Zhang Erlin, Yang Bo, Zeng Songyan, Li Qingchun, Ma Mingzhen. Formation Mechanism of TiC in Al-Ti-C System[J]. Journal of Materials Engineering, 1998, 0(2): 3-5,29.
The mechanism of reaction synthesis TiC in Al/TiC composites prepared by direct reaction synthesis(DRS)has been investigated in detail by use of quenching experiment, XRD and SEM. The results have shown that the reaction mechanism is a solution-precipitation mechanism, in which titanium dissolves into melted aluminium and reacts with carbon atom at the surface of carbon to form TiC, and then TiC particle precipitates out of the melt. It has also been shown that the processing of reaction synthesis TiC can be devided into three stages:melting of aluminium powder in the preform, formation and resolution of Al3Ti phase in the melted aluminium and the synthesis of TiC particles In the end, a mechanism model of DRS to prepare Al/TiC has been established.
Liu Zhengtang, Zhu Jingzhi, Song Jianquan, Zheng Xiulin. Deposition Rate of GeXC1-X Films Prepared by Reactive Sputtering[J]. Journal of Materials Engineering, 1998, 0(2): 6-8.
In this paper, GeXC1-X films were prepared by radio frequency magnetron reactive sputtering in CH4/Ar in a wide range of processing parameters. The effect of processing parameters on the deposition rate has been studied. Experiment results showed that the deposition rate decreased sharply when the gas flow ratio CH4/Ar increased to a certain number. With the increase of the radio frequency power, the deposition rate increased. A maximum deposition rate occurred varying with the gas pressure The relationship between the film thickness and the deposition time seemed different in targetpoisoning and non-target-poisoning.
Wang Qingru, Zhang Qingling, Chen Yuwen, Chu Junpeng. Superplasticity and Applications of the Ti-15-3 Alloy[J]. Journal of Materials Engineering, 1998, 0(2): 9-12.
The superplastisity of the Ti-15-3 titanium alloy sheet in annealed and cold rolled conditions has been investigated. The peak values of m appear at 700℃ in both conditions up to 0.4. Elongation is 260%. The cold rolled foil can form complex parts at 700℃ by superplastic forming and the excellent mechanical properties have been obtained. This part has been used on the satellites.
Ma Yongqing, Gao Hongtao. Microstructure Design and Properties of Cr-Ni Metastable Austenite Matrix Wear Cast Iron[J]. Journal of Materials Engineering, 1998, 0(2): 13-16.
The microstructure design of Cr-Ni metastable austenite matrix wear cast iron was accomplished by metallurgical theories. The microstructure of this new wear cast iron was austenite matrix with networked eutectic carbide M7C3 by the sand model casting, and the surface hardness was improved because friction induced martensite, and then, the wear resistance of this cast iron was very fine. The metastable austenite matrix of this cast iron was relatively stable during middle temperature region, and the carbide M23C6 was precipitated during high temperature region. But the change of austenite composition was little because of the partial solvation of eutectic carbide Therefore, this wear cast iron is also of good thermostability.
Li Botao, Han Minfang. Research of Silicon Nitride Ceramics by the Process of Reacting to Fill up and Resintering[J]. Journal of Materials Engineering, 1998, 0(2): 17-20.
The silicon nitride ceramics gotten by the process of reacting to fill up and resintering were researched in the paper. As a result, the silicon nitride ceramics with high density and low sintering shrinkage was fabricated by way of silicon powder replacing part of silicon nitride powder, nitriding process of constanting temperature at 1150℃,1250℃,1350℃,and then resintering in free pressure.
Liu Guoli, Ge Laichun, Chen Shenchuan, Mi Jiawei, Hong Runzhou. Investment Casting of Cylinder Baffle for Aircraft Application[J]. Journal of Materials Engineering, 1998, 0(2): 21-23.
A cylinder baffle is one of the key parts of aircraft engine It has large size and thin wall. And high quality is required. An investment casting technique which the casting forms in vaccum and solidifies under pressure is developed. With this technique, a cylinder baffle for aircraft application that has precise configuration, good surface finish and high metallurgical quality is produced.
Liu Dongxun, Ouyang Shuang. Effect of Hot-melt Film Impregnation on Mechanical Properties of Composite[J]. Journal of Materials Engineering, 1998, 0(2): 24-25,46.
It has been discussed that hot-melt film impregnating G803PV with 3234 resin affected the mechanical properties of the composite, flexural strength, flexural modulus and interlaminar shear strength, the retention of them. It has been shown that the hot wet resistance of the composite was improved by using the method of hot-melt film impregnation.
Yao Haibiao, Xie Changsheng. MJS Rapid Prototyping Technology in Fabricating Metal Porous Materials[J]. Journal of Materials Engineering, 1998, 0(2): 26-29.
This paper introduces a new rapid prototyping technology——Multiphase Jet Solidification(MJS). The design of MJS system and the process of the prototype parts are analyzed and discussed. The post-treatment process are designed. The microstructure and properties of Ni60 metal porous material fabricating by MJS process are given.
Zhang Yong, Lin Junpin, Chen Guoliang, Li Guanxing, Ren Yonggang, Zhang Zhishen. The Densification for the Sinew of Silicon Nitride Ceramic Foam under Nonencapsulation HIP[J]. Journal of Materials Engineering, 1998, 0(2): 30-32.
After nonencapsulation HIP treated, the sinews of pressless sintered silicon nitride ceramic foam are densified, its microhardness and modulus are increased greatly, at the same time, the ceramic foams's opening porosity decreased a little, however, its compressive strength increased much more. The XRD phase analyse shows that HIP facilitate the phase transformation of α-Si3N4 to β-Si3N4, this transformation stimulate the diffusion activity of the atoms The theory analysis confirms that the sinew densification mechanism is that the pore shrink is by vacancy migration from the pore to the sinew surface under the driving force of HIP pressure.
Wu Yucheng, Deng Zonggang. Electroless Co-deposited SiCp Ceramic-Composite Coating[J]. Journal of Materials Engineering, 1998, 0(2): 33-37.
The electroless deposited technology was used to make SiCp combined with Ni(P)alloy, and SiCp ceramic-composite coatings were fabricated Results exposed that SiCp distributed uniformally into Ni(P)matrix, in which the ceramic-phase played obvious strengthen ing roles; compared with Ni(P)alloy coating, SiCp ceramic-composite coatings owned higher hardness, thermal stability and oxidization resistance.
Chen Mingan, Zhang Xinming. New Approaches for Processing of Rapidly Solidified Particulate Reinforced Aluminium Matrix Composites by Double-roller Method[J]. Journal of Materials Engineering, 1998, 0(2): 38-40.
For the preparation of particulate reinforced aluminium matrix composites with strongly refined microstructure, uniformly distributed particles in the matrix, and good bond and very little reaction between particles and matrix materials, two approaches, by blowing particles into the melt puddle between the twin-roller and by ejecting the composite melt produced by in situ contact reaction into gap between the twin-roller, have been proposed based on rapid solidification of aluminium alloys by double-roller method The potential advantages of the composites prepared by the methods were presented.
Xi Shoumou, Wang Shan, Zhang Jianguo. Critical Nitrogen Potential of 38CrMoAlA and 40CrNiMoA Steel[J]. Journal of Materials Engineering, 1998, 0(2): 41-43.
In the paper, the weight gain method are used to measure nitrogen potential in ammonia atmosphere. The critical nitrogen potential without net nitride or white layer in the micro section of 38CrMoAlA and 40CrNiMoA steel are between 0.32%N～0.39%N when the piece of steel are saturatly intrided at 515℃ in 15h.
Zhang Qingan, Gao Jiasheng, Chen Huifen, He Yizhu. Mechanisms of Fracture of a Mash Seam Welded Joint in IF Steel[J]. Journal of Materials Engineering, 1998, 0(2): 44-46.
The mechanisms of fracture of a mash seam welded joint in interstitial free(IF)steel have been studied. It was found that a crack forms by means of microvoid accumulation in the welded core zone at the bottom of a welding-off defect and extends to a coarse-grain zone.Then the crack extends on cleavage planes in coarse grains Finally, the joint fractures by means of the separation of slip planes in a partial recrystallized zone.
Wang Jianqiang, Chang Xinchun, Hao Yunyan, Hou Wanliang, Hu Zhuangqi. Real-time Monitoring and Intelligent Control for Spray Forming Process[J]. Journal of Materials Engineering, 1998, 0(2): 47-49.
On-line diagnostic technique that are currently available for monitoring processing parameters, such as PCSV-P probe, high-speed cinematography, off-axis holographic cinematography, infrared thermal imaging, phase Doppler particle analysis, are compared and evaluated. In addition, intelligent control systems containing fuzzy logical control and artificial neural networks are also reviewed and discerned for their usefulness, in making spray atomization and deposition a more controlled process.
