WANG Hai-dou, XU Bin-shi, LIU Jia-jun, ZHUANG Da-ming. Study on Microstructures and Tribological Performance of Ion Plating Mo Layer[J]. Journal of Materials Engineering, 2005, 0(3): 3-5,29.
In order to enhance the wear-resistance of materials, the multi-arc ion plating technology was employed to prepare the metal molybdenum layer with 3μm thick on the AISI 1045 steel. AFM and SEM equipped with EDX were adopted to observe and analyze the morphologies and composition of surface, cross-section and worn scar of the plating Mo layer. The phase structure was studied by XRD and the bonding strength between Mo layer and substrate was measured by scratching tester. The tribological experiments showed that the Mo layer possessed a good wear-resistance and an excellent anti-scuffing property. The failure mechanism of plating Mo layer was flaking off.
LI Jia-jun, ZHENG Chang-jin, ZHAO Nai-qin, GUO Xin-quan. Study on the Radar Absorbing Composite with Orthogonal-arranged Silicon Carbide Fiber Circuit[J]. Journal of Materials Engineering, 2005, 0(3): 6-9,51.
Radar absorption performances of orthogonal-arranged SiCf circuit/epoxy composite and orthogonal-arranged electroless-nikel-plated SiCf circuit/epoxy composite were studied. The results showed that radar absorption performances of the composites were deeply affected by the distance between SiCf and the rate of mass growth of the nikel coating. As to the former, with the decrease of the distance between SiCf, radar absorption bandwidth and the maximum absorption peak exhibited an enhancement, as though radar absorption effect was weak when the distance was wide(such as 8mm, 6mm); as to the latter, with the increase of the distance or the rate of weight growth, radar absorption performance exhibited an increase and then followed by a decline.
ZENG Yan-ping, ZHANG Mai-cang, DONG Jian-xin, ZHANG Li-na, XIE Xi-shan. Study on Crack Initiation and Propagation Induced by Inclusion in Nickel-base P/M Superalloy[J]. Journal of Materials Engineering, 2005, 0(3): 10-13,17.
In situ tensile and fatigue tests in special designed SEM have been conducted to trace the whole process of crack initiation and propagation till to fracture of Al2O3 seeded P/M Rene 95 Ni-base superalloy. The experimental results show that non-metallic inclusion can induce initiation of cracks. When the inclusion size is larger than a certain critical size, the crack can propagate to be the main crack inducing the specimen to fracture. Consequently, the yield strength, tensile strength and life of LCF of the specimen are all decreased.
YANG Zu-pei, LIU Shao-heng, GAO Feng, TIAN Chang-sheng. The Effect of PT Content on the Electrostriction and Electric Hysteresis of PMN-based Ceramics[J]. Journal of Materials Engineering, 2005, 0(3): 14-17.
The pure perovskite(1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 ceramics were prepared by molten salt synthesis using mixtures of NaCl-KCl salt. The dielectric, electrostrictive properties and electric hysteresis have been investigated. The results indicate that the Cure Temperature Tm, maximum dielectric constant εmax and electrostriction strain Smax and the hysteresis increases as well as the diffuse phase transition δ decreases with PT content increased.
WANG Hong-wei, WEI Zun-jie, ZHU Zhao-jun, ZENG Song-yan. Site Effectiveness of Thin-wall Aluminum-silicon Alloy Castings in Differential Pressure Casting Process[J]. Journal of Materials Engineering, 2005, 0(3): 18-21,59.
Different site microstructure and mechanical properties of aluminum-silicon alloy in differential pressure casting process were investigated. The gate system was adopted vertical slitting gate system. In the investigation at the inner-gate site of the castings the grain is finer, the density is higher and the mechanical properties is best than that of at the cooling site of castings no matter with SiO2 sand mould, SiC sand mould or chill. However, the grain size, density and mechanical properties of castings between inner-gate site and cooling site are minimum. The analysis results reveal that solidification pressure has site effectiveness during producing aluminum alloy castings by using vertical slitting gate system with a differential pressure casting process. At the inner-gate site the molten metal has higher temperature and longer solidification time that make solidification pressure has longer performance time during molten metal solidification process. Thus solidification pressure has prominent effect on solidification of molten metal at inner-gate site. At the cooling site of the casting the molten metal has the lowest temperature and the shortest solidification time. The solidification pressure has little effect on the solidification of the molten metal at this site. By contraries, the cooling rate has prominent effect on grain size, density and mechanical properties. The solidification of molten metal between the inner-gate site and the cooling site of casting receives little effect from solidification pressure and cooling rate and give rise to biggest grain size, minimal density and lowest mechanical properties. With the increase of cooling rate, the microstructure and properties of castings at every site are improved.
ZHANG Hai-quan, ZHAO Hai-yan, ZHANG Yan-hua, LI Liu-he, ZHANG Xing-an. Analysis on the Microfissuring Behavior in the Heat-affected Zone of Electron-beam Welded Nickel-based Superalloy[J]. Journal of Materials Engineering, 2005, 0(3): 22-25,64.
The microfissuring behaviors in the heat-affected zone(HAZ) of electron beam(EB) welded nickel-based superalloy GH 4133 have been studied by using analytical scanning electron microscopy(SEM). It is observed that considerable liquation microcracks and some other microffissures called solid-state microcrack initiate in the regions nearby the fusion line and propagate across the grain boundary. The microstructure observation in the microfissures suggests the liquation microcrack results from grain boundary liquation by constitutional liquation of MC carbides and formation of continuous and/or semi-continuous low melting liquid films, however, the occurrence of the solid-state microcracks can be attributed to the effect of ultrafast transit thermal shock introduced by high energy electron beam. Minimal the tendency of microcracks can be obtained by improving the shape of weld pool and enhancing the welding energy input.
CUI Lan, JI Xiao-na, CHEN Xiao-ping, DING Li, XUE Tao, ZHANG Chang-liang. Study of a Heavily Deformation Processed Cu-Fe In Situ Composites[J]. Journal of Materials Engineering, 2005, 0(3): 26-29.
The microstructures and properties of the Cu-1%Fe(mass fraction) alloy processed by using thermo-mechanical processing were studied. The results indicated that the strength and conductivity could be improved by appropriate combination of deformation and heat treatment.
FANG Shao-ming, LIN Zhi-feng, ZHOU Li-ming, GAO Li-jun. Influence of the System of Amine Curing Agent-swelling Agent on the Exfoliation of Clay in Epoxy Resin[J]. Journal of Materials Engineering, 2005, 0(3): 30-32,36.
Based on analyzing the system of amine curing agent-swelling agent, the system of tertiary amine curing agent(BDMA)-Bronsted acid swelling agent has been chosen to prepare epoxy/clay nanocomposite. The XRD analysis of nanocomposite showed that was exfoliated clay gained in epoxy resin. The conclusion has been put forward that if other experimental conditions are right and swelling agent is Bronsted acid or curing agent is tertiary amine, exfoliated epoxy/clay nanocomposite can be gained.
HUANG Da-qing, HA En-hua, HE Shan, DING He-yan. Study on Attenuating and Absorbing of Wideband Radar Surface Waves[J]. Journal of Materials Engineering, 2005, 0(3): 33-36.
Attenuating and absorbing of surface wave on targets is vital for targets' stealth. Characteristics of attenuating and absorbing of super wideband radar surface wave by means of radar absorbing coatings as well as radar absorbing coatings combined with frequency selective surfaces are studied and then reported here. The results show that thinner radar absorbing coatings can strongly attenuate high frequency surface waves ,while alternate using of thin radar absorbing coatings and thin radar absorbing coatings compounded by frequency selective surfaces can strongly attenuate wideband surface wave and it is possible that high performance balanced stealth of super wideband can be reached using the alternate radar absorbing coatings.
CAO Tong-kun, DENG Jian-xin, SUN Jun-long. Study on Self-lubricating Al2O3/TiC/CaF2 Ceramic Composites[J]. Journal of Materials Engineering, 2005, 0(3): 37-39,42.
The Al2O3/TiC/CaF2 self-lubricating ceramic composites were produced by means of hot-pressing. Mechanical properties and microstructure were analyzed. It was found that the Al2O3/TiC with 10%(mass fraction,the same below) CaF2 had the highest hardness, HV1537, and bending strength, 589MPa. Friction and wear properties of the ceramic composites were investigated at room temperature. It was found that the Al2O3/TiC with 10% CaF2 had the lowest friction coefficient, about 0.28, while the Al2O3/TiC with 15% CaF2 had higher friction coefficient, about 0.32. The proper addition of CaF2 decreased friction coefficient of the Al2O3/TiC/CaF2 composite, which showed some self-lubricating property.
GAO Hong-bo, XIE Shou-ming, ZHAO Jie, WANG Lai, HAN Shuang-qi. Microstructural Changes and Residual Life Prediction of 12Cr1MoV Steel[J]. Journal of Materials Engineering, 2005, 0(3): 40-42.
12Cr1MoV steel was widely used in high-temperature components of power plants and boilers. It has been shown that the creep-rupture strength decreased with microstructural degradation. The relationship based on Larson-Miller method can be expressed as:10-3·T·(20+lgtr)=Z-blgσ-cσ where b, c are constant, and Z is a parameter related to degradation of creep-rupture strength. The current work investigated the relationship among microstructure,creep-rupture strength and degradation of property by analyzing creep-rupture strength data. Several 12Cr1MoV steels which had different microstructure were investigated to establish a new analytical model for predicting the residual life of high-temperature component.
TANG Bang-ming, LIANG Zi-qing, CAI Shan, ZHANG Zi-long, YI Xiao-su. Investigation of Separability of Resin Film Used in Advanced Composite Resin Film Infusion Technology[J]. Journal of Materials Engineering, 2005, 0(3): 43-47.
T-peel test is used to characteristic the separation processes of resin film from release paper. Load-displacement behavior of some elementary resin films in T-peel test processes used in RFI technology are investigated at various loading rates and test temperatures. The results show that the load-displacement curves of cohesive failure differ much from that of interface failure. It prefers cohesive failure at high temperature, otherwise it tend to interface failure at high loading rate. It is deduced that the available processes for resin film separated from release paper is limited in the temperature range which appears as interface failure at T-peel test.
CHEN Yan, YANG Shang-lei, XUE Xiao-huai, LOU Song-nian. Vacuum Electron Beam Smelting Technology of the Re-Ti Intermediate Transition Layer[J]. Journal of Materials Engineering, 2005, 0(3): 48-51.
By fully automatic loop-locked controlling equipment of vacuum electron beam smelting, intermediate transition layer without brittle phase Ti5Re24 has been obtained. And the components in the layer transit continuously. From the result of hardness measurement it can be seen that both the hardness solidness at the surface and terminal face of intermediate transition layer is higher than that of the titanium alloy and pure rhenium. In general, the hardness solidness decreases with the increasing of the Me content, and increases with the increasing of the rhenium content. At the same time, with the increasing of the rhenium content, the intermediate transition layer became more brittle and more difficult for processing.
YANG Si-yi, LU Guang-shu. Testing Study on the Properties of Foam Al-alloys of Penetrating Casting Around Granules[J]. Journal of Materials Engineering, 2005, 0(3): 52-54.
Property characteristic of foam Al-alloys of penetrating casting around granules was studied. Mechanical properties, fluid permeability, acoustical properties, heat conductivity and damping capacity were tested by testing methods and testing units that we design. We think the mechanical properties and conductivity of foam Al-alloys are lower than solid material, and foam alloy have excellent permeability, noise elimination and damping capacity, which is the basis that foam Al-alloys are used as functional materials.
LIN Jian, ZHAO Hai-yan, CAI Zhi-peng, LU An-li. Recent Development of Reduction of Residual Stress in Steel by Magnetic Treatment[J]. Journal of Materials Engineering, 2005, 0(3): 55-59.
Magnetic treatment is a novel method to relieve residual stress in steel, which is highly effective and power saving. In addition the method would not bring unexpected material structures. Therefore this method has a potential to be used more widely. The development of the method in recent years was introduced and discussed in details, and an expectation for this method was given.
HUANG Jin-song, LIU Yong, DU Yong, LIU Zu-ming, GUO Sheng, HUANG Bai-yun. Review on Development of Al-based Amorphous Alloy[J]. Journal of Materials Engineering, 2005, 0(3): 60-64.
The formation mechanism of Al-based amorphous alloy was summarized and it has the characteristic of valence electron concentration and the principle of similarity. The Al-based amorphous alloy forms in the peritectic reaction and peritectoid reaction,and its growth velocity is slow. The characteristics of microstructure and phase change for Al-based amorphous alloy was introduced.The properties of Al-based amorphous alloy were summarized. The Al-based amorphous alloy has the high hardness,high elastic modulus and high strenghth,and it is brittle at room temperature. The Al-based amorphous alloy has the fine anti-corrosion ability, anti-wear ability and low friction coefficient. The application of Al-based amorphous alloy was reviewed.
