CHEN Xiu-hua, HU Pei, WANG Hai. Three-parameter Generalized Failure Criteria Based on Tension, Compression and Shear Uniaxial Strength[J]. Journal of Materials Engineering, 2009, 0(10): 1-6.
Based on the spherical tensor invariant and the deviator tensor invariant,a three-parameter generalized failure criteria was obtained based on the tension,compression and shear uniaxial strength value.This generalized failure criteria satisfy the pure tension,pure compression and pure shear test strictly.The criteria incorporate both the hydrostatic tensor influence and the octahedral shear tensor.Then,some typical stress states are discussed and compared the strength envelope among the 3-P generalized failure criteria to the common criteria.Also three types ROHACELL PMI foam material strength test are presented to support the criteria,and confirmed that this criteria is more suitable for describing the material failure envelope of ROHACELL PMI foam material.
ZOU Jin-wen, LIU Dong, LIU Bai-cheng, SHEN Hou-fa. Simulation of Wind Chill Process for Turbine Disk[J]. Journal of Materials Engineering, 2009, 0(10): 7-10.
The wind chill process for FGH96 turbine disk was simulated and studied by using the commercial CFD software.The distribution of parameters such as temperature and cooling rate were analyzed quantitatively.The results showed that the temperature distribution in radial and circumferential directions of disk was more homogeneous in the case using single fan than that in the case using three fans.The results of wind field showed that the cooling rate when using single fan was higher.
YUAN Song-dong, CAO Xiao-yan, WANG Xiao-bo, SHI Biao, WANG Jin-fang. Synthesis of Ag-doping TiO2 Nanobelt and Study on Its Photocatalytic Character[J]. Journal of Materials Engineering, 2009, 0(10): 11-14,19.
Being a sort of 1D nano-photocatalytic,TiO2 nanobelt can overcome the shortcoming of TiO2 nanoparticle,which is hard to be recycled.The photocatalytic activity can be improved by doping noble metal.In the research,Ag-doping TiO2(Ag/TiO2) nanobelts with different Ag content were prepared with cheap titania pigment by hydrothermal method and analyzed by XRD,SEM and EDS.The photocatalytic degradation of methyl orange over Ag/TiO2 nanobelt was studied in aqueous suspension under UV light.The effect of Ag content,calcination temperature and the catalyzer’s content were investigated.The results showed that the degradation rate of methyl orange could reach 98.51% when the content of Ag is 0.1%(mass fraction,the same below),calcination temperature is 700℃,the amount of catalyst is 0.05g and exposed at room temperature for 3h under 15W UV light illumination.The degradation rate was increased by 22% compared with original nanobelt.
CHEN Gao-sheng, ZHANG Lian-hong, LI Fu-ping, QIN Hai-ying, LI Man-fu. Finite Element Analysis for the Influence of Spherical Layered Elastomeric Bearing Structure on the Mechanical Behavior[J]. Journal of Materials Engineering, 2009, 0(10): 15-19.
The mechanical behavior of spherical layered elastomeric bearing was simulated by ANSYS software using the finite element method,and the stress distribution in rubber layers was obtained.Effects of structure elements,such as shape of injection hole,thickness of rubber layers and profile of the elastomeric bearing,on the maximum node stresses of rubber layers were also analyzed.Results showed that the maximum node stresses in the first and second rubber layers of the bearing obtained by using the conic injection hole were less than that obtained by using the cylindrical injection hole.The maximum node stresses in all rubber layers could be reduced by proper design of the thickness of rubber layers.The dramatic changes of node stresses between rubber layers were decreased in the bearing with an arc profile,which could improve the life of the elastomeric bearing.
LÜ Xiang-hong, ZHAO Guo-xian, ZHANG Jian-bing, HAN Yong, XU Wen-yan. Corrosion Behavior of Low Cr Steel at the Simulated H2S/CO2 Environments[J]. Journal of Materials Engineering, 2009, 0(10): 20-25,31.
H2S/CO2 corrosion behavior of low Cr casing and tubing steel at the simulated environments of Tarim oilfield was studied with mass loss and electrochemical impedance spectroscopy(EIS) and polarization curves.The results show that low Cr steel has the superior CO2 uniform and local corrosion resistance because Cr-rich in corrosion scale which improve the protection of corrosion scale.At the simulated CO2/H2S environment,H2S electrochemical corrosion dominates the corrosion course,and the uniform corrosion rate of low Cr steel is much less than that in CO2 environment.The passivation zone of low Cr steel appears obviously on anodic polarization curve in H2S corrosion environment,and the fitted EIS showed that the polarization resistance of H2S corrosion is much larger than that of CO2 corrosion.
GONG Hai-fei, SHAO Tian-min. Influence of Toughness on Tribological Performance of TiN/Ti Multilayer Coatings[J]. Journal of Materials Engineering, 2009, 0(10): 26-31.
Influence of toughness on tribological performance of TiN/Ti multilayer coatings was investigated.Filtered cathode vacuum arc(FCVA) deposition method was applied to prepare the TiN/Ti multilayer coatings with different Ti sublayer thickness.Transmission electron microscope(TEM) was used to observe the laminate structure and individual layer thickness of the TiN/Ti multilayer coatings.Indentation test and wear experiment were carried out on Rockwell-C hardmeter and universal micro materials tester(UMT),respectively.The experimental results showed that the introduction of Ti sublayer in TiN/Ti multilayers remarkably enhanced toughness of the multilayers.Under relatively large load,wear resistance of the TiN/Ti multilayer coatings was evidently improved comparing to TiN monolayer.Finally,according to the experimental results,the influence of toughness on wear resistance of the TiN/Ti multilayer coatings was discussed.
HUA Xing-yan, WANG Yuan-sheng, ZHAO Pei-zhong, ZHU Jin-hua. Properties and Structure of Semirigid PU/ER Interpenetrating Polymer Networks Foams[J]. Journal of Materials Engineering, 2009, 0(10): 32-35,40.
A series of semirigid interpenetrating polymer networks(IPN) foams,based on polyurethane(PU) and epoxy resin(ER),were prepared by a simultaneous polymerization technique.The changes of the chemical structure,dynamic mechanical properties,and morphology of the semirigid IPN foams were investigated by Fourier transform infrared(FTIR) spectroscopy,dynamic mechanical thermal analysis(DMA),and scanning electron microscopy(SEM).The FTIR showed that there existed some chemical bonds between PU and ER component in the IPN foams.All of the semirigid IPN foams over a wide range of component ratios exhibited single and broad glass transition peaks that shifted to higher temperature as the epoxy resin content increased.The cell shape of all the IPN foams are just about round and uniform.All of the IPN foams showed good flexibility and deformation resilience when deformed repeatedly under cyclic compression.
FENG Tong-bo, ZHAO Yan, LUO Yun-feng. Hygrothermal Property of CCF/BMI Composites with Different Sizing on the Carbon Fiber[J]. Journal of Materials Engineering, 2009, 0(10): 36-40.
The hygrothermal property of CCF/BMI composites with different sizing on the carbon fiber was analyzed.The water absorption,ILSS,bending property,failure mode and SEM appearance of the break were changed after the composites were soaked in water at 71℃ for seven days.From these changes,it can be found that the sizing have a remakable impact on the hygrothermal property of these composites.Compared with CCF/BMI,the properties of T300/BMI are much better.The different properties between them may be made by the different sizing which they are used.
JI Wei, FAN Ya-fu, CHEN Jie, WANG Jun. Effect of Temperature on the Dynamic Tensile Behavior and Fracture Mechanism of Mg-10Gd-2Y-0.5Zr Alloy[J]. Journal of Materials Engineering, 2009, 0(10): 41-44.
The dynamic tensile behaviors of two kinds of Mg-10Gd-2Y-0.5Zr alloys were investigated using a high-temperature split Hopkinson Bar at 423-798K and strain-rate of about 103s-1.Microstructures adjacent to the fracture and morphologies were examined by optical microscope and scanning electron microscope.The results indicate that the fracture mechanism varies from the mixed mechanisms of shallow-dimples and quasi-cleavage fracture(T≤673K) to intergranular rupture(T≥735K) with increasing temperature.When T<673K,the main deformation mechanism of the tensile samples are basal slip.In addition to basal slip,pyramidal slip and prismatic slip will be gradually activated with continually increasing temperature,which account for the maximum elongation of the samples tensioned at 735K.
WU Yun-xin, LIAO Kai. Research of Transverse Stress Reduction in Prestretching of Aluminum Alloy Thick Plate[J]. Journal of Materials Engineering, 2009, 0(10): 45-48.
The distribution of longitudinal(x) and transverse(y) stress along thickness is given by the simulation for pre-stretch processing of aluminum alloy thick-plate using non-liner software MSC.Marc.By simulation and experiment,the phenomena of transverse-stress decrease in stretch are expatiated.The evolvement mechanism of transverse stress is discussed by comparing decrease between longitudinal and transverse stress.The conclusion is that the high-intensity stress sets material in a state of high elastic potential energy,so the outside force makes for breaking down the transverse balance of grain,and changing original balance state of grain’s stress,and then achives the decrease of transverse stress.
LI Ying, LI Chun-guang, HE Yu-huai, JIANG Tao. Failure Analysis of ZM6 Engine Box[J]. Journal of Materials Engineering, 2009, 0(10): 49-52.
A crack was founded in an engine box of an aeroplane during fatigue test by fluorescence penetrate testing.According to the results of macroscopical testing,fractography analysis,chemical analysis,hardness testing and metallographic analysis,it is concluded that the fracture model is low cycle fatigue,Nd segregation of the surface results in the fatigue fracture of the engine box and low material toughness promots the extending of the crack.Based on the analysis results,some measures are brought forward to avoiding the failure of the engine box.
LIANG Ji-zhao, WU Cheng-bao. Study on Relationship Between Impact Strength and Fracture Surface Fractal Dimension of PP/Nano-CaCO3 Composites[J]. Journal of Materials Engineering, 2009, 0(10): 53-56.
The particle surface of nanometer calcium carbonate(Nano-CaCO3) was treated respectively by fatty acid and titanate coupling agent,and PP/Nano-CaCO3 composites were prepared by means of melt blending.The V-notched impact strength of the nano-composite was measured at room temperature.The V-notched impact fracture surface fractal dimensions of PP/Nano-CaCO3 composite were measured by means of projective-covering meathod,and the relationship between fracture surface fractal dimension and impact strength of the composite was investigated.The results show that the fracture surface fractal dimension ranges from 2.3673 to 2.4120,all of the correlation coefficients is higher than 0.95,the strong correlation indicates that impact fracture surface of PP/Nano-CaCO3 composites is evidently fractal,and the relationship between impact strength and fracture surface fractal dimension of the composites obeys roughly exponential function.
SUN Zhi-hua, ZHANG Ni, CAI Jian-ping, LIU Ming, LU Feng, TAO Chun-hu. Study on Accelerated Aging Test of Containing Fluorine Polyurethane Topcoat Applied in Aircraft[J]. Journal of Materials Engineering, 2009, 0(10): 57-60.
The electrochemical impedance varieties of containing fluorine polyurethane topcoat in aircraft during accelerated aging test were studied by means of electrochemical impedance spectroscopy(EIS),and the corrosive failure behavior of the coatings was also investigated.It has been found that the topcoat acts as a pure capacitance before the aging test and can insolate the corrosive media.With the aging time,there is little change of brightness loss and color difference.After 1680h of exposure to the test,the EIS of the topcoat also shows a pure capacitance,and the capacitance calculated according to the equivalent circuit is also very small.It indicates that the topcoat can provide significant protection to aluminum alloy substrate.Comparing with the result of zinc yellow polypropylene primer coated aluminum alloy without the topcoat,the topcoat can improve the anti-aging property greatly.
CHEN Ji-ping, KANG Yong-lin, HAO Ying-min, LIU Guang-ming, XIONG Ai-ming. Experimental Study on Ti Bearing Ultra-low Carbon Bake Hardening Steel Sheet Hot-rolled in Ferrite Region[J]. Journal of Materials Engineering, 2009, 0(10): 61-66.
Hot rolling in the conventional austenite region and in the ferrite region with lubrication,cold rolling and continuous annealing of Ti bearing ultra-low carbon bake hardening steels were experimentally studied.The results showed that the deep drawability could be improved while the yield strength and bake hardenability could be slightly lowered with similar elongation rate for the ultra-low carbon bake hardening steel sheet hot-rolled in the ferrite region with lubrication.It has been shown from the results of the 〈111〉//ND fiber textures of the steel sheet hot-rolled in the ferrite region are a little bit stronger than those of the steel sheet hot-rolled in the austenite region.The orientations among neighboring grains are mainly high angle grain boundaries under both conditions.
ZHANG Bao-yan, ZHOU Zheng-gang, ZHUANG Wen-bo. Influence of Pressure on the Microstructure and Mechanical Properties of 5428VB/T700 Composite[J]. Journal of Materials Engineering, 2009, 0(10): 67-72.
5428VB/T700 is a kind of vacuum bag curable prepreg.In order to improve its popularity,autoclave technique was used to manufacture 5428VB/T700 composite laminates.Influence of pressure magnitude,pressure applied time point on the basic mechanical properties of 5428VB/T700 composite had been investigated here,ultrasonic scanning,microstructure analysis techniques were used to inspect the quality of prepared 5428VB/T700 composite laminates,and the properties of vacuum bag only cured 5428VB/T700 laminates were compared to those of autoclave cured 5428VB/T700 laminates.Results indicated that the short beam shear strength of 5428VB/T700 composite decreased when 0.3-0.6MPa pressure was applied before 130℃/1h compared to those of vacuum bag cured system,but increased with the increase of applied pressure magnitude.The properties and qualities of 5428VB/T700 composite were improved significantly when 0.3-0.6MPa pressure was applied at 130℃/1.5-2.0h,and when the applied pressure was no less than 0.6MPa,the properties and qualities of 5428VB/T700 composite were better than those of vacuum bag only cured 5428VB/T700 laminates.Process of bubbles removed and the formation of voids in composite laminate were discussed.
SUN Zhi-qiang, ZHOU Wen-long, CHEN Guo-qing, HUANG Xia, ZENG Yuan-song. Effect of Age-forming on Microstructures and Properties of 2324 Al Alloy[J]. Journal of Materials Engineering, 2009, 0(10): 73-76,80.
The effect of age-forming on the mechanical properties of 2324 Al alloy was investigated.The microstructure evolution during age-forming was observed with TEM.The "stress orientation effect" of age-forming and its effect on the mechanical properties were studied.The characteristics and the reason of the "stress orientation effect" were analyzed.The results demonstrate that due to the difference of the diffusion coefficients between in the parallel stress direction and vertical stress direction,the precipitates grow preferentially parallel to(11
1) during age-forming while grow uniformly along {201}under stress free ageing,which is the typical "stress orientation effect".The preferential orientation is mainly decided by the direction of the external stress.
WANG Jia-ling, CHEN Zhuo, LI Yu-tian, XIE Ji-jiang. A Study of Bright Heat Treatment for 316L Stainless Steel Coronary Stent[J]. Journal of Materials Engineering, 2009, 0(10): 77-80.
For carrying out the bright heat treatment of the 316L stainless steel coronary stent,a set of high vacuum heat treatment facilities was established.Optimized high vacauum heat treatment process and determined the processing parameters that are dynamic vacuum 3×10-3-5×10-3Pa,argon shield,velocity of flow 10 mL/min,heat treatment temperature 1020-1040℃,heating voltage 150V,heating current 15A,holding time 30s.Discuss the influences contribution to coronary structure property affected by heating temperature and holding time.In the presence of subsidiary gas quick cooling stainless and metallic network,stainless steel avoided getting into sensitization and had been brighten heat treatment.
WANG Bao-shun, DONG Jian-xin, ZHANG Mai-cang, ZHENG Lei. Computational Modeling of the Solidification During Vacuum Consumable Arc Remelting Process[J]. Journal of Materials Engineering, 2009, 0(10): 81-84,90.
The ingot quality of vacuum arc remelting process is depending on the operational parameters.The effect of operational parameters on the solidification during vacuum arc remelting process can be appraised effectively by computational modeling.The computational simulation on the profile of molten pool,fluid motion,temperature distribution within the molten pool and the development of grain structure is introduced in detail in this paper.The simulation results were good agreement with experimental results.
ZHANG Ding-fei, DAI Qing-wei, HU Yao-bo, LAN Wei, FANG Lin. Progress in the Research on Rolling Formation of Magnesium Alloy Sheet[J]. Journal of Materials Engineering, 2009, 0(10): 85-90.
Magnesium alloy sheet plays an important role in the wrought magnesium alloy.However,the processes of rolling formation are unsatisfactory.The characteristics and process of rolling formation of magnesium alloy sheet are analyzed.The effects of different rolling ways,like asynchronous,equal channel angular cross and accumulative rolling,on microstructure and properties are also discussed.And adjusting the rolling process and selecting rolling ways to enhance magnesium alloy rolled formability are mainly demonstrated.Finally the problems,together with the future development of magnesium alloy sheet rolling process,are pointed out.
