WANG Xun-qiu, JIANG Deng-gao. Surface Modification of Nano-CaCO3 and Its Application in Epoxy Modified Acrylic Primer[J]. Journal of Materials Engineering, 2006, 0(4): 3-7,11.
The surface of nanometer calcium carbonate was modified with compound modifiers. The influences of several factors on the property of nano-CaCO3,including modifier dosage,emulsification temperature,emulsification time and the time of being kept warm were investigated respectively.The technological conditions were optimized-modifier dosage was 4.83%(mass fraction)of nano-CaCO3,emulsification temperature was 80℃,emulsification time was 40min and the time of being kept warm was 60min.The active exponents,oil Absorption values,sedimentation volumes and the viscosities of the modified and unmodified nano-CaCO3 in dioctyl phthalate were measured.The FTIR characterizations of the modified and unmodified nano-CaCO3 were also carried out.The results showed that the lipophilicity of the modified nano-CaCO3 was increased remarkably.The nano-CaCO3 composite epoxy modified acrylic primer was prepared,compared with traditional epoxy modified acrylic primer,the modified nano-CaCO3 composite epoxy modified acrylic primer was remarkably improved in many aspects such as water,salt water and salt spray resistance.
ZHOU Yong-jiang, CHENG Hai-feng, CAO Yi, CHEN Zhao-hui, CAI Hong-nian. Study of Single Layer Radar Wave Absorbing Materials[J]. Journal of Materials Engineering, 2006, 0(4): 8-11.
The optimal complex permittivity of single layer ohmic lossy radar wave Absorber was explained in theory.The explanation revealed the Absorbing mechanism of single layer radar wave Absorbing materials(RAM).Single layer materials' electromagnetic parameters must decrease with frequency by rule to acquire strong Absorption in wide wave band.Iron powder/PVC RAM were tested and the results accordded with the theoretical analysis.The factors which influenced the performance of conventional single layer RAM are discussed.
LIU Feng, WANG Guo-jian, LIU Lin. Study on Water Dispersive Alkyd Resin[J]. Journal of Materials Engineering, 2006, 0(4): 12-15,36.
The water dispersive alkyd resin was prepared using the melting esterification polymerization.The appearance and stability of the water dispersive alkyd resin was improved.The end point of the esterification can be controlled by the acid value and 6mgKOH/g will be most proper.The water dispersive alkyd resins with different oil lengths were obtained using different fatty oils,and the proper kind of fatty oil and the proper oil length were determined by testing the properties of film.The results showed that the water dispersive alkyd resin made from synthenol has the best general properties and the most appropriate oil length is 50%.
ZHANG Zeng-zhi, ZHANG Li-mei, CHENG Hai-tao, NIU Jun-jie, ZHANG Ji-fei, LIU Ming, XU Hai-feng, HUANG Hua. Functional Film Using Coated Fibers to Adjust Soil Moisture[J]. Journal of Materials Engineering, 2006, 0(4): 16-20.
The coating of fibers was prepared for water penetration through a film with polyvinyl alcohol and laminar inorganic material in different proportion.The combination between the coating and fibers,and the fibers and matrix were analyzed through SEM and micrograms.The characteristics of water Absorbability and dehydration of the coating were illustrated with DSC and TG curves.The rate of water loss through WSCF(Water Storage and Controlled-release Film)was measured in environments at different temperatures and with different moisture.WSCF was also used for the field test,and the survival rate of afforestation was investigated. The results showed that the coating can improve the affinity between the fibers and resin matrix;the water penetration rate can be regulated by varying the proportion of the coating material;WSCF can adjust the water penetration rate according to the soil moisture suitable for plant growth in arid area;the survival rate of afforestation using WSCF is increased by 20%~50%,and the amount of growth is also improved.
LI Hui, QU Heng-lei, ZHAO Yong-qing, FENG Liang, ZENG Wei-dong. Effect of Lamellar Thickness on Fatigue Crack Growth Rate of TC21 Alloy of Damage Tolerance[J]. Journal of Materials Engineering, 2006, 0(4): 21-23.
The bars of TC21 alloy with a diameter of 90mm were produced by α+β and β processing.Under the same conditions,fatigue crack growth rate of bars produced by two different processing technics were investigated.Fatigue crack growth rate with fine and coarse lamellar structure were characterized.The results showed that material structure influenced the magnitude of crack propagation,microstructure with fine lamellar structure produced by β processing technic had a lower fatigue crack growth rate compared with the coarse lamellar structure produced by α+β processing technic,with the increasing of lamellar thickness,fatigue crack growth rate accelerated.In the stationary state growth region,fatigue crack grew ahead in the form of striation mechanism,many fatigue striations were observed by scanning electronic microscopy at the meantime.
XIANG Zhong-xia, DONG Gang, LIN Bin, SHEN Zhao-guang. Tribological Characteristics of Silicon Nitride-chilled Cast Iron with Oil-less Lubrication[J]. Journal of Materials Engineering, 2006, 0(4): 24-27,32.
The friction and wear tests for mated couples of silicon nitride(Si3N4)and chilled cast iron under the oil-less lubrication were carried out by means of block-on-disc with MG-200 wear machine from room temperature to 150℃,the friction coefficients of mated couples and wear rates of Si3N4 were gained,and the friction and wear behaviors were analyzed by the wear rates,friction coefficients,SEM images and percentages of chemical elements on worn surfaces.The results showed that the wear rate of Si3N4 and friction coefficient between Si3N4 and chilled cast iron with oil-less lubrication are much less than those with dry friction condition;the wear rate of Si3N4 increases with the increase of load and temperature,and the effect of sliding speed on wear rate of Si3N4 is not as significant as the effect of load;the friction coefficient between Si3N4 and chilled cast iron decreases with sliding speed,but increases with temperature,and the load has little effect on friction coefficient;the wear of Si3N4 is caused by interaction of chemical wear,abradant wear and particles' peeling off,and chemical wear is origin in other two.
LI Hong-ying, GENG Jin-feng, ZHANG Jian-fei, DONG Xian-juan. Influence of Ageing on Fracture Toughness and Stress Corrosion Cracking Resistance of B95ЛЧ Forging[J]. Journal of Materials Engineering, 2006, 0(4): 28-32.
The effect of two-stage ageing and retrograssion and reaging heat treatment(RRA)on the fracture toughness and stress corrosion cracking resistance of B95ЛЧ forging was studied.The fracture toughness,conductivity and strength under nine kinds of two-stage ageing treatment and three kinds of RRA treatment were measured.The results showed that the microstructure and property of the fracture toughness and stress corrosion cracking resistance increased with increase of ageing time and ageing temperature,when the condition of first order ageing treatment was identical.Of all two-step ageing treatment(115℃×7h+185℃×13h) was the best ageing one.Although RRA treatment could make B95ЛЧ forging the highest strength and stress corrosion cracking resistance,which can reach the level of the treatment(115℃×7h+185℃×13h)after twenty minutes of regression as well,the fracture toughness was lower.
LIU Wei-hua, JIA Cheng-chang, SHI Yan-tao. Study on Gelcasting of Fe-Cu-C Alloys[J]. Journal of Materials Engineering, 2006, 0(4): 33-36.
The application of the Fe-Cu-C alloys in gelcasting was discussed.Effects of the solid volume fraction and granularity on the drying rate and the shrinkage ratio were studied.Effects of the granularity on the maximal solid volume fraction were investigated.It is suggested that the process can obtain uniform structure and complex shapes of Fe-Cu-C alloys,the products have relative density of 90%,tensile strength of 365MPa and flexural strength of 1080MPa were prepared by gelcasting.
WANG Zheng, AN Mao-zhong, HU Xu-ri, XU Shu-min, GAO Zhen-guo. Electrodeposition of Zn-Ni-Sn Alloy[J]. Journal of Materials Engineering, 2006, 0(4): 37-40,55.
Electroplating Zn-Ni-Sn ternary alloy on electrolyte copper foil using alkaline salt pyrophosphate solution was investigated.Effect of bath composition,pH,temperature,current density on deposit were discussed,an appropriate additive was chosen,and polarization action was studied.Bath composition and process conditions for electroplating Zn-Ni-Sn ternary alloy were optimized.After the plating,corrosion resistance,heat resistance and binding strength of electrolyte copper foil were improved.
SUN Rong-xing, ZHANG Tong-jun, DAI Wei, LI Song. Comparison of Properties of TiB2 coatings and Ti-B-N coatings[J]. Journal of Materials Engineering, 2006, 0(4): 41-43.
TiB2 and Ti-B-N coatings were prepared by magnetron sputtering on 1Cr18Ni9Ti stainless steel.The microstructure and morphology of the TiB2,Ti-B-N coatings were investigated by field emission scanning electron microscopy(FESEM) and glancing angle X-ray diffraction(GAXRD).The microhardness of the films was tested and analyzed.The results showed that,when nitrogen was introduced,the surface of Ti-B-N coatings became very smooth,the structure of the coatings transformed from columnar nanostructure into amorphous state.The micro-hardness of Ti-B-N coatings decreased.Sliding friction and wear investigation were also performed at room temperature without lubrication.It is found that the friction coefficient of the Ti-B-N coatings is lower than that of the TiB2 coatings,but the wear resistance doesn't show improvement.
FENG Yong, SHI Hua, XIONG Jia-jin, LU Feng. Influence of Esterification Degree of Amine Salt of Alkyl Phosphate on Thin Film Intumescent Coating[J]. Journal of Materials Engineering, 2006, 0(4): 44-47,51.
The effect of the esterification degree of amine salt of alkyl phosphate on the intumescent coating was studied through the small scale fire tests,TG and DSC method.The results showed that the fireproofing performance of the coating increased as the esterification degree of the organic phosphate increased,and the duration of fire resistance also increased as the esterification degree of the organic phosphate increased.When the experimental time reached 120min,the higher esterification degree gained the lower back temperature of the sample and forms the foamed char with better heat insulation.The lower esterification degree of the organic phosphate reduced the mass loss of the sample at high temperature,when the argon was used as the carrier gas.
LIANG Chun-lei, LI Xiao-yan, GONG Shui-li, CHEN Li. Study on Fatigue Property of Laser Welded Joints of TC4 Titanium Alloy Sheet[J]. Journal of Materials Engineering, 2006, 0(4): 48-51.
The tensile and fatigue properties of TC4 titanium alloy sheet and its laser welded joints were investigated.The results showed that the strength of laser welded joints was increased and the elongation rate was decreased compared with base metal.The tensile fracture of laser welded joints was found on base metal.The fatigue life of laser welded joints was higher than that of base metal under low stress levels,nevertheless,the fatigue life of laser welded joints was lower than that of base metal under high stress levels.In fatigue crack expansion zone,base metal was tough transgranular fracture,however,a mixed fracture characteristics of tough and brittle was noted on fractographs of fusion zone.In transient crack zone,the SEM fractographs of base metal consisted of equal-axis ductile voids,the fusion zone was mainly consisted of course transgranular cleavage facets.
QIAO Min, LI Shu-suo, MA Wen-you, SONG Jin-xia, HAN Ya-fang. Effect of Content of Al on Microstructure and Mechanical Properties of Ni3Al Base Alloy IC6E[J]. Journal of Materials Engineering, 2006, 0(4): 52-55.
In order to determine the optimum content of Al,alloys with the different amounts of Al(0%,0.4%,0.6%,0.8%)based on the master alloy composition of Ni-14.0Mo-7.2Al-0.025B(mass fraction/%) were prepared.The tensile strength at room temperature and stress rupture life at 1050℃/90MPa have been determined. The microstructures of the alloys have been studied by scanning electron microscopy.On the basis of the compromise of the microstructures and mechanical properties,the optimum content of Al was determined to be 7.8%.
ZHOU Heng-zhi, LI Zi-quan, WANG Ling, YANG Yu-ling, LI Zu-ze. Effect of Surfactant Span80 and Accelerant on Electrorheological Properties of TiO2/Methlsilicone Oil[J]. Journal of Materials Engineering, 2006, 0(4): 56-59,66.
Coating process that the micron and nano-TiO2 particles with anatase structure were covered with non-ion surfactant Span80 was investigated by liquid-coating method.The relationship between the static shear stress of TiO2/Methlsilicone oil system with different formulations τ and external electric field E was determined experimentally.The results showed that the particles were covered completely by Span80.The surfactant improves the dispersion and suspension of coated TiO2,that the Span80 layer on the particles promotes the polarization of the electrorheological(ER) fluid,that the addition of suitable accelerant enhances ER properties,and that mixture of small amount of nano-TiO2 in micron TiO2/silicone oil increases the shear-resistant stress of ER fluid.
ZHAI Yan-qiang, LI Ke-zhi, LI He-jun, LIU Hao, ZHAO Jian-guo. Surface Modification Technologies and Biological Response Properties of Bioactive Coatings on Carbon/Carbon Composites[J]. Journal of Materials Engineering, 2006, 0(4): 60-66.
Carbon/carbon composites preserved the inherent excellent biocompatibility of carbon.Their mechanical properties can be tailored to be similar to those of bone.Carbon/carbon composites were considered to be promising materials for orthopedic and dental surgery.However,it had no bioactivity and fails to form chemical bond with host bone.Bioactive coatings on carbon/carbon composites substrate can improve its bioactivity and reduce occurrence of carbon debris.The coating technologies and biological properties of bioactive layers on carbon/carbon composites were reviewed.The current research situations and problems concerning carbon/carbon composites in artificial bones were discussed.The means to solve these problems and the prospects of carbon /carbon composites in artificial bones were predicted.It was believed that surface modification in implantation of carbon/carbon composites should promote its application in artificial bones.
