E. S. Markena, E. B. Kachanov. An Improvement of Melting Technology of Steel ЭИ928[J]. Journal of Materials Engineering, 1993, 0(6): 1-2.
In order to decrease nitride inclusion the melting technology of steel ЭИ928 has been changed.The new technology has decreased the nitride inclusion of 50%.
Yu Zhicheng. Damage Coefficient of Composites Delamination[J]. Journal of Materials Engineering, 1993, 0(6): 3-5.
Damage coefficient of delamination k=(1-E*/E0) is one of the important parameters in calculating interlaminar fracture toughness Gc.In NASA standard (NASA RP 1092), k was taken approximately as 0.16,that if this approximation value is still suituble for the most resins in China is a question to be discussed.This paper is deal with this question.The analysis results had shown that to compare the frature toughness Gc of compsites with different resin matrix of China,k should be calculated respectively,rather than use k=0.16 directly by NASA stundard.The critical failure modulus of composite laminates were tested and measured in this study,the critical failure modulus was less than the modulus when the composite laminate was delaminated completely.
Xu Shiyi, Lü Wensheng, Su Qingyou. Study on the Microstructure of Martensite and Bainite Obtained by the Austempering and the Properties of 30CrMnSiNi2A Steel[J]. Journal of Materials Engineering, 1993, 0(6): 7-9,5.
This paper deals with the relationship between the micrestructure of martensite and bainite obtained by austempering and mechanical properties of 30CrMnSiNi2A steel.The experiment relevant show that the adoption of the relatire content martensite and bainite controlled by the proper austempering can bring a remarkable rise of tensite-tonghness of the steel of this kind.Thus,it is a great practical significance in improving theretiability of aircraft.
Guo Chaoqi. The Method of Reckoning up Titanium Alloy Density form its Element Contents[J]. Journal of Materials Engineering, 1993, 0(6): 10-11,19.
The method of reckoning up titanium alloy density from ite alloy element contents is introduced.It is possible to simplify the physical method of specific weight to be measured.
Deng Bo, Zhang Rongwu, Yang Yurong. Effects of Heat Treatments on Structure and Mechanical Properiets of GH4169 Alloy[J]. Journal of Materials Engineering, 1993, 0(6): 12-15.
GH4169 alloy is a aged-hardening alloy that is widely used in aircraft engine parts. In this peper,the effects of three heat treatments on structure and mechanical properties of GH4169 alloy have been studied. Higher tensile strength at room temperature and high temperature may be obtained by DA treatment.The materials treated by HST have more δ phases. Therefore. they have better notch rupture properties.The NT treatment is for the improvement of stress rupture life.
Zhang Qing, Mao Qingzhu. Off-White Nonelectromagnetic Shielding Effect Antistatic Coating-PUB[J]. Journal of Materials Engineering, 1993, 0(6): 20-22,2.
The PUB which is a kind of off-white nonelecttomagnetic shielding effect antistutic coating with good properties is developed.It consists of polyurethane resin,off-white electroconductive pigment B2 and solvents.Some of factors that influence electrical conductivity of the film is discussed.
Liu Runguang, Liu Haihua, Lü Yan, Tai Longgen, Liu Jinhai, Yan Bin, Liu Dongbo, Yang Wenyi. The Technology of Superplastic Isothermal Precision Forging of 2618A Alloy Hinge Joint of the Movement Barrel[J]. Journal of Materials Engineering, 1993, 0(6): 26-29.
In this paper according to the character of the geometric structure and the technical requirement of the movement berrel hinge joint, the process of superplastic isothermal precision forging is proved to be the best forming way.The metal flow situation of the new process performed in a 5×104kN hydropress and the character of the die structure are introduced simply.Through a series of experiments,some of processing perameters such as blank size and lubricant are gained.The better demformation temperature is about 450℃.The better strain rate is about 5.9×10-4s-1～1.7×10-2s-1.Finally, the reason of producing faults in precision forgings and the way of getting rid of the faults are analysed.The quality of the preciaion forgings produced by the new process is raised greatly,meanwhile the economic benefit of the new process obvious.
Li Jichen. Homogeneity Assessment of Certified Reference Material Sample of ZT3 Titanium Alloy[J]. Journal of Materials Engineering, 1993, 0(6): 32-33.
In this paper the variance analysis and mean uniformity method are used to check the homogeneity of titanium alloy certified reference material.The statistic results for the two elements of aluminium and sillcon show good homogeneity of the reference material.Mathematical statistics has been played an important role in the developement of reference materials.
Liu Yongning, Zhou Huijiu. The Instantaneous Deformation and Inertia Force of a Series of High Velocity Charpy Impact Test[J]. Journal of Materials Engineering, 1993, 0(6): 34-36.
The instantaneous deformation and inertia force of a series of high velocity Charpy impact test are described in the paper.The first stress pulse on the back side of specimen is positive and it increases as the increase of loading rate from 5 to 40m/s.The force exerted on the specimen is divided into two parts:the dynamic force and the inertia force which changes following the Sin law. The influence of inertia force can he eliminated by balancing the values of peak and valley on the stress ourves.For brittle state the inertia force must be considered.There is a phase difference between the stress signals on the pendulum edge and specimen.
Zhang Yanhua, Chen Bingsen. Quantitative Analysis of Morphology Characteristics in Fractographic[J]. Journal of Materials Engineering, 1993, 0(6): 37-39.
In this paper the quantitative analysis methods of fracture surface roughness and configurational characteristics of the fracture profile are presented.These methods could be appropriate for analysing fracture processes and developing high fracture ressistant materials.
Zhou Suhong Yao jixang, Yao Bei. Inactivation Analysis on the Shaft of Steering Plumbing Arm of Trucks[J]. Journal of Materials Engineering, 1993, 0(6): 42-43,41.
The shaft of steering plumbing arm of the truck inactivated before it was operated less than two monthes.The microscopic and macroscopic view analysis of the fracture surface showed that the reason of the fracture a distortion caused by accidental loading at the Instantaneous moment.
Yang Yuchun, Jin Hong. Rare Earth-Nonferrous Materials and Their Developments[J]. Journal of Materials Engineering, 1993, 0(6): 46-48,45.
The effects, the applied value,the present status of applications and the development prospects for rare earths or their compounds as added elements or alloy composition in Al-, Mg-, Ti-, Cu-based alloys and Ni-, Co-based superalloys (except for function materials) have been systematically introduced in this paper. It’s pointed that there is practical significance to spread the applications of rare earths in cast Al alloys,and it is very important for opening up the new ways of applications to carry out foundational research.
