XIONG Guo-xuan, ZENG Dong-hai, ZHOU Yu-fen, LU Chun-hua. Study on Properties and Synthesis of Polymer Schiff Base with Ferrocene and Bi-thiazole[J]. Journal of Materials Engineering, 2008, 0(11): 1-4.
The DABT was synthesized with 2,3-butanedione,liquid dibromine,and thiourea and the ferrocenyl schiff base was synthesized by DABT and ferrocenecarboxaldehyde.Then polymer of ferrocenyl schiff base was prepared by the Friedel-Crafts method,their metal complexes were made by doping Fe2+,Ni2+ and Cu2+ sulfates.Their structures were characterized by infrared spectra and 1H-NMR spectra,conductivity and magnetism properties were measured with a Four-point probe Instrument and gouy magnetic balance.The experiment results showed that the synthetical product was polymer of ferrocenyl schiff base,its conductivity was 1.61?10-6 S·cm-1 belonging to semiconductor.Magnetism properties of metal complexes by doping Fe2+,Ni2+ and Cu2+ sulfates were obviously higher than polymer of un-doping,and properties of complexes by doping Cu2+ sulfate was best.These porperties indicated they can be applied as a new organic functional electromagnetism material.
WANG Jun-li, SHI Qing-nan, WANG Xiao-qi. Study on Microstructure and Orientation Evolution of Ultra-fine Grained Copper Prepared by Asymmetrical Accumulative Rolling Bonding (AARB) During Annealing[J]. Journal of Materials Engineering, 2008, 0(11): 5-8.
The uniform ultra-fine grained copper was prepared by asymmetrical accumulative rolling bonding(AARB)and anneal.Microstructure and orientation evolution of samples after AARB and subsequent anneal were investigated.The deformed and annealed states were characterized by electron back scatter diffraction(EBSD)orientation image microscopy(OIM)and TEM.It was shown that there are many defects and substructure in the copper which is processed by AARB for six passes.The ultra-fine grained copper with the grain size of 200-500nm is obtained when deformed copper is annealed at 220℃ for 35-55min.Grains with all kinds of orientations exist together and some special orientations is not obvious.Elongation rate of UFG-Copper is increased.
ZHANG Shou-ming, WANG Song, CHEN Zhao-hui. Effect of Slurries on the Microstructure and Mechanical Properties of Cf/SiC Composites via Precursor Pyrolysis[J]. Journal of Materials Engineering, 2008, 0(11): 9-12.
Cf/SiC composites were fabricated by Precursor Infiltration and Pyrolysis(PIP)with three different slurries.This paper studied the effects of the slurries on the microstructure and mechanical properties of their composites.It is pointed that the composites infiltrated with the slurry of PCS/cross-linking agent had a density of 1.78g·cm-3 and a open porosity of 4.95%,and its fabrication was only made of 9 times of infiltration and pyrolysis;The second composites infiltrated with PCS/Xylene/SiC had the highest density of 1.87g·cm-3 with smooth surface;And the last composites took on outstanding mechanical properties,the values of flexural strength,flexural modulus and fracture toughness were 455.9MPa,90.6GPa and 18.9 MPa·m1/2respectively.The results indicate that different slurries have different advantages,the composites could obtain the best characteristic if it was infiltrated with the most appropriate slurry in every fabrication circles.
LIU Hui-xia, ZHANG Hui-zhong, DING Guo-min, WANG Xiao. Research on Laser Transmission Welding HDPE[J]. Journal of Materials Engineering, 2008, 0(11): 13-18.
The influence of laser transmission welding parameters for HDPE on welding quality was investigated by method of orthogonal design.Tensile and section tests were conducted for experimental samples,and the influence of welding factors on shear strength and welding seam size was analyzed,which indicated subsequence according to influence for HDPE was welding velocity →laser power→cooling time→beam diameter on the material→laser frequency →fixture pressure,and high laser power density can result in coking on samples’faces and fake fracture appeared when welding seam was not even.The optimized welding parameters were determined using range method.
QU Chun-yan, XIE Ke-lei, MA Ying-jian, WANG De-zhi. Preparation and Characterization of Polymethacrylimide Foams[J]. Journal of Materials Engineering, 2008, 0(11): 19-23.
Polymethacrylimide(PMI)foams were prepared by the casting process using methacrylic acid(MAA)and methacrylonitrile(MAN)as monomers.The structure and properties of the PMI foams were analyzed by infrared adsorption spectrum(FTIR),optical microscope,differential scanning calorimeter(DSC)and thermogravimeter(TG).The results show that the foamable MAA/MAN copolymers were prepared at 40-60℃ by polymerizing the mixture of 50phr MAA,50phr MAN,1-5phr magnesium oxide,2-8phr butanol and tert-butanol,0.2-0.3phr dibenzoyl peroxide and tert-butyl perbenzoate and 0.1-0.2phr DMF.Then the resulting copolymers were expanded at 200-220℃ for 2-3h,subsequently treated at 160℃ for 5-6h,generating PMI foams with excellent mechanical properties and heat-resistance.Molecular rearrangement reaction occurs during the foaming and post-treatment forming hexahydric imide ring.The prepared PMI foams have closed cell structure with the cell size ranging from 0.5mm to 0.7mm and have a good thermostability with the characteristic degradation temperature at about 221.5℃.
CUI Da-wei, JIANG Jun-sheng, WEN Xiao-shuo, QU Xuan-hui. Rheological Properties of Feedstock for Metal Injection Molding of High Nitrogen Austenitic Stainless Steel[J]. Journal of Materials Engineering, 2008, 0(11): 24-27.
High nitrogen austenitic stainless steel was prepared by metal injection molding,and the effect of viscosity of feedstock consisted of paraffin wax(PW),high density polyethylene(HDPE),polypylene(PP)and aric acid(SA),as well as shear rate and temperature on the viscosity was investigated.And the influence of polymer components on the rheological behavior of feedstock was also compared.The results showed that the feedstock exhibited better rheological properties when the binder was made of 65%PW,30%HDPE and 5%SA,which is more suitable as the organic vehicle for MIM of high nitrogen austenitic.
CHEN Yu-hua, KE Li-ming, XU Shi-long, XING Li. Study on the Micro Laser Welding Parameter of Ultrathin Stainless Steel Sheet[J]. Journal of Materials Engineering, 2008, 0(11): 28-31.
Butt welding of 0.2mm thick 321 stainless steel sheet was realized using micro impulse laser.The processing parameters were optimized by orthogonal experimental and influence of processing parameter on the morphology and microstructure of welded joint was studied.The results show that the optimized processing parameters that can get the maximum stretching resistance are:pulse power percentage is 15,pulse frequency is 5 Hz and pulse width is 2.1ms.With the optimized processing parameters,the stretching resistance of the welded joint can achieve 95% of base metal.Burn through in welded seam is easy to occur when laser pulse energy is too big and nonpenetration occurs when pulse width is too small.Both burn through and nonpenetration can lead to the decrease of stretching resistance.The microstructures of welded joint that has best stretching resistance are composed of equiax crystals in weld center and fine columnar crystals in weld edge.
ZHOU Shu-cai, LEI Ya, LI Hua-ji, REN Zheng-de, CAO Peng-jun, YANG Zhi-li. Effect of Low-frequency Electromagnetic-field on Macrostructure of Continuous Casting Austenitic Stainless Steel[J]. Journal of Materials Engineering, 2008, 0(11): 32-35,40.
The influence of low-frequency electromagnetic-field on macrostructure of austenite stainless steel in horizontal continuous casting was investigated based on industrial experiment.The results show that application of appropriate electromagnetic stirring parameters can improve the macrostructure of austenitic stainless steel,in which both columnar grains and equiaxed grains are evidently refined and center porosity and shrinkage cavity can be remarkably decreased,and enlarging equiaxed grains zone.The industrial trials verify that the stirring intensity of austenite stainless steel should be higher comparing with plain carbon steel.Electromagnetic stirring has somewhat affected the macrostructure of the austenitic stainless steel even if the the magnetic flux density of the electromagnetic stirring reaches average 90mT(amplitude reaches 141mT)in average at frequencyf=3-4Hz.Due to a higher viscosity,rotating speed of molten stainless steel was 20%-30% lower than that of molten carbon steel in the same magnetic flux density.
YAN Shao-ping, JIANG Bai-ling, SU Yang, BAI Li-jing, LONG Yan-ni. Study on Heat-resistance of Magnetron Sputtered Cr/C Coating[J]. Journal of Materials Engineering, 2008, 0(11): 36-40.
Magnetron sputtered Cr-C coatings were treated at different temperatures in the air furnace.The variation of phase structures,microhardness and adhesion of coatings at different temperatures were investigated in order to evaluate the thermal stability of Cr/C coating.The results indicated that:Cr-C coatings presented high microhardness,adhesion and good thermal stability below 600℃.The dense chromium oxide and carbide formed during the coating heated,which hindered the diffusion of oxygen atoms to the inner layers and elevated the destabilizing temperature highly,as a result,a fine heat-resistance presented.The microhardness and adhesion of coatings decreased notably after the processing temperature reached 800℃.
WANG Xiao-xian, LI Tie-hu, JI Yong-bin, JIN Wei. Preparation and Characterization of Ordered Mesoporous Carbon Membranes[J]. Journal of Materials Engineering, 2008, 0(11): 41-45.
Novel carbon membranes with a hexagonal structure were fabricated directly by the carbonization of sulfuric-acid-treated surfactant/silica nanocomposite membranes and subsequent silica removal.The nanocomposite membranes were prepared by dip coating technique through a combination of sol-gel and evaporation-induced self-assembly process.The samples were characterized by field emission scanning electron microscopy(FESEM),transmission electron microscopy(TEM),N2 adsorption-desorption,and thermogravimetric analysis(TGA).These analyses reveal that the carbon membranes are composed of carbon nanotubes arrays and have continuous,smooth and ordered symmetric structure.The surfactant triblock copolymer P123 has dual functions in the sol-gel process.One is the structure directing and the other is carbon precursor.Pretreatment with sulfuric acid is a key step to improve the carbon yield of P123 and to stabilize the structure of carbon membranes.At the same time,by varying the aging temperature of nanocomposite membrane,it is possible to control the size of ordered carbon membrane.
LIU Ping, YANG Jun-hong. Digital Visible Spectrum Analysis of Co in Ni-based Alloy[J]. Journal of Materials Engineering, 2008, 0(11): 46-48.
The digital analysis method was developed for visible spectrum of cobalt in Ni-based alloy.The researches were carried on the character of Co481.35nm and Co645.02nm line groups in Ni-based alloy.The quantitative analysis and the identification of alloy mark was studied on cobalt in Ni-based alloy by digital analysis system.The results can meet the qualitative analysis and the quantitative analysis on cobalt in Ni-based alloy,which also can be used to exactly examine alloy mark.
YANG Jian-wei, ZHANG Lei, DING Rui-ming, LU Min-xu. Study On H2S/CO2 Corrosion Behavior of Pipeline Steel in Wet Gas[J]. Journal of Materials Engineering, 2008, 0(11): 49-53,58.
Flowing wet gas environments containing H2S/CO2 were simulated in a high temperature and high pressure autoclave.Corrosion behaviors of API-X52 and API-X60 pipeline steels were investigated with Scanning Electron Microscopy(SEM)and X-ray Diffraction methodology(XRD).Effects of high H2S partial pressure on corrosion rate and products were discussed.Corrosion rates of both steels increased with the H2S partial pressure increasing in wet gas,and the corrosion rate of X60 was appreciably higher than that of X52.Localized corrosion was obviously observed when the H2S partial pressure up to 2.0 MPa.The corrosion process was controlled by H2S and mackinawite(FeS1-x)was the dominant corrosion product.Hydrogen blistering and hydrogen-induced cracking were also occurred in X60 in wet gas.
YU Zhi-guo, CHAI Ya-nan, SONG Bi-feng. Experimental Study on Strength of Non-stitched/Stitched Skin-to-Stiffener Structures[J]. Journal of Materials Engineering, 2008, 0(11): 54-58.
Stitch is an important way to enhance fracture toughness and connection.In order to validate its enhancement effect comparing to traditional bond structures,two groups of stitched/non-stitched composite T-shaped and L-shaped skin-to-stiffener performs were designed,and check experiment on the strength of non-stitched/stitched skin-to-stiffener structures,loaded in tensile pull-off,was performed.The results show that the stitched L-shaped specimen strength increased by 93.4% averagely,while the stitched T-shaped specimen did not improve.Reasons for the case were analyzed basing on experimental phenomenon.
YU Xiao-dong, WANG Yang-wei, WANG Fu-chi, ZOU You-rui, GAO Ju-bin. High Volume Fraction SiC Particles Reinforced 2024Al Composite Prepared by Squeeze Casting[J]. Journal of Materials Engineering, 2008, 0(11): 59-62.
High volume fraction composites were produced by infiltrating liquid aluminium into preforms made by mixing and packing SiC particles with average diameters of 200 and 10μm.The maximum particle volume fraction 75%(volume fraction)was obtained for a mixture having 80%(mass fraction)of coarse particles.The influence of preform’s oxidation treatment on mechanical properties of the composites was studied.The results showed that the bending strength and fracture toughness of the composite which was fabricated from the un-oxidation treatment preform were 288MPa and 8.7MPa·m1/2respectively.The relative density of the composite after oxidation treatment was lower,so as to the bending strength and toughness.But the oxidation treatment has little effect on the hardness of the composite,and the hardness of both composites was about HRA 70.The main failure mechanisms of the composite were the crack of the coarse particle and the debonding of the interface between fine particle and the matrix.
SONG Dan, ZHOU Ji-dong, JIANG Wei, ZHANG Xiao-juan, LI Feng-sheng. Synthesis of Monodisperse Metal-coated Polystyrene Conductive Microspheres with Ultrasonic Assisted[J]. Journal of Materials Engineering, 2008, 0(11): 63-67.
Monodisperse Ni/polystyrene conductive microspheres were prepared by electroless plating with ultrosonic assisted.Then a film of Au was coated onto the surface of the Ni/PS conductive microspheres via displacement reaction.The transformation of functional group,modality,elemental composition,crystalline structure of the resin microspheres and conductive microspheres were characterize by FI-IR,SEM,EDS and XRD.The results show that ultrasonic wave improved the dispersion of conductive microspheres,which have regular sphericity.The coating was sequential and uniform with nanosized mound-like protuberance on it.After coated by Au film,the electrical resistivity of conductive microspheres can get to 6.9×10-3Ω·cm,which can satisfy the parameter requirement of ACF.
LI Li, ZHU You-li, LU Guang-yi, HUANG Yuan-lin, BAI Chang. Study on Ultrasonic Deep Rolling Surface Mechanical Enhancement Technique of TC4 Titanium Alloy[J]. Journal of Materials Engineering, 2008, 0(11): 68-70,74.
A new developed surface mechanical enhancement technique,Ultrasonic Deep Rolling(UDR),was introduced.UDR was used to treat TC4 titanium alloy specimens.Residual stress and work hardening distribution,surface profile and surface roughness of the specimen were analyzed.Results show that a deep layer of high value compressive residual stress with moderate work hardening was developed.Surface roughness was reduced substantially.Advantages and potential applications of the UDR technique were discussed.
ZHANG Rong-fa, CHAO Qiang-hua, ZHAO Fang, WANG Wei, NIE Xin-bing, ZHOU Chong, ZHANG Hong, HU Chang-yuan, ZHU Guang-yu. Applied Stats of Phytic Acid in Protection of Magnesium Alloys[J]. Journal of Materials Engineering, 2008, 0(11): 71-74.
Phytic acid,an innoxious and organic phosphate,is separated from cereal crops.Owing to fast reaction with many metal ions such as Ca2+,Mg2+,Fe2+ and Zn2+ to form chelate compounds,phytic acid can be used in protection of metals.This paper reviews the applications of phytic acid in conversion coating and anodizing on magnesium alloys.As an environmentally friendly and effective treating agent,phytic acid has a good application prospect in protection magnesium from corrosion.
SUN Ying-di, LI Zi-quan, SHEN Ping, SHAO Bin. Current Progresses in Bulk Mg-based Amorphous Alloys and Their Composites[J]. Journal of Materials Engineering, 2008, 0(11): 75-79.
The new development in bulk Mg-based amorphous alloys and their composites is mainly reviewed,and some progresses in selection of compositions and the new criterions of glass forming ability(GFA)for bulk metallic glass are briefly analyzed and summarized.Based on problems in Mg-based amorphous alloys,research in future are suggested.
