YANG Cai-yun, TIAN Ling-ling, LIU Yong. Micro-design of Elastic Property for 3D Angle-interlock Structure Composites[J]. Journal of Materials Engineering, 2007, 0(8): 3-7,11.
An investigation is reported in which a geometric model based upon analyzing micrographs of sections for 3D angle-interlock structural composites was developed.The rectangular cross-section of the warp and the convex cross-section of weft were assumed in the geometric model.The predicting equations of equivalent engineering elastic constants were worked out according to variable parameters including seven structural parameters and elastic constants of fiber and resin using the stiffness averaging method and the geometric model.Equivalent engineering elastic constants predicting software of 3D angle-interlock structural composites were programmed,which provides three choices of weave structure,mechanical model and axis-off angle.Micro-design of elastic property for 3D angle-interlock structural composites is achieved basically.The experiment results show that both values of theory prediction of equivalent engineering elastic constants and experiments data are accordant.
LI Hong-yu, ZUO Ling-li, SONG Xi-ping, WANG Yan-li, CHEN Guo-liang. γ′ Particles Coarsening Kinetics in Nickel-base Superalloy GH742[J]. Journal of Materials Engineering, 2007, 0(8): 8-11.
FEG-SEM observation and quantitative phase analysis technique were employed to study the coarsening behavior and coarsening kinetics of γ′ particles after 900,950,1050℃ heat treatment in superalloy GH742.The results showed that with the increase of time,the number of small sphere γ′particles decreased meanwhile the big cube γ′particles increased because of the Ostwald ripening.The coarsening behavior of γ′particles obeyed the LSW theory at different temperature and the growth rate of γ′particles increased at elevated temperature.The activation energy of γ′particles coarsening in GH742 is(289.53±1.48) kJ /mol,which mean that the γ′ particles coarsening are controlled by the diffusion mechanics of the Al,Ti in the Ni matrix.
GAN Xue-ping, WU Ya-ting, HU Wen-bin, TANG Yi-wu. Study on Properties of Conductive PET Fabrics Prepared by Electroless Copper and Nickel Plating[J]. Journal of Materials Engineering, 2007, 0(8): 12-16.
Conductive Poly(ethylene terephthalate) (PET) fabrics were prepared by electroless copper and nickel plating.The surface resistance and electromagnetic interference(EMI) shielding effectiveness of the conductive fabrics were measured by four point probe method(ASTM F 390) and the coaxial transmission line method(ASTM D4935-99),respectively.Scanning electric microscope(SEM) analysis was used to observe the morphology of the fabric during the pretreatment and Cu/Ni-P coating growing process.The "Scotch tape test" was designed to measure the adhesion strength of the metal coating to the PET fabric.The change of breaking strength and elongation of the fabrics before and after metallization was evaluated by strip method according to GB/T 3923.1-1997.
YUAN Hong, YU Huai, WANG Jin-xue, WANG Xin-nan, ZHU Zhi-shou, LI Xiao-hong. The Damage Tolerance Properties of the EBW Joint for TC4-DT Titanium Alloy[J]. Journal of Materials Engineering, 2007, 0(8): 17-19.
The study on electron beam welding processing of thick-section TC4-DT alloy was carried out and the mechanical properties were valued.It results that TC4-DT alloy isan advanced structure material possessing of excellent EB weldability and outstanding damage tolerance properties of the joint such as the fracture toughness and the resistance to fatigue crack propagation.
QIAO Liang, JIANG Mei-yan, ZHENG Jing-wu, YOU Li-shun, JIANG Li-qiang. Sr-hexaferrites with La-Zn Substitution Prepared by Self-propagating High-temperature Synthesis[J]. Journal of Materials Engineering, 2007, 0(8): 20-23.
The La-Zn substituted SrM-type ferrites with the composition of Sr1-xLaxFe12-xZnxO19(x=0-0.4) were prepared by self-propagating high-temperature synthesis(SHS).The thermodynamic mechanism forming the different impurities of oxides containing Fe was analyzed according to the corresponding thermodynamic data.The results show that the single SrM-type ferrite can be achieved by controlling the Fe contents in the reagents.The substitution of La3+ and Zn2+ obviously increases the magnetic properties of the as-prepared samples.The maximum improvements of Br,(H)cb and(BH)m are 14.4%,15.3% and 30.7% respectively compared with that of the samples without La-Zn substitution.In comparison with the traditional firing method,the SHS method benefits forming the better particle features observed by SEM and achieving the higher (H)cj.
QIU Cheng-jun, LIU Hong-mei, ZHANG Hui-jun, ZHAO Quan-liang, MENG Li-na, CAO Mao-sheng. Research of Microactuator with PZT Prepared by Sol-gel[J]. Journal of Materials Engineering, 2007, 0(8): 24-27.
The PZT piezoelectric thin film was deposited on silicon substrates by using sol-gel techniques.The PZT thin films was used to fabricate V type valve microactuator by its piezoelectric response.As the key structure of microactuator,the preparation of multi-layer driving membrane structure for the Si/SiO2/Ti/Pt/PZT/Cr/Au solved the questions of problem of PZT deposited on silicon substrate.The problems of fabrication for the pump cavity and one-way valve fabricated by anisotropic etching are investigated and solved.The SEM photographs of V type valve and XRD analysis for the multi-layer driving membrane are given.The results show that the method integrating MEMS and IC technology to fabricating the microactuator is successfully.The pump cavity is flat and uniform.In the design of V type valve,the number of silicon slice is less and so the complexity is reduced to satisfying the desires of low power,minimizing and large number production.
SHAO Qian, YANG Yu-xiang, GE Sheng-song. New Activation Process About Electroless Nickel Coating on Cenospheres Surface[J]. Journal of Materials Engineering, 2007, 0(8): 28-31.
The composition of the nickel activation solution in water system without palladium and the process conditions of activation were studied through orthogonal tests.By this activation process,electroless nickel on cenospheres surface was carried out.The morphology of the cenospheres before and after coating was observed by scanning electron microscope(SEM),and its composition was determined by X-ray energy dispersive spectroscopy(EDS).
CHEN Hui-qin, LIN Hai, GUO Ling, CAO Chun-xiao. Hot Deformation Characteristics and Constitutive Relation of TC11 Alloy[J]. Journal of Materials Engineering, 2007, 0(8): 32-36.
Thermo-mechanical modeling tests of TC11 alloy with original β-transformed microstructure were carried out by hot compression in strain rate range 10-3-s-1 at the temperature range 1090-800°C.Stress-strain curves for different thermo-mechanical parameters were obtained.Parameters of stress exponents and deforming activation energies,which characterize the deformation capability and microstructure evolution,were calculated through analysis hot deformation behavior of the alloy.On the basis of the above,constitutive relation for hot deformation of the alloy were established.The results indicate that the established function relation is coincident with experimental data well.
DUAN Bo-hua, LIN Bing-tao, QU Xuan-hui, HE Xin-bo, CHENG Tong. Powder Injection Molding of 4J42 Invar Alloys[J]. Journal of Materials Engineering, 2007, 0(8): 37-40.
The parts of 4J42 Invar alloy were fabricated by powder injection molding with the Carbonyl Fe and Ni as powders and a wax-based polymer as binder.The debinding and sintering process in the PIM of Invar alloy were investigated.The results showed that all the binder could be removed rapidly with high efficiency after the solvent debinding and thermal debinding process subsequently.After sintered at 1350℃ under H2 atmosphere,the PIM Invar alloy with high properties was obtained,which the relative density,the average thermal expansion coefficient over the range of 30 to 300℃ and the leakage rate were 98.5%,4.5×10-6K-1 and lower than 1.4×10-9Pa·m3·s-1 respectively.The microstructure and X-ray diffraction both showed that the Invar alloy presented with only an austenitite phase(γ phase).
REN Xiao, ZHOU Wen-long, CHEN Guo-qing, HUANG Zhao-hui, ZHANG Jun-shan. Effect of High Magnetic Field on Intermetallic Compound Layers of Al-Cu Diffusion Couple[J]. Journal of Materials Engineering, 2007, 0(8): 41-44,78.
Interfacial intermetallic compound(IMC) layers of Al-Cu diffusion couple under high magnetic field were investigated.The results show that high magnetic field increases the thickness of the IMC layers and the species of the IMC layers changes with the intensity of high magnetic field.According to the parabolic law,the diffusion coefficients of the IMC layers were calculated.It can be concluded that the high magnetic field increases the diffusion coefficient,and the diffusion coefficient in the vertical directions are greater than those in the parallel ones.These results demonstrate that high magnetic field promotes the diffusion,thus enhances the formation and growth of the interfacial IMC layers.High magnetic field leads to the anisotropic diffusion in orthogonal directions.The above phenomena were preliminarily interpreted using the atom diffusion theory.
ZHANG Chang-song, GUO Chen-jie. Synthesis and Properties of Na0.5Bi0.5TiO3-K0.5Bi0.5TiO3 Lead-free Piezoelectric Ceramics[J]. Journal of Materials Engineering, 2007, 0(8): 45-48,52.
Na0.5Bi0.5TiO3-K0.5Bi0.5TiO3 lead-free piezoelectric ceramics was prepared by traditional method,the effects of different contents of K0.5Bi0.5TiO3 on the microstructure and electric properties of Na0.5Bi0.5TiO3-K0.5Bi0.5TiO3 ceramics were investigated.The results showed that Na0.5Bi0.5TiO3-K0.5Bi0.5TiO3 lead-free piezoelectric ceramics had the following properties with the K0.5Bi0.5TiO3 content increasing: lattice constant,dielectric constant and dielectric dissipation increased,density,particle size and mechanical quality factor decreased,piezoelectric constant increased firstly,and then decreased,curie temperature moved to higher temperature,and underwent a phase transition of ferroelectric antiferroelectric at 200℃.0.84NBT-0.16KBT ceramics is closed to morphotropic phase boundary(MPB) and has the best properties.
WANG Wen-jun, LI Yin, MEN Shuang, SHAO Zi-qiang. Structure and Properties of Cellulose Triacetate[J]. Journal of Materials Engineering, 2007, 0(8): 49-52.
Cellulose triacetate(CTA)was prepared in the presence of mixture of acetic anhydride/acetic acid/H2SO4.The structure and properties of cellulose triacetate acetylation were determined by IR,1H-NMR,XRD,DSC and chemical analysis.The results showed that acetyl mass fraction of all CTA samples were at least 60%,the most active reaction position on the anhydroglulose unit was C-6.Compared with that of cellulose,the crystallinity of CTA was much lower,but the processability was improved a lot.
LIAO Zi-jun, YAN Hua, CHEN Yong, CHEN Guo-xu. Synthesis and Properties of Barium Titanate/Polyaniline （BaTiO3/PAn） Complex Particle[J]. Journal of Materials Engineering, 2007, 0(8): 53-56.
The inorganic/organic complex particles of BaTiO3/PAn were prepared by the method of surface grafting polymerization,in which two kinds of silane couplings agent were used.The complex particles' morphology and structure were detected by SEM and XRD.The grafting on the surface between the two silane couplers and the barium titanate grain were optimized by the software Gaussian03.The results showed that the grafting polymerization was processed on the surface of BaTiO3,The results were verified by DFT.
CAI Jian-ming, LI Zhen-xi, CAO Chun-xiao, HUANG Xu, LEI Qiang, ZHANG Yuan-wei. Effect of Nd-rich Particles on Room Temperature Vibration Fatigue of Ti60 Titanium Alloy[J]. Journal of Materials Engineering, 2007, 0(8): 57-60.
The effect of Nd-rich particles on room temperature vibration fatigue of Ti60 titanium alloy was studied using vibration fatigue testing and scanning electron microscopy(SEM) methods.The fatigue life of blade specimens is strongly depended on the size and distributed state of Nd-rich particles.Increasing the size of the particles may enhance the fatigue crack initiation and reduce the fatigue life.The Nd-rich particles on the surface or sub-surface of blade enhance the crack initiation and decrease the fatigue life of the blade.
XIAO Feng, TAO Xin, LIAO Wei, LIU Lan-xiao, YANG Ren-hui, FU Ya. Wettability Analysis of Liquid Epoxy Resin-based Materials with Copper Substrate[J]. Journal of Materials Engineering, 2007, 0(8): 61-64.
The wettability of liquid epoxy resin-based materials with copper substrate was observed at 298-363K using a sessile drop method.The contact angle was measured,and the adhesion work was calculated.The contact angle tends to decrease with time elapsing in single experiment.The influence of surface roughness of substrate on contact angle is significant.The contact angle rapidly decreases and the equilibrium contact angle is small as the surface roughness is small.Both the original contact angle and equilibrium contact angle tend to decrease with increasing epoxy resin content in a sample.The adhesion work tends to increase with time elapsing,and it decreases with increasing temperature.
XU Chao, ZHANG Guo-dong, SU Bin. A Uniform Method for High Cycle Fatigue and Low Cycle Fatigue[J]. Journal of Materials Engineering, 2007, 0(8): 65-68,72.
Based on life prediction models for high cycle fatigue(HCF) and low cycle fatigue(LCF),a new method,i.e.uniform three-parameter strain energy function,was developed to characterize combing HCF and LCF.HCF and LCF data of superalloy GH141 at 760℃ was reduced by the method,the perfect energy-life equation was acquired.Except for superalloy GH141 case,the method was also valid for processing the combing HCF and LCF data of steel 1Cr11Ni2W2MoV at 500℃ and PM superalloy FGH95 at 600℃ respectively.
CAO Xiao-guo, ZHANG Hai-yan. Preparation and Performance of Silver-coated Carbonyl Iron Powder[J]. Journal of Materials Engineering, 2007, 0(8): 69-72.
Silver-coated carbonyl iron powder was prepared by using electroless plating method.Formaldehyde was used as reducer.The powder was characterized by XRD,SEM and EDX.Anti-oxidation was tested by TG.And SE of electromagnetic shielding material prepared with silver-coated carbonyl iron powders was investigated at the frequency range of 100kHz-1.5GHz.The results show that this method can prepare the integrative compact silver coating for silver-coated carbonyl iron powders.Oxidation resistance of carbonyl iron powders after being coated with silver was improved obviously.The SE of the electromagnetic shielding material is better than-32dB in the frequency range of 100kHz-1.5GHz.
MA Guang, WANG Guo-gang, SUN Dong-bai, FAN Zi-shuan, YU Hong-ying, MENG Hui-min, WANG Xu-dong. Investigation of Microstructures and Corrosion Resistance of Two Types of AC-HVAF Sprayed WC Coatings[J]. Journal of Materials Engineering, 2007, 0(8): 73-78.
WC-10Co-4Cr,WC-12Co coatings are prepared using advanced AC-HVAF spray on 0Cr13Ni5Mo stainless steel,the microstructures and corrosion resistance are investigated by XRD,SEM,electrochemistry and salt fog tests.The results show that the phases of the coatings are the same as that of the powers,W2C and W phases are not found,so the AC-HVAF spray technology can control the decomposition of the WC effectively;the coatings are well combined with the 0Cr13Ni5Mo stainless steel and the porosity rates are very low;electrochemistry and salt fog tests show that the corrosion resistance of the WC-10Co-4Cr coatings are better than WC-12Co coatings and 0Cr13Ni5Mo stainless steel;element Cr added in the binder and low porosity rate are the main reasons that the WC-10Co-4Cr coatings have high corrosion resistance.
ZHANG Jin-sheng, ZHAO Xu-hui, ZUO Yu, XIONG Jin-ping, ZHANG Xiao-feng. Effects of Deoxidization Processes on Adhesion Properties of Aluminum Alloys[J]. Journal of Materials Engineering, 2007, 0(8): 79-82.
The aluminum alloy samples were anodized in the phosphoric acid solutions and their adhesive properties were studied by the lap-shear test,peel test and wedge test.Prior to phosphoric acid anodizing(PAA),the alloy surfaces were deoxidized by alkali etching(AE),sodium chromic-sulfuric acid etching(FPL),sodium chromic-sulfuric acid-hydrofluoric acid etching(TAD),sulfuric acid etching(P2) or low volts phosphoric acid anodizing(LVPAA).The results showed that the adhesive bonding strength and durability of the alloy were influenced by the different deoxidization processes.Their adhesive bonding strength increased in the order: FPL>LVPAA>P2 or TAD>AE;their durability increased in the order: AE>LVPAA>FPL≈P2>TAD.Their comprehensive adhesive properties increased in the order: FPL or LVPAA>P2>AE or TAD.Because FPL solutions contain poisonous chromate,low cost and environment-friendly LVPAA and P2 methods are very promising.
