LI Bin-tai, XING Li-ying, ZHOU Zheng-gang, JIANG Shi-cai, CHEN Xiang-bao. Study on Mechanical Properties of High Performance Envelope Materials[J]. Journal of Materials Engineering, 2010, 0(12): 1-4,13.
The relationship between the weaves and the mechanical properties of several high performance fabrics,including PBO(p-phenylene benzobisoxazole) fabrics,was investigated.Among them the fabrics made from PBO fiber showed better tensile properties.Laminated envelope materials,produced by bonding fabrics together with other function components were tested mechanically.For laminated envelope material,breaking strength is mainly dependent on the fibers making them up and the structural characteristics of the fabric.Besides the fibers being used,tearing strength relates strongly to the linear density of the yarns.Higher linear density of the yarns would be useful to increase the tearing strength.
MENG Jiang-yan, WANG Yun-ying, LIN Cui, LIU Feng. Development of Protective Coating for Chemical-milling of Titanium Alloy[J]. Journal of Materials Engineering, 2010, 0(12): 5-7,34.
Polystyrene and styrene-butadiene-styrene(SBS)block copolymer were utilized as the membrane of the protective coating,thermosplastic phenolics saturation solution was used to control etching ratio,and content of the additive was optimized,and the protective coating for chemical-milling of the titanium were prepared,the chemical-milling solution for the titanium alloy is HF-HNO3 system.The properties of the protective coating were measured and analyzed.The results showed that the protective coating is easy to form film and easy to be peeled,the etching ratio of titanium alloy after soaked in the solution of the chemical-milling was 0.4-0.6,and the roughness of titanium alloy could meet its accuracy chemical-milling requirement after it was chemical-milled.
FENG Ming-jie, WANG En-gang, HE Ji-cheng. Numerical Simulation on Temperature Wave of High Steel Composite Roll Under Periodic Heating Shock During Continuous Hot Slab Rolling[J]. Journal of Materials Engineering, 2010, 0(12): 8-13.
A 2-dimension heat transfer model of high steel composite rolls during continuous hot slab rolling was established,meanwhile the spreading properties of temperature waves under periodic heating shock and the effects of biting temperature or rolling speed of slabs on temperature waves in the rolls were studied by use of rotating reference frame and user-defined functions based on Flunet6.3 software.At the same time,the appropriate depth of working layer of high speed steel composite roll was also discussed.The results indicate that the temperature field in the rolls can be describe by use of a high-frequency temperature wave and low-frequency temperature wave of which periodic is the costing time of work roll rotating one cycle and rolling one slab,respectively.The high-frequency temperature wave has severe thin-liver effect,while the low-frequency temperature wave slowly attenuates with depth and its influence depth is much deeper than that of high-frequency temperature wave.The value of temperature fluctuation increases with biting temperature rising and decreases with rolling speed rising at the same depth,and the influence of rolling parameters on temperature fluctuation of high-frequency temperature wave is much greater than that of low-frequency temperature wave.When the depth of working layer is enough,the impact of low-frequency temperature wave on composite quality of high speed steel composite rolls can be avoided.
LI Xue-lei, ZHU Zeng-wei, ZHU Di. Effect of Abrasion-assisted Electroforming with Free Particles on Surface Quality and Mn Content of Ni-Mn Alloys[J]. Journal of Materials Engineering, 2010, 0(12): 14-18.
The Ni-Mn alloy was electroformed by using the dissociating hard particles to improve the quality of electroformed layer.Morphology,surface roughness,Mn content in the electroformed layer and current efficiency were measured and analyzed.In a comparison with the samples conducted by traditional electroforming method,the abrasion-assisted electroforming way offered bright and smooth surface across the Ni-Mn layer with the obvious improvement that surface roughness decreased to 0.05μm from 0.6μm,the size of crystal grains was considerably fined to less than 150nm from micrometer-scale and the current efficiency was largely raised from 80% to 96%.The results show that the Mn content in the deposited alloy layer can be raised with the increase of cathode rotating speed in a certain range,but decreased out of this range.
SUN Shu-li, ZHANG Min-gang, HE Wen-wu, CHEN Hui-qin, TIAN Xiang-ju. Hot Deformation Mechanism and Microstructure Evolution of 9%Cr Heat Resistant Steel[J]. Journal of Materials Engineering, 2010, 0(12): 19-23.
Hot deformation behavior of 9%Cr heat resistant steel with equiaxed forging microstructure was investigated at 1000-1300℃,strain rates ranged in 0.005-5s-1 and maximum deformation to 50% by means of hot compression tests at isothermal and constant strain rate.The effects of thermal-mechanical deformation parameters on stress-strain curves and microstructure evolution mechanism were analyzed.And hot processing maps of different strains were established.The results indicate that 9%Cr heat resistant steel could acquire better microstructure,property and avoid crack using the new technology,by increasing hot deformation temperature and strain rate,breaking through the traditionally initial forging temperature about 1200℃.
ZHAO Yun-feng, ZHANG Ji-hua, YOU Shao-xiong, ZHAN Mao-sheng. Storage Stability of Vulcanized Acrylonitrile-butadiene/Phenolic Resin/Hindered Phenol AO60 Damping Rubbers[J]. Journal of Materials Engineering, 2010, 0(12): 24-29.
The phenolic resin(PR) and tetrakis(methylene-3-(3-5-ditert2butyl242hydroxy phenyl) propionyloxy) methane(AO60) were added into the acrylonitrile-butadiene rubber(NBR) to prepare the vulcanized NBR/PR/ hindered phenol rubbers.The structures of the vulcanized rubbers were characterized by DSC,FTIR,DMTA and SEM.And their damping and mechanical mechanism were investigated in detail.The results show that the microscopic structures of vulcanized rubber include the networks of intermolecular hydrogen bonds between NBR and AO60 molecules,the nonbonding complexation of PR in NBR,the molecular aggregation of AO60(AO60 rich phase) and NBR segments incorporate into the AO60 molecular aggregations besides the vulcanized networks of NBR.These complex molecular interactions lead to the increase of internal friction,and thus vulcanized rubber obtain good damping properties.However,with the increasing of the deposited time,the two-peak tanδ-temperature curve changes to three-peak tanδ-temperature curve,the AO60 molecules aggregate and crystalline in the inner structures of rubbers,and gather together to form bigger AO60 congeries,which affects the stability of damping properties of the vulcanized rubber.
LÜ Chen-jing, TIAN Xiu-shu, HAN Yu-fang. Mechanism of Synthesizing Al2O3/Ti-Al Composites with Al2O3 Whiskers by In-situ Process[J]. Journal of Materials Engineering, 2010, 0(12): 30-34.
In-situ composite of Al2O3/Ti-Al with Al2O3 whiskers were prepared by partial oxidation of oxygen to Ti powder and Al power,crystal phase composition and elemental composition were analyzed by XRD,EDAX and NORAN.The results indicate that,the process of the reaction is as follows: surface of Ti and Al being oxidized→melting of Al→form of TiAl3→form of other Ti-Al intermellics and deoxidized of TiO2 by Al;the crystal composition is determined by aluminum content,when the content is enough,TiAl3,Al and Al2O3 will be gain,on the contrary,Ti2Al,TiAl,Ti3Al and Al2O3 will be gain;Al2O3 whiskers are synthesized via VLS process,the quantity of Al2O3 whiskers increase with the Al content,the whisker’s diameter is improved with increasing of sintering temperature.
WANG Hui-peng, DONG Shi-yun, DONG Li-hong, XU Bin-shi. Study on Influence Factors of Magnetic Memory Signals Under Different Stress Concentration Factors[J]. Journal of Materials Engineering, 2010, 0(12): 35-38.
The tension-tension fatigue tests were carried out with specimens under different stress concentration factors made of 45CrNiMoVA steel.The magnetic memory signals of different scan lines under different loads and fatigue cycles were measured by magnetic memory instruments.The results showed that the signal curves rotated clockwise as the increase of load and cycle,and load played a much more important role in the rotation.The magnetic memory signals showed different characteristics on the different measured lines.The peak-to-peak value of abnormal peaks increased dramatically in a certain range after fatigue crack initiation.
YANG Zheng-wei, ZHANG Wei, TIAN Gan, SONG Yuan-jia, JIN Guo-feng. Debond in Small Curvature Adhesion Structure Detected by Thermal Wave Nondestructive Testing[J]. Journal of Materials Engineering, 2010, 0(12): 39-43.
Based on thermal wave nondestructive technique,the small curvature adhesion structure with debond defects between steel shell and rubber insulation layer was investigated.For the problem of non-uniformity,high noise and low display contrast of the infrared images obtained by the infrared thermal camera,self-adaptive filtering and watershed segmentation algorithms were used to enhance the image quality and segment the defect from the background.Finally,the defect location,size and depth were estimated quantitatively.The results show that thermal wave technique has a high inspection speed(several seconds),locates defect exactly and has intuitionistic inspection results.It is also very applicable to small curvature adhesion structure.Debond with diameter of 15mm at the depth of 4mm is easy to be detected,which could satisfy the inspection requirement for solid rocket motor(SRM).The bigger of the debond area,the easier to be detected and also the less of the error for estimating defect size.
YANG You. Experimental Investigation on High Cycle Fatigue Behaviors of MB8 Magnesium Alloy[J]. Journal of Materials Engineering, 2010, 0(12): 44-46.
The high cycle fatigue behavior of MB8 magnesium alloy at room temperature was investigated by fatigue test using up-and-down method.The fatigue strength of MB8 magnesium alloy was 90.2MPa under stress ratio R=0.1 and cycles N=107 conditions.The fatigue strength was about 34% of its tensile strength.The fatigue cracks initiated at surface of the samples.The fatigue crack propagation regions of MB8 alloy were composed of some facets,and without obvious fatigue striations.The fatigue fracture surface of specimens revealed the fracture characteristics of dimple.
LIU Jin-long, SHI Duo-qi, YANG Xiao-guang, BAO Yu, WANG Jing-ke. Study on Influence of Strain Ratio on Low Cycle Fatigue Behavior of Directionally Solidified Superalloy DZ125[J]. Journal of Materials Engineering, 2010, 0(12): 47-50,60.
The low cycle fatigue(LCF) behaviors of a directionally solidified nickel-based superalloy DZ125 at 850℃ and 980℃ were investigated.The effect of strain ratio(R=-1,0) on the stress-strain hysteresis loop,cyclic mean stress evolution and fatigue lives was analyzed.The results indicated that the scatter of fatigue life for R=-1 and R=0 was small enough to be neglected at 850℃ and 980℃.The fracture cross section was observed using scan electronic microscopic(SEM) to analyze the crack initiation mechanism.
SI Jia-yong, GAO Fan, ZHANG Ji. Effect of Direction on Flow Behavior of TiAl Alloy in Secondary Hot Deformation[J]. Journal of Materials Engineering, 2010, 0(12): 51-54,65.
The flow behavior of already forged Ti-46.2Al-2.5V-1.0Cr-0.3Ni alloy by the isothermal compression experiments was investigated.The direction of secondary hot deformation was taken to be vertical or parallel to the former forging axis(reversed or unreversed deformation).Specimens have three kinds of starting microstructures,as-forged,relief annealed and duplex.The results show that reversed deformation can accelerate the decline of work hardening rate.And compared with other two microstructures,the duplex microstructure has the lowest softening degree in reversed or unreversed secondary hot deformation.According to the results of microstructure observation,the reversed secondary hot deformation can be favorable to the breakdown and dynamic recrystallization of remanent lamellar structure.
ZHENG Yun-rong, CAI Yu-lin. Structural Transformation of Al-Cr Coating on K403 Nickel-base Alloy and Effect of Orientation and Stress[J]. Journal of Materials Engineering, 2010, 0(12): 55-60.
The microstructural transformations of Al-Cr coating on as-cast nickel base superalloy K403 with equiaxed grain or single crystal structure at high temperature for long term thermal exposure were analyzed by physical metallurgy methods.The effect of stress on degradation of coating was also investigated.The results indicate that the Al-Cr coating exhibits superior stability and can bear long term thermal exposure for 5000h bellow 900℃.The crystal orientation does not influence the formation or transformation of coating obviously,but can significantly vary the arrangement of σ phase.Stress promotes the thickness of coating,also the precipitation and coarsening of phases.Above 1050℃,the transformation of β→γ in coating completes for 1000h.Moreover,precipitates including σ phase and M6C carbide are coarsened very quickly and these cause the serious damage of coating structure.
XU Qiao-yu, HE Wei-jiao. Wear Resistance of Amorphous Ni-P-ZrO2 Composite Coating[J]. Journal of Materials Engineering, 2010, 0(12): 61-65.
The Ni-P-ZrO2 composite coatings were prepared by electroplating.The influence of nano-ZrO2 particles and different temperatures of heat treatment on wear resistance of both Ni-P coating and Ni-P-ZrO2 composite coating were investigated.The results show that nano-ZrO2 particles can improve the wear resistance of amorphous coating and without changing its amorphous structure;the wear resistance of as-plated Ni-P coating is affected by both adhesive wear and microploughing wear mechanism,under this situation its wear resistance is poor;the addition of nano-ZrO2 particles in coating can relieve the wear resistance of composite coating’s adhesive wear and microploughing action.After heat treatment at 350℃ for 1h the composite coating has the best wear resistance.Furthermore,the wear mechanism changes to adhesive wear and micro-spalling wear mechanism.
MA Guo-zheng, XU Bin-shi, WANG Hai-dou, LIU Yong, YE Zhu-yu. Tribological Properties of Electric Brush Plating In/Ni Combination Coating in Vacuum[J]. Journal of Materials Engineering, 2010, 0(12): 66-71.
An In/Ni combination coating with the thickness of about 10μm was prepared by electro-brush plating on the surface of medium carbon steel.The mechanisms of anti-friction and micro-damage process of the combination coating were studied.The influences of sliding velocity and normal load on the tribological properties of the coating in high vacuum were investigated.The results showed that the combination coating had good friction-reduction and adhesive wear resistance properties;the friction coefficient decreased with the increased of sliding velocity and normal load;the wear rate increased with the increased of load,but didn’t respond to sliding velocity remarkably.Abrasive wear and adhesive wear were the predominant wear mechanisms of the coating in high vacuum.
DING Xin-geng, CHEN Yuan, WU Chun-chun, YANG Hui. Hydrolyze-polymerization Process and Anti-corrosion Property of KH570-SiO2 Composite Sol[J]. Journal of Materials Engineering, 2010, 0(12): 72-76.
Using sol-gel method,γ-methacryloxypropyltrimethoxysilane(KH570)-modified tetraethylorthosilicate(TEOS) as precursor,the poly-organic-inorganic anti-corrosion coating on steel plate was prepared.The structure of the coating was studied by Fourier transform infrared spectroscopy(FTIR) and scanning electronic microscopy(SEM).The anti-corrosion property of the coating was measured by salt-spray test and electrochemical impedance spectroscopy assay.The effect of water addition was investigated.The results showed that as the water addition(R) increased from 1 to 5,the anti-corrosion performance firstly enhanced and then declined.When R=3,the coating was compact in structure,and had the optimal anti-corrosion property.The FTIR study revealed that the structure of KH570 had no significant change after heat treatment at 180℃.
WANG Hai-ren, ZHENG En-xiu, GUO Xing-peng, SHI Xing-yang, LI Wen-wei. Research on Computer Monitoring System Applying to Stainless Steel Chemical Coloring[J]. Journal of Materials Engineering, 2010, 0(12): 77-81.
Based on the potential control theory and the practical experience stainless steel surface coloring computer monitoring system was developed.The control theory,the determining of the sensor,its software design features and the innovations of the system were introduced in detail.The results show that the system can effectively control the coloring of stainless steel.Not only does it overcome the problems of poor reproducibility,but also it makes the research of coloring influences such as temperature,additives and the pretreatment more convenient and reliable.
Qu Chun-yan, LI Lin, WANG De-zhi. Study on Surface Treatment of Titanium Alloy for Adhesive Bonding[J]. Journal of Materials Engineering, 2010, 0(12): 82-85.
The surface treatment of titanium alloy was one of important factors that affect the durability of titanium alloy adhesive joints.The various methods of surface treatment and surface analysis techniques were introduced.The contribution of these methods for bonding durability was also evaluated.Based on hot/wet durability as examining point show that electrochemical treatments are superior to chemical treatments and mechanical treatments are inferior to the chemical treatments.In addition,physical treatments in the research stage such as plasma sprays and laser treatment etc.are promising in industrial fields because of their acceptable durability and less pollution characteristics.
SHEN Ming-xue, PENG Jin-fang, ZHENG Jian-feng, SONG Chuan, MO Ji-liang, ZHU Min-hao. Study and Development of Fretting Fatigue[J]. Journal of Materials Engineering, 2010, 0(12): 86-91.
The concepts and experimental rigs of fretting fatigue were introduced.The domestic and overseas current situation of fretting fatigue studies was reviewed in detail.The influential factors(contact pressure,slip amplitude,experiment frequency,friction force,environment and material properties) of fretting fatigue as well as damage mechanisms,life assessment methods and protective measures were analyzed and discussed comprehensively.Some prospects in relation to further researches were also presented.
XU Zhi-wei, GUO Qi-wei, WANG Xiao-sheng, WU Ning, WU Xiao-qing, CHEN Li. Effect of Electron-beam Irradiation on Structure and Properties of CNTs[J]. Journal of Materials Engineering, 2010, 0(12): 92-97.
Research advances on electron-beam irradiation of carbon nanotubes(CNTs) were reviewed,and the structural defects,diameter,mechanical property,electrical property and field emission performance of irradiated CNTs gain much attention.The cutting and welding of CNTs via electron-beam irradiation were evaluated and the effect of temperature and incident electron energy on the irradiation results was discussed.It is expected that the electron-beam irradiation of CNTs may be research focus in the future.
