WANG Kai-guo, LI Jia-rong, CAO Chun-xiao. Present Situation of Study on Creep Behavior of Single Crystal Superalloys[J]. Journal of Materials Engineering, 2004, 0(1): 3-7,11.
The present situation of research on creep behavior of the single crystal superalloys was reviewed.The mechanism of directional coarnsening of γ',the creep anisotropy and the dislocation evolution during creep were analyzed and the study direction of creep behavior of the single crystal superalloys was approached.
LI Xing-wu, ZHANG Qing-ling, SHA Ai-xue, CHU Jun-peng, MA Ji-min. Effect of Deformation Temperature on Microstructure and Properties of TA15 Alloy[J]. Journal of Materials Engineering, 2004, 0(1): 8-11.
The effect of deformation temperature on microstructure and properties of TA15 alloy with laminated original microstructure was studied.The results show that the tensile strength,elongation and area reduction increase with deformation temperature decreasing,and the microstructure is laminated when the upset test specimen is deformed in β phase field.The degree of dynamic recrystallization deformed at 1080℃ is higher than that at 1030℃ in severe or free deformation area of upset test specimen.The transition structure is obtained when the upset test specimen is deformed in α+β phase field.There is considerable difference in the microstructures between severe or free deformation area and hard deformation area.
ZHU Li-qun, ZHANG Wei, LIU Feng. Study on Properties of Composite Copper Coating with Microcapsule[J]. Journal of Materials Engineering, 2004, 0(1): 12-15.
Properties of the composite copper coating with liquid microcapsule were studied.Corrosion resistance and wear resistance of the liquid microcapsule composite copper coating was evaluated by 25% ammonia,10% HNO3 corrosion testing,and wear testing.The results show that the electrodepositing composite copper coating with liquid microcapsule has good corrosion resistance and wear resistance.
LI Yun-tao, DU Ze-yu, HE Xiao-dong. Effect of Cold Work on Sulfide Stress Corrosion Cracking for Domestic Pipeline Steel X70[J]. Journal of Materials Engineering, 2004, 0(1): 16-19.
SSRT(Slow Strain Rate Test)was adopted to study the effect of cold work on the SSCC(Sulfide Stress Corrosion Cracking)of pipeline steel X70 in the sulfide solution.The results show that the cold work plays an important role in corrosion of high strength pipeline steels,it will bring about a deal of microstructure change all that are in state of higher energy.Hydrogen atoms aggregate easily on those locations,and hydrogen permeation increases.Meanwhile,higher strength caused by cold work is increased,but toughness is decreased.Finally,the corrosion resistance for domestic pipeline steel X70 is decreased by the interaction of stress and hydrogen.
JING Xin-li, WANG Yang-yong, ZHANG Dong-hua. Preparation and Properties of Silicon Dioxide/Polyaniline Composite Particles[J]. Journal of Materials Engineering, 2004, 0(1): 20-24.
Polyaniline(PANI)was formed preferentially on the surfaces of silicon dioxide particles,which resulted in PANI coated silicon dioxide composite particles(SD/PANI),when aniline(ANI)was polymerized through chemical oxidative polymerization with the presence of silicon dioxide particles.Scanning electron microscopy(SEM)and transmitting electron microscopy(TEM)examinations showed that smooth PANI layer with thickness of 10～60nm was formed with lower ANI content in reactants;while with higher ANI content,the PANI layer showed particulate appearance.UV-VIS spectra and X-ray photoelectron spectroscopic(XPS)analyses have indicated that oxidation state of PANI on the surfaces of silicon dioxide particles decreased with the content of silicon dioxide particles in reactants.PANI layer adhered firmly to the surface of silicon dioxide particle and the composite particles passivated the cold rolled steel(CRS)as the pure PANI did.
JIAO Bao-xiang, QIU Tai, SHEN Chun-ying, XU Jie. Study on Rheological Behaviors of Slurryfor ZTA Ceramics by Gelcasting[J]. Journal of Materials Engineering, 2004, 0(1): 25-28.
The effect factors on rheological behaviors of ZTA ceramic slurries in gelcasting process were investigated.The results show,when the mass fraction of AM is 10% and the ratio of MBAM to AM is low in liquid,the viscosity of suspensions is low;the viscosity and shear stress of slurry reduce with the increase of dispersant agent,the rheological behaviors of the suspension follow Herchel Bulk model;the grain size of ZrO2 raw material has an important influence on the rheological behaviors of the suspension,the fine grains of the raw material determine the behaviors of ZTA suspension;in the experiment,the best mill time is 9h.
CHENG Xiang-zhen, XIAO Jia-yu, XIE Zheng-fang, SONG Yong-cai. Research on Curing of Polycarbosilane Fiberand Preparation of SiC Fiber[J]. Journal of Materials Engineering, 2004, 0(1): 29-32,37.
The polycarbosilane(PCS)which is the precursor of SiC fiber was synthesized in an autoclave by thermal decomposition of polydimethylsilane(PDMS).PCS fiber was obtained by melt-spinning.The influence of curing time at 190℃ on the weight gain,Si-H bond reaction degree,gel content,and oxygen content of PCS fiber was investigated.The cured PCS fibers were then pyrolyzed up to 1250℃ at a tube furnace in a N2 flow.The oxygen content and properties of SiC fibers were determined.The results show that Si-H bond in the molecular structure of PCS reacts with oxygen during the curing process.Si-O-Si linked structures are therefore produced among PCS moleculars.The weight gain,Si-H bond reaction degree,gel content,and oxygen content of PCS fiber increase with increase of the curing time.The oxygen content of SiC fiber increase gradually also.When the PCS fiber is cured for 3 hours and pyrolyzed,the tensile strength of SiC fiber can reach 2.52 GPa,and decreases gradually when the curing time is more than 3 hours.
AI Yun-long, LIU Chang-hong, ZUO Dun-wen, WANG Min. Preparation and Toughened Mechanism of ZrO2/SiC-WSi2/MoSi2 Nanocomposite Ceramics[J]. Journal of Materials Engineering, 2004, 0(1): 33-37.
The relations of ZrO2/SiC-WSi2/MoSi2 composite powder dispersion,hot pressed sample microstructure,fracture morphology and fracture toughness were investigated by scan electronic microscope,image analysis instrument and X ray diffraction.The results show that nano/micron particles can be dispersed effectively using ball milling,ethanol cleaning,ultrasonic surging,and coacervation of them is decreased.SiC,ZrO2 nanoparticle composite and W alloying can induce composite ceramics fine grain,toughen greatly,and fracture toughness is up to 8.13 MPa·m1/2.The fracture presents most intercrystalline assistant with some transcrystalline.Composite ceramics can be toughened by fine grain,crack deflection,microcrack forming and bridge union.
MENG Mian-wu, LIU Xin-yu, CHENG Jun, ZHOU Huai-ying. Phase Composition and Thermal Stability of LaNi5-41%MgAlloy Prepared by High Energy Ball Milling[J]. Journal of Materials Engineering, 2004, 0(1): 38-41.
The LaNi5-41%Mg(mass fraction)alloy was prepared by the high energy ball milling,the phase composition and thermal stability of the alloy were investigated by means of the X-ray diffraction(XRD),scanning electron microscope(SEM),differential thermal analysis(DTA).The results show that,besides small amounts of Mg and Mg2 Ni phases,the amorphous La,Mg,Ni can be obtained after ball milling at 280r/min for 250h,and the shape of particles is spheroid or sphere.The size of particles is 0.1～15.2μm.After heat treatment at 763K for 35d,the as-milled LaNi5-41%Mg alloy is stable and consists of Mg2NiLa,Mg2Ni,Mg17La2 phases with the average grain size of 26.9nm.
LEI Yu, WANG Yu-lin, WAN Yi-zao, ZHANG Zong-qiang, ZHENG Li-yun. Study on Friction and Wear Properties of Fiber ReinforcedNylon Composites[J]. Journal of Materials Engineering, 2004, 0(1): 42-45,41.
The friction and wear properties of the continuous fiber and 3-dimension braided fiber reinforced nylon-matrix composites were investigated under different conditions.The worn surfaces and wear debris were observed and analyzed.The results show that the wear resistance of the composites increases with the increase of the carbon fiber volume fraction under dry friction.Wear rate of 3-D braided carbon fiber reinforced MCPA(C3D-/MCPA)composites is lower than that of continuous carbon fiber reinforced MCPA(CL/MCPA)composites.Friction coefficient and wear rate of C3D/MCPA composites under water friction are almost 50 percent of that under dry friction.Wear rate of 3-D carbon/Kevlar hybrid fiber reinforced MCPA(HF/MCPA)composites decreases with the increase of the carbon fiber volume fraction,but its friction coefficient has no significant change.
LI Yue, TAO Ye, LIU Pei-ying, ZHANG Qin, ZHANG Tong-he. Wave Absorbing Property and Mechanism of Nano-surface-modifiedFiber Reinforced Resin Based Composite[J]. Journal of Materials Engineering, 2004, 0(1): 46-48.
Nanometer modified films was formed on the surface of the fiber by vacuum plasma.The resin matrix composite was reinforced by the modified fibers.The electro-magnetic property and wave-absorbing property of the composite were tested.The results show that the wave-absorbing property of the fiber reinforced composite can be effectively improved by nano-surface modification.The reflectivity of the composite is-(2.6～6.1)dB in 8～18 GHz.The wave-absorbing curve has such character as wide wave-absorbing frequency.The mass increment of the material is almost zero.
