practice proves that the furnace can meet the technical requirements of heat treatment for the aviation components, titanium alloy parts and some kinds of precise machinery parts.
Ren Rongzhen, Sun Changyi, Gao Shan. Acoustic Emission Characteristics of Tensile Processes in OCr18Ni9Ti/Al Composites[J]. Journal of Materials Engineering, 1990, 0(2): 29-31.
The acoustic emission technique was used to characterize OCr18Ni9Ti/Al composites during tensile processes and unload/reload cycles (Felicity effect). In metal matrix composites as FRP materials, the high count events and Felicity ratio are the criteria of acceptance/rejection.
Li Jichen. Application of F-test Method for standard Sample of Ti Alloy[J]. Journal of Materials Engineering, 1990, 0(2): 32-33.
The homogeneity of aluminium and tin contents in the national standard chemical sample of ZT3 titanium alloy has been indentified by F-test. The contents of aluminium and tin elements were determined by nitrous oxide-acetylene flame atomic absorption spectrometry. The experiment data were obtained repeatedly and treated statistically. The results show that our standards are homogeneous and also conformable to the national class. This investigation will open the new application of mathematical statistics in analysing the identity of chemical standard.
Lin Shuxi. Thermal Analysis on Directionally Solidified Process[J]. Journal of Materials Engineering, 1990, 0(2): 34-37.
In this paper the directional solidification cooling curve of the alloy DZ3 slab was determined by a thermal analysis method and its solidifying parameters of G,R and G/R value have been calculated. The results show that there is a "valley" of G and G/R value in the curve at the distance of 80~ 120mm from the chill plate, accompanied with coarsened dendrite and decreased stress-rupture life. However, when the distance was greater than 120mm the G,G/R value and stress-rupture life arises again and the dendritic size becomes smaller. The reason for the "valley" phenomenon of G nad G/R "valley" will be discussed in the present investigation.
Wang Xueping, Kang Deli, Li Lexin. Fracture Failure Analysis to the I Stage Turbine Blade of the Turbojet WP-7B[J]. Journal of Materials Engineering, 1990, 0(2): 41-43.
In this paper, the fracture failure of the I stage turbine blade of the Turbojet WP-7B during flight has been researched and analysed by microfractographic analysis and microscope observation. The scanning electron microscope (SEM) and transmission electronic microscope (TEM) for fracture surface observation has been used as well. Crack and γ' phase of the material have been observed, and the nature and main reason of such failure have been found. The conclusion is that the crack failure of the I stage turbine blade is a thermo-fatigue crack failure. The proposal of how to avoid such failure to the manufacturer and overhaul department has been put forward and submitted to the relevant organization.
