FAN Hai-bo, LIU Yan-lin, YANG Rong-jie, LI Xiang-mei. Compatibility and Thermostability Between Polyarylacetylene Composites and Polyhedral Oligomeric Silsesquioxanes[J]. Journal of Materials Engineering, 2014, 0(3): 1-6.
Polyhedral oligomeric silsesquioxanes (POSS) including octaphenylsilsesquioxane (OPS), octa(aminophenyl)silsesquioxane (OAPS) and octa(propargylaminophenyl)silsesquioxane (OPAPS) were used to prepare composite resins with pre-polyarylacetylene (PAA). The compatibility and thermal properties of the PAA/POSS composites were studied through SEM, XRD, FT-IR, DSC and TGA. The morphologies of PAA/POSS composites and XRD results proved that there was good compatibility between PAA and OPAPS because the terminal alkynyl groups in OPAPS could react with PAA, while the compatibility between PAA and OPS was the worst due to the OPS could deposit in the bottom of the composites. The FT-IR analysis indicates the formation of a conjugated diene and aromatic ring groups in the thermal curing processes of the resins. DSC analysis implies that the addition of inorganic silica-like core to prePAA decreases the exothermic heat. And incorporation of OPAPS could enhance the curing temperature a little. TGA analysis indicates that addition of OAPS or OPAPS would not reduce the excellent thermal stability so much and somewhat enhance the thermal-oxidative stability.
XUE Hong-qian, JIANG Yi-jun, FENG Shuo. Life Prediction of Ultrasonic Fatigue Crack Propagation of Nickel-based Alloy[J]. Journal of Materials Engineering, 2014, 0(3): 7-13,20.
According to the characteristics of engine structure materials under high frequency cyclic loading, the crack propagation of nickel-based alloy was studied using ultrasonic fatigue experimental system. Considering the temperature rising effect on the fatigue crack propagation under high frequency loading, the temperature changes were recorded in the fatigue test. The main effect of temperature rising was focused on changing of dynamic modulus of elasticity and coefficient of thermal expansion of nickel-based alloy. Based on these, the correctional stress intensity factor was calculated in keeping with the real experimental conditions. Then, the research on how the temperature rising influences the ultrasonic fatigue crack propagation was carried on, meanwhile, based on the current existing models, a model which considering temperature rising of ultrasonic fatigue crack propagation was given to improve the life prediction theory of fatigue crack propagation.
BAI Jiang-bo, XIONG Jun-jiang, GAO Jun-peng, YI Xiao-su. Effect of Gap Ratio on Elastic Properties of Triaxial Weave Fabric Composites[J]. Journal of Materials Engineering, 2014, 0(3): 14-20.
The effect of gap ratio on elastic properties of triaxial weave fabric (TWF) composites was numerically investigated by FEA method. Firstly, based on geometry construction and basic parameters of TWF composites, the relationship was determined between both surface density and feature length of representative unit cell and gap ratio. Secondly, the FEA model of TWF composites was established for predicting tension, compression and tear stiffnesses. The predicted results correlate well with experiments of the literature. Finally, the effect of the gap ratio on elastic properties of TWF composites was analyzed. It is found that the tension, compression and tear stiffnesses significantly decrease with the increasing of gap ratio, while the specific stiffness and Poisson's ratio change insignificantly.
HUANG Jian-kang, SHAO Ling, SHI Yu, GU Yu-fen. Pulsed DE-GMA Welding Brazing Lap Between Aluminum Alloy and Galvanized Steel and Properties of Lap Joint[J]. Journal of Materials Engineering, 2014, 0(3): 21-26,33.
Pulsed DE-GMA welding brazing was used for lap joining of aluminum alloy to galvanized steel using the filler wire ER4043. And the lap joints with good appearance, small deformation were obtained. Microstructure characteristics and mechanical properties of lap joints were researched by SEM, EPMA, EDS, micro-hardness tester and tensile experiment machine. The results show that at interface center of lap joints, acicular or zigzag FeAl3 is formed on aluminum side, and smoother Fe2Al5 and Fe0.7Al3Si0.3 are formed on steel side. Micro-hardness test further demonstrates that interface center of aluminum alloy and galvanized steel is composed of high hardness intermetallic compounds. It is got that average tensile-shear strength value of lap joints is 144.85MPa, and maximum tensile-shear strength value is 186.73MPa which is 88.5% of 5052 aluminum alloy. The mechanical properties of the mechanical test specimens present ductile fracture.
WANG Shao-hua, MA Zhi-feng, ZHANG Xian-feng, SUN Gang, FENG Zhao-hui, LI Wei, LU Zheng. Investigation on Microstructure and Properties of Al-Zn-Mg-Cu-Zr-0.5Er Alloy Profile[J]. Journal of Materials Engineering, 2014, 0(3): 27-33.
The microstructure and mechanical properties of Al-Zn-Mg-Cu-Zr-0.5Er alloy profile was studied using by optical microscopy (OM), scanning electron microscopy (SEM), electronic back-scattered diffraction technique (EBSD), transmission electron microscopy (TEM) and tensile test. Most of element Er in the alloy profile is the form of ternary Al8Cu4Er phase. The particles can strongly pin the dislocation and grain boundaries, and effectively restrain the recrystallization and grain increase of the alloy. Because the cracks initiate near remainder Al8Cu4Er phases due to the piling up of dislocation, the strength of the alloy profile decreases obviously.However,electrical conductivity increases slightly.
CHEN Xiao, WANG Hong-tao, JI Gang-chang, BAI Xiao-bo, WANG Yu-wei. Influence of Binder Phase Content on the Microstructure and Properties of HVOF Sprayed TiB2-Ni Coatings[J]. Journal of Materials Engineering, 2014, 0(3): 34-40,45.
TiB2-40Ni and TiB2-50Ni powder fabricated by mechanical alloying were sprayed by high velocity oxygen fuel(HVOF) to obtain TiB2-Ni coating. The microstructure and phase structure were analyzed by scanning electron microscope (SEM) and X-ray diffraction (XRD). The microhardness was measured by indentation method, the properties of thermal shock resistance and corrosion resistance to molten Al-12.07%Si alloy were investigated. The results show that both of coatings are compact, and their porosities are 1.25% and 0.12% respectively, the phase constitution of two coatings are TiB2 and Ni, the hardness of two coatings are (643.5±56.8)HV0.3 and (597.9±36.1)HV0.3 respectively. The coatings, especially TiB2-50Ni coating have excellent performance of thermal shock resistance. And two coatings have good durability in the molten Al-12.07%Si after 120h immersion test, TiB2-50Ni coating has better performance of corrosion resistance.
ZHAO Yan, CHENG Cong-qian, CAO Zhi-yuan, ZHAO Jie. Corrosion Property of Sn Interacted 304 Stainless Steel[J]. Journal of Materials Engineering, 2014, 0(3): 41-45.
Effect of low melting point Sn on electrochemical corrosion property of 304 stainless steel was investigated by potentiodynamic polarization test, galvanostatic polarization test and constant potential polarization test. The corrosion morphologies were observed using scanning electron microscope (SEM). Potentiodynamic polarization test and constant potential polarization test demonstrate that low melting point metal Sn adhered on 304 stainless steel surface accelerate substrate pitting formation, and the pittings increase with the increasing Sn amount. Galvanostatic polarization test illustrated Sn decrease the corrosion property due to the preferred corrosion Sn increase the acidity in the pittings.
LIU Wen-xiu, QUAN Hai-qin, LIU Xue-mei, ZENG Yan-ping, CAI Wen-he, ZHAO Wei-dong, CAO Wen-bin. Preparation and Properties of Visible Light-active Self-cleaning Porcelain Insulators[J]. Journal of Materials Engineering, 2014, 0(3): 46-49,54.
Using low-cost TiOSO4 as the starting material, a visible light-active nitrogen-doped N-TiO2 sol was prepared by the low-temperature hydrothermal crystallization method. Then the N-TiO2 sol, together with a SiO2 sol, was coated on the surface of porcelain insulators by the spraying technique, forming a N-TiO2/SiO2 composite film. After 8h illumination under visible light, the insulator sample had its photodegradation ratio of methyl orange in aqueous solution up to 90%. After 30min illumination under visible light, the contact angle between water and the composite film decreased from 28.2°to 7.4°, and this ultra-hydrophilic property could be maintained for 2-3 days in darkness. Taken together, the newly prepared composite film has good photocatalytic and self-cleaning abilities, which may help effectively reduce the occurrence of pollution flashover accidents.
CHEN Fei-fei, QI Le-hua, ZHOU Ji-ming, GUAN Jun-tao, XU Yi-ren. Design and Experiment Study of Micro-extrusion Forming System Based on Piezoelectric Actuator[J]. Journal of Materials Engineering, 2014, 0(3): 50-54.
A micro-extrusion forming system based on piezoelectric actuator has been developed. According to the actuality of short stroke and low nominal load for piezoelectric actuator, a sheave-lead screw-wedge mechanism was designed to achieve continuous extrusion by automatic feeding. Simultaneously, the warm forming process was adopted to improve metal formability and then expand the range of formable materials.With the forming system, micro-extrusion tests with micro ZnAl4 cylinders were carried out to verify its feasibility. The results show that it can achieves a good feeding effect and high forming efficiency when preload force has been adjusted to 2600N, under the cyclic working mode. What's more,the extrusion force to extrude ZnAl4 decreases about 50% when forming temperature increases from 230℃ to 270℃.
ZHANG Liang, HAN Ji-guang, HE Cheng-wen, GUO Yong-huan, ZHANG Jian. Effect of Thermal Cycles on the Interface and Property of SnAgCu(nano-Al)/Cu Solder Joints[J]. Journal of Materials Engineering, 2014, 0(3): 55-59.
Effect of nano-Al particle on interface reaction between SnAgCu and Cu substrate was investigated, and interfacial layer growth of the two solders and mechanical properties of solder joints during -55-125℃ thermal cycles were systematically analyzed. The results indicate that the intermetallic compounds grow obviously with the development of thermal cycles, Cu6Sn5 IMCs are found at the as-soldered interface, and Cu3Sn IMCs appears between Cu6Sn5 and Cu substrate during thermal cycles. Moreover, it is found that the addition of nano-Al particles can reduce the thickness of intermetallic compounds layer, and nano-Al particles can retard the IMCs growth during thermal cycles. Finally, the reliability of solder joints during thermal cycles was studied, the tensile force decreases with the development of thermal cycles, and the SnAgCu solder joints bearing nano-particles exhibits improvements compared to SnAgCu. In service, the failure path of solder joints is observed between Cu6Sn5 and Cu3Sn phases.
MA Yun, SHEN Li-da, TIAN Zong-jun, LIU Zhi-dong, ZHU Jun. Pulsed Friction Aided Jet Electro-deposition of Preparing Nano-crystalline Nickel[J]. Journal of Materials Engineering, 2014, 0(3): 60-65.
Nickel deposition layers were prepared by pulsed friction aided jet electro-deposition and DC jet electro-deposition on the substrate of graphite respectively, their surface micrograph, preferred orientation and average grain size were studied by SEM and XRD. The result indicate that comparing to DC jet electro-deposition, pulsed friction aided jet electro-deposition show better deposition effect. Under the condition that the nozzle flow rate is 200L/h, the average current density is 80A/dm2,the cathode rotating speed is 6r/min, when the pulse duty ratio is 50%, the pulse frequency is 2000Hz,smoother, brighter and more compact nickel-deposited layer can be obtained.
MA Xiu-ping, LI Chao. Effect of Superheat Temperature for Casting and Heat Treatment on Microstructure of CoCrMo Alloy[J]. Journal of Materials Engineering, 2014, 0(3): 66-70.
The effects of different superheat temperature and solution treatment on microstructure of shell mould casting CoCrMo alloy were studied. The results show that the carbides of as cast CoCrMo alloy exist in the form of eutectic M23C6. As the superheat temperature being enhanced, the size of carbides eutectic cells increases and tensile properties decline at room temperature. After solution treatment, most of primary blocky carbides are dissolved and small dimension M23C6 carbides are precipitated, uniformly distributing in the matrix. Tensile strength and yield strength and elongation are improved. Small dimension and uniformly distributed M23C6 carbides are to the benefit of improving the tensile properties at room temperature of CoCrMo alloy.
YANG Kun, HU Zhi-qiang, XU Shu-lin, WANG Hai-quan, YU Yang, LIU Gui-shan, JIANG Yan-yan, ZHANG Hai-tao. Preparation and Photoelectric Properties of ITO Films Deposited on PET Substrate[J]. Journal of Materials Engineering, 2014, 0(3): 71-76.
Transparent conductive indium tin oxide (ITO) films were prepared on flexible polyethylene terephthalate (PET) by pulsed magnetron sputtering. In order to gain the excellent electric conductive and optical transmittance properties, the effects of sputtering time, substrate temperature and deposition pressure on the ITO films were investigated, the crystal phase structure of ITO films was investigated by X-ray diffraction (XRD) and surface morphology was observed by scanning electron microscope (SEM). The results show that the average crystallite size grows with the increases of the substrate temperature. Both the sheet resistance and visible light transmittance decrease with the increases of the sputtering time. The sheet resistance decreases and visible light transmittance increases with the rises of the substrate temperature.
LI En-zhong, XU Bin-shi, WANG Hai-dou, GUO Wei-ling. Tribological Property of Polyetheretherketone Composites Reinforced with Glass Fiber Under Water Lubrication[J]. Journal of Materials Engineering, 2014, 0(3): 77-82,89.
The tribological behaviors of Polyetheretherketone(PEEK) reinforced with glass fibers(GF) have been investigated using the ball-on-disc configuration under dry sliding and water lubrication. The results indicated that the friction coefficient and specific wear rate of PEEK and GF/PEEK composites increased gradually and stabilized with the increase in applied load and grinding time under dry sliding and water lubrication. The friction coefficient and specific wear rate of PEEK and GF/PEEK under water lubrication were much lower than that of dry sliding. The wear of PEEK composite was characterized by adhesive and abrasive under dry sliding, while slight adhesive wear under water lubrication. The wear of GF/PEEK composite was characterized by adhesive and fatigue wear under dry sliding which severe GF failure/damage could be detected on the worn surfaces, while slight abrasive wear under water lubrication. The cooling and boundary lubricating effects of water hindered the melting of worn surface layer which caused a great improvement in the tribological characteristic. Moreover, the transfer between the counterface materials and the worn surface of the GF/PEEK was inhibited accounted for the decreased wear rate under water lubrication.
YAO Xiao-fei, XIE Fa-qin, WANG Yi-fei. Effects of pH Values on Corrosive Films Characteristics and Corrosive Behaviors of Super 13Cr Tubing Steels in NaCl Solution[J]. Journal of Materials Engineering, 2014, 0(3): 83-89.
The corrosive behaviors of super 13Cr tubing steels were investigated by an immersion corrosion test in NaCl solution with the different pH values, the scanning electron microscopy (SEM), energy dispersive analyzed (EDS), X-ray diffraction (XRD), mass loss, polarization and the electrochemical impedance spectroscopy (EIS) were employed to analyze corrosion morphologies, corrosion rate, corrosion products and electric characteristic of surface corrosive films. The results show that the corrosive films on super 13Cr tubing steels with passive characteristic, so which has good corrosion resistance properties in the acidic NaCl solution. With the pH values of NaCl solution decreased, the passive performance of the corrosive films on super 13Cr tubing steels corrosion increase, and the tendency of pitting corrosion decrease, and also the tendency of general corrosion increase. The corrosion products of super 13Cr tubing steels are consist of Fe and Cr oxides in acidic NaCl solution. When the solution pH values are greater than 4.5, the corrosion rate increase with the solution pH values decrease, when the solution pH values are less than 4.5, the corrosion rate decrease with the solution pH values decrease.
WANG Huai-yuan, MENG Yang, ZHAO Jing-yan, ZHU Yan-ji. New Progress on Preparation and Properties of Amphiphobic Surface[J]. Journal of Materials Engineering, 2014, 0(3): 90-96.
Surface wetting behavior is one of the most common phenomena in nature. As a particular state of wetting, amphiphobic surface has attracted extensive attention in recent years, and demonstrates great potential application in the purposes of hydrophobic, oleophobic, anti-pollution, self-cleaning and low friction. This paper systematically summarized various fabricating methods of amphiphobic surface, reviewed the current and latest progress in this field of research as well as prospective future developments.
