XIAO Zhi-chao, JIN Zhi-hao, SHAO Hai-cheng, SU Jun-ming, PENG Zhi-gang, LI Yong-jun. Performance and Test Research of Fluorine-preparing C/C Composites Electrolysis Plank[J]. Journal of Materials Engineering, 2008, 0(1): 1-5.
The C/C composites electrolysis plank that applied to preparing fluorine we produced by carbon fiber perform,pitch infuse and carbonization,resin infuse and carbonization and high temperature treatment processing.Then it was analyzed by mechanics performance,electrical resistivity,thermal performance.At the same time,the C/C composites electrolysis plank was tested in electrobath.The results showed that C/C composites electrolysis plank had high mechanics performance,having perfect tensile strength,compressive strength,flexural strength and shear strength,having excellent anti-corruption,thermal performance and electrical resistivity.It extended life of electrolysis plank and reduced replacing in electrobath.The microstructure was analyzed by SEM.The experiment showed that fracture part was fragile fracture.
ZHAO Long-zhi, HE Xiang-ming, ZHAO Ming-juan, CAO Xiao-ming, ZHANG Jin-song. Thermal Properties of Aluminum Matrix Composites Hybrid Reinforced by SiC Foam and SiC Particles[J]. Journal of Materials Engineering, 2008, 0(1): 6-10.
New model SiC preform made up of SiC foam and SiC particle,SiC foam/particle/Al hybrid composites(VSiC=53%,56%,59.9%)for electronic packaging substrate were fabricated by squeeze casting technology.The thermal conductivity of SiC foam/SiCp/Al hybrid composites on the room temperature was higher than 130 W/(m·℃)because of the special double interpenetrating structure of composites.With increase of the temperature,the specific heat capacity of composites was increased,the thermal diffusivity and the thermal conductivity was decreased.But with the content of SiC reinforcement in the composites,the specific heat capacity was linearly decreased,the thermal diffusivity and the thermal conductivity of composites was fell nonlinearly because of the effect of the thermal barrier at the interface of composites.
MA Cheng-yong, CHENG Hai-feng, TANG Geng-ping, CHU Zeng-yong, XIE Wei. Research on Absorbing Properties of Triple-layer Radar Absorbing Coatings[J]. Journal of Materials Engineering, 2008, 0(1): 11-13.
A kind of thin triple-layer radar absorbing coatings were prepared according to resistance matching principal.And the radar absorbing properties of the coatings were studied.The results showed that the design of multi-layer structure played an important role in improving the absorbing properties of the coatings.The coating with a thickness of 1.20mm and area density of 2.80kg/m2 had a bandwidth of about 6.0GHz under-10dB in 8-18 GHz.
LIANG Xing-quan, LI Ke-wen, LU Fa-yan, ZHENG An-xiong, SONG Jiang-xuan. Study on Properties of Photo-oxidation Degradation of Polyethylene Films in Existence of PEG400[J]. Journal of Materials Engineering, 2008, 0(1): 14-17.
With the analyses of the intrinsic viscosity,the content of gel and carboxyl,and fourier transform infrared spectroscopy,the photo-oxidation degradation process of five polyethylene films containing 8%,5%,1%,0.1%,0%(mass fraction)PEG400 were analyzed respectively in the artificial accelerated climate.The morphologies of polyethylene films containing 1% PEG400 before and after degradation were studied with the Scanning Electron Microscopy(SEM).The results showed that the photo-oxidation reactions process of the polyethylene in films were accelerated by the PEG400,it made the macromolecules of polyethylene chain cross linking or rupture and produced the carbonyl and carboxyl in the molecule chains.With the content of PEG400 at 1%,the polyethylene film had the best degradation effect,the intrinsic viscosity of its polyethylene was decreased from 67.6 Pa·s to 34.9 Pa·s after irradiation 60 days at the experiment condition,the content of gel and carboxyl were 5.84% and 1.29% respectively.
LIANG Ji-zhao, WU Cheng-bao. Fractal Model of Tensile Fracture for Grain Filled Polymer Composites[J]. Journal of Materials Engineering, 2008, 0(1): 18-20.
A tensile facture fractal model of grain filled polymer composites on the base of the fractal theory was established,and an equitation of the tensile fracture fractal dimension was proposed.The tensile fracture fractal dimensions of grain filled polymer composites at volume fraction of the grains from 2% to 30% were calculated and the calculations were compared respectively with measuring values of CaCO3/ABS and TiO2/ABS composites reported in references.The results showed that the theoretic values and the measuring values were roughly close to each other.
TIAN Yong, HE Li-ping, WANG Lu-lin, QU Wei-ping. Study of Mechanical Properties of Ramie Fiber Reinforced Polypropylene Compounds for Automobile Industry[J]. Journal of Materials Engineering, 2008, 0(1): 21-24,33.
The ramie fiber of different length,different content and different dispose methods to reinforce polypropylene were used,and the tensile stress-strain curve,the flexural stress-deflection curve,the compressive stress-deflection curve,the elongation rate and the photos of the rupture interface were analysed,and the mechanical properties(tensile,flexural,compression and impulsion)were studied,and the best manufacture technics of the composites were found.
CHEN Bo, XIONG Hua-ping, MAO Wei, LI Xiao-hong. Wettability of Several High-temperature Brazing Fillers on C/C Composites[J]. Journal of Materials Engineering, 2008, 0(1): 25-29,37.
The wettability of ten kinds of brazing fillers on C/C composite was studied with the sessile drop method.The results showed that the wettability of the brazing fillers on C/C composites was improved with the increase of the content of active elements Ti,Cr or V.In the Co-Ti and Ni-Ti brazing fillers system,the form of the element Ti had an effect on the wettability.When the element Ti existed with solid solution,it tended to react with C/C composite to improve the wettability.The elements Ti and C reacted and formed TiC compound.The active elements Cr,V distributed at the interface between C/C composite and PdNi-Cr-V-Si-B brazing filler and formed Cr23C6 phase and V2C phase respectively.When the elements Cr,V were added concurrently in the brazing filler,the former diffused to the reaction layer more strongly than the latter.
JIA Pan-jiang, TANG Hui, CHEN Bang-feng. Effect of Casting Methods on Mechanical Properties and Fracture Surfaces of ZL210A Casting Aluminum Alloy[J]. Journal of Materials Engineering, 2008, 0(1): 30-33.
The effect of different casting methods of sand mold and metal mold on the mechanical properties and fracture surfaces of ZL210A casting aluminum alloy of casting,solid-solution and aging was investigated.The results showed that the casting method of metal mold had properties advantage over that of the sand mold,the σb,σ0.2 and δ5 of metal mold were better than that of sand mold casting for mechanical properties of ZL210A Al alloy.The fracture modes of the ZL210A test sample were ductile transgranular,and there were many large and deep dimples at the coarse intermetallic phases.The fracture dimples of metal mold solid-solution samples were the most obvious.
YAN Chun-yan, LI Wu-shen, DI Xin-jie, XUE Zhen-kui, BAI Shi-wu, LIU Fang-ming. Feature Extraction of Metal Magnetic Memory Signals for Welding Cracks Based on Wavelet Analysis[J]. Journal of Materials Engineering, 2008, 0(1): 34-37.
Based on multiscale wavelet analysis and fast Fourier transform,metal magnetic memory signals were processed for welding cracks.A criterion feature to identify the existence of welding cracks was found out.Corresponding threshold value of the feature was established.Field inspection indicated that welding cracks could be accurately identified with the criterion feature.
JIANG Hai-tao, MI Zhen-li, TANG Di, WANG Hai-quan, DAI Yong-juan. In-situ Observation of Microstructure in TWIP Steel During Tensile Deformation[J]. Journal of Materials Engineering, 2008, 0(1): 38-41.
The microstructure of Twinning Induced Plastic(TWIP)steel during tensile deformation was investigated with in-situ SEM observation.The results showed that the grains with twins started to deform and work harden,which lead to other grains formed favorable orientation in order to complete further deformation.This deformation mechanism of twinning induced plastic provided the specimens excellent elongation with no-necking phenomenon.In addition,microcracks generated at inclusions and grain boundaries,and merged to crack at the condition of stress concentration.A large amount of strain marks were observed in the tension specimens of the TWIP steel.The strain marks consist of slip lines and small mechanical twins.Because the kink bands and stepped structures appeared in grains for twinning induced plastic,the folding phenomenon of specimen surface occurred.
ZHAO Bin, XU Bao-xing, YUE Zhu-feng. Prediction of Creep Residual Life of Aluminum Alloy 2A12 by Using Indentation Test Method with Flat Cylindrical Indenters[J]. Journal of Materials Engineering, 2008, 0(1): 42-44.
A method of predicting the residual creep life of aluminum alloy 2A12 by using indentation test method with flat cylindrical indenters was proposed.There were four steps included in the meth-od.First,specimens with different creep damage levels were obtained by the tensile creep testing(by control testing time).Second,the above damage specimens were put to the indentation testing,and then the typical load-displacement curves were yielded.Third,correlation equations were used to get pre-damage values.In the end,the residual creep life can be determined by the relationship between the slope of the initial portion of the unloading curve and the damage values.
WANG Wen-jun, GUO Tao, LI Xiao-gang, SHAO Zi-qiang. Synthesis and Application of Thermoplastic Polyimide Based on BTDA[J]. Journal of Materials Engineering, 2008, 0(1): 45-48,53.
A kind of thermoplastic polyimide(TPI)was synthesized with 3,3',4,4'-benzophenone-tetracarboxylic dianhydride(BTDA)and 4,4'-oxydianiline(ODA)as monomers,the imidization process was a chemical one.The glass transition temperature of TPI was 275℃.TGA temperature at 5% mass loss was 560℃,this indicated that the TPI had good thermooxidative stability.Within the interested content range,TPI had good compatibility with LP-15,a semi-interpenetrating network(IPN)was formed between them.When the TPI content was 20%(mass fraction),the Tgvalue and impact strength were 13.5℃ and 256% higher than those of LP-15 respectively,i.e.The modified resin exhibited simultaneous improvement in both toughness and Tg,which were very difficult to achieve by conventional toughing methods.
YAN Yong-lin, ZHENG Yong, LIU Wen-jun, CHENG Xin, ZHAO Neng-wei. Study on Sintering Process of Ti(C,N)-based Cermets[J]. Journal of Materials Engineering, 2008, 0(1): 49-53.
Ti(C,N)-based cermets were produced by vacuum sintering.The effect of sintering temperature and holding time on the microstructure and mechanical properties of Ti(C,N)-based cermets was studied,and the fracture morphology was investigated by scanning electron microscope.The results show that,with the increasing of the sintering temperature,the microstructure of cermets became uniformity,and the ceramic grains got rounded,and the rim phase structure was completeness gradually.When the sintering temperature was too high or the holding time was too long,the rim phase was modified thicken,and the growing phenomenon of grains was abvious,the properties was decreased.The cermets sintered at 1440℃ for 60min showed the best mechanical properties.Their transverse rupture strength reached 1914.2MPa,and the hardness reached 90.1.
ZHANG Bin, XU Bin-shi, DONG Shi-yun, WU Bin. Tribological Properties at Elevated Temperature of Auto Brush Electroplating n-SiC/Ni Composite Coatings[J]. Journal of Materials Engineering, 2008, 0(1): 54-57.
Nanoparticle reinforced nickel matrix composite coatings,n-SiC/Ni,were prepared by manual brush electroplating and auto brush electroplating technology respectively.Microstructure and friction wear properties of the two kinds of coatings were investigated by comparison.Comparing with the manual coating,the auto coating had smoother surface,denser structure and higher hardness.Results of the friction wear testing at elevated temperature showed that the auto composite coating had superior wear resistance to the manual coatings.
CHEN Qing-chun, LIU Xiao-dong, DENG Hui-yu. Study on Hydrothermal Conditions of Preparation of Micro/Nano-structure Leaflike Copper[J]. Journal of Materials Engineering, 2008, 0(1): 58-60.
Via to the XRD and SEM,different morphologies of copper were fabricated under various hydrothermal conditions such as types of polyols used as reductives,amount of polyols,hydrothermal temperature,and amount of NaOH,with CuSO4·5H2O and NaOH as main reaction sources.As a result,within the conditions studied the hydrothermal conditions to obtain micro/nano structure leaflike copper were D-sorbitol as reductive,molar ratio of polyol to Cu2+ equals to or less than 1/2,hydrothermal temperature 180℃,and no effect of amount of NaOH.
YUAN Hua, LI Zhou, ZHANG Guo-qing, XU Wen-yong, YAO Rui-ping, TIAN Shi-fan. Effect of Heat Treatments on Microstructure and Properties of Spray Formed Superalloy GH742y[J]. Journal of Materials Engineering, 2008, 0(1): 61-63,67.
The effects of different solution treatments on microstructure and properties of spray formed superalloy GH742y after forged were studied.The results showed that spray formed superalloy GH742y exhibited homogenous composition,segregation-free and fine microstructure.The grain size was about 35μm and hasn't changed with increasing temperature.The solvus temperature of γ′phase was about 1130℃.The shape and size of γ′phase were different,but mechanical properties of GH742y did not change after different heat treatments.The yield strength and stress rupture time of the alloy reached 1150MPa and 200h respectively in different heat treatments.
XU Si-xiang, WU Shu-sen, MAO You-wu, XIAO Yi. Parameters Optimization for Degassing Treatment of Magnesium Alloy Melt[J]. Journal of Materials Engineering, 2008, 0(1): 64-67.
Purging effects of Ar fluxing were investigated with an instrument for measuring hydrogen content in magnesium alloy melt,and the influence of three factors of Ar flow rate,degassing time and temperature of magnesium melt on purging effect were studied.The optimal parameters were obtained by experiment under conduction of orthogonal test design that Ar flow rate was 1-1.5L/min,degassing time 20-25min and temperature of magnesium melt 725-750℃.In addition,a series of parametric studies were conducted to demonstrate the influence of several key parameters on the effectiveness of purifying magnesium alloy melt.
LIU Wei-hong, CAO Chun-xiao, LI Yan, MAO Wei, LI Xiao-hong. Influence of Postweld Heat Treatment on Microstructure and Mechanical Properties of TIG Welded Joint of TD3 Alloy[J]. Journal of Materials Engineering, 2008, 0(1): 68-72.
TD3 alloy was welded by Tungsten Inert Gas(TIG)welding with a Ti-Al-Nb based alloy filler.The microstructure and mechanical properties of the base metal and the joint under postweld aging treatment condition and postweld solution plus aging treatment condition were investigated.The results showed that postweld solution plus aging treatment was relatively suitable for the joint.Heat affect zone and weld had the lowest tensile strength at room temperature and at 650℃,respectively.Due to the coarsening of the plated phase,the mechanical properties of the base metal with postweld solution plus aging treatment were lower than those with postweld aging treatment.
DU Nan, LU Xiong-wei, ZHAO Qing, WANG Mei-feng, ZHENG Gao. Effect of Anode Nozzle Caliber on Jet Flow Electrodeposition[J]. Journal of Materials Engineering, 2008, 0(1): 73-75.
A method of jet flow electrodeposition was established with watt nickel solution.The relationship between voltage and current,current density and current efficiency,nozzle caliber and effect of anode nozzle caliber on metal distribution were investigated.The deposits were uniform,coherent even the current density higher than 800A/dm2.The columnar deposit were got with diameters almost the same as nozzle caliber at 0.8,1.2,1.6mm.The current efficiency was strongly dependent on the nozzle caliber size.When nozzle caliber was 1.6mm,the current efficiency was 89.8%,nozzle caliber 0.8mm,the current efficiency only was 64.3%.
ZHANG Xiang-chao, YANG Hua-ming, TAO Qiu-fen. Development Trends in First-principles Calculation Simulation Study of TiO2-based Nanomaterials[J]. Journal of Materials Engineering, 2008, 0(1): 76-80.
The nature physics-chemical property and the present experimental investigation of nano-titanium dioxide(TiO2)was briefly introduced.The investigation progress of calculation simulation about the microstructure,photocatalysis and modification of TiO2-based nanomaterials using first-principles calculations based on density functional theory(DFT)had importantly discussed in detail.The problem existed nowadays and the development trends in this field were pointed out.
