XU Xiao-jing. Superplasticity of SiCW/LY12 Composite Made by Pressure Infiltration[J]. Journal of Materials Engineering, 1999, 0(5): 3-5.
The superplastic characteristics of the beta-SiC whisker reinforced LY12 aluminum composite,fabricated by pressure infiltration and hot-rolling after extrusion with a low extrusion ratio,were investigated.The results show that the SiCW/LY12 composite exhibit a total elongation of 200%~370% in the initial strain rate region from 3.3×10-3 to 3.3×10-2 s-1at 788~808K.
CHEN Xin-wen, XU Feng-he. Study of Absorption Characteristics of T300/5405 Composites[J]. Journal of Materials Engineering, 1999, 0(5): 6-8.
The experiments of T300/5405 composites immersed in 60,80and 100water nearly for 900h were developed respectively.The moisture content-time curves were obtained.What's more,the effects of water temperature on the Diffusion Coefficient Dx and the Balanced Moisture Content Mb were discussed too.Thus,a foundation were created for researching absorption behavior of T300/5405.
SHI Rong, LI He-jun, KANG Mo-kuang, HU Geng-xiang. Damping Properties of Loose 1-D-C/C Composites Prepared by CVI[J]. Journal of Materials Engineering, 1999, 0(5): 9-11.
Damping properties of several loose unidirectional carbon/carbon(1-D-C/C) composites were measured by a self-made multi-functional damping apparatus using twisting method.The composite specimens manufactured by chemical vapor infiltration (CVI) method were reinforced by two different kinds of carbon fibers,namely high modulus carbon fibers (T-50) and high strength carbon fibers (T300).The results show that the damping values of the loose 1-D-C/C composites decrease with the increase of their densities.Under the same process condition,the damping values of 1-D-C/C composites reinforced by T-50 are higher than those reinforced by T300.Moreover,there appear sharp damping peaks between 80~200 in the damping curves of the former unidirectional composites.Carbon fiber types and interface microstructures are the main factors that affect damping properties of this kind of 1-D-C/C composites.
LI Pei-yong, DAI Sheng-long, LIU Da-bo, CHAI Shi-chang, LI Yu-ren. An Investigation on Microstructure and Properties of Low Density Damping Metal/Metal Composite Materials[J]. Journal of Materials Engineering, 1999, 0(5): 12-15,19.
Al-7.09%Fe-1.34%Mo-1.45%Si(FMS0714) alloy,and its composite materials FMS0714/15%Al and FMS0714/10%(Zn-30%Al) were successfully developed by the rapid solidification/powder metallurgy (RS/PM) process.Their microstructure,tensile properties,damping capacity and density were investigated,and compared with those of LD7CS wrought aluminum alloy.The results show that FMS0714 alloy itself possesse good tensile properties and damping capacity.Addition of pure Al and Zn-30%Al alloy powders to FMS0714 alloy,its strength is lowered,but its elongation is slightly improved.In the temperature range of 20~250,the damping capacity of FMS0714/15%Al is close to that of FMS0714;while the damping capacity of FMS0714/10%(Zn-30%Al) is better than that of them.Among them,the damping capacity at 20 of FMS0714/10%(Zn-30%Al) was up to 8×10-3,approaching to the damping level of high-damping metals and alloys.The densities of these materials are lower than 3.1 g/cm3,and their tensile strength and damping capacity are superior to that of LD7CS alloy.These materials can be used in place of LD7CS alloy on airplanes,where vibration is needed to be attenuated.
ZHU Zhi-shou, ZHONG Ming, CHU Jun-peng, WANG Qing-ru. Static Recrystallization Behaviors of Cold Rolled β-21S Titanium Sheet[J]. Journal of Materials Engineering, 1999, 0(5): 16-19.
The recrystallization behaviors of a new metastable β-type titanium (β-21S) sheet have been investigated and the optimum solutioning process has already been developed.The results show that,in order to acquire a microstructure with fine recrystallization grain size,a cold rolling reduction at least 55% is needed.With increased cold rolling reduction,the recrystallization starting temperature drops down and the minimum time for recrystallization fulfillment decreases.All the results lay a foundation for determination of cold rolling procedures and solutioning treatment processes.
CHENG Yu-hang, ZHAO Jian-sheng, WU Yi-ping, CHEN Jian-guo, QIAO Xue-liang. The Structure of 65MnV Steel for Quenching Ejector Pins of Plastic Dies[J]. Journal of Materials Engineering, 1999, 0(5): 20-22,26.
The dependence of microstructure of newly developed plastic die ejector pins steel 65MnV on quenching temperature and tempering temperature was studied.The results show that the quenching structure of 65MnV steel is mainly composed of dislocation martensite.With the increasing of quenching temperature,the structure changes from the composition of needle and plate martensite to needle martensite,the microstructure of martensite changes from dislocation to twin.carbide is precipitated in 65MnV steel at low tempering temperature.The decomposition of carbide and precipitation of M3C carbide can be observed at higher tempering temperature.
ZHANG Hua-yu, HAN Jie-cai, ZHANG Wei-fang, DU Shan-yi. Investigation of TiC-Al2O3-Fe Cermet by SHS[J]. Journal of Materials Engineering, 1999, 0(5): 23-26.
Densified TiC-Al2O3-20Fe cermet was produced by self-propagating high temperature synthesis and pseudo-hot isostatic pressing(SHS/PHIP).The composition,microstructure and properties of the product were analyzed.The results show that the cermet consists of TiC and Al2O3 particles and quasi-continuous Fe-binder phase.The interfacial bonding between Fe and Al2O3 is smooth.Transverse rupture strength and compressive strength are approximately 890MPa and 18.4GPa.
SU Zheng-tao, LIU Jun, KONG Yi, WANG Hong-rui. Study on the Properties of Methyl(3,3,3-Trifluoropropyl)Siloxane-dimethyl Siloxane Copolymer[J]. Journal of Materials Engineering, 1999, 0(5): 27-28,31.
The properties of methyl(3,3,3-trifluorpropyl)siloxane-dimethyl siloxane copolymer has been investigated in this paper.The coefficient of coldresistance for the copolymer under compression is 0.73 at -60℃ and 0.59 at -70℃,while fluorosilicone rubber is 0.12 at-55℃ and 0.03 at -60℃.The glass transition temperature(Tg) of the copolymer is -84.4℃,while that of fluorosilicone rubber is -62.4℃ determined by loss modulus of DMTA.
LI Bang-sheng, JIANG Hai-yan, ZHANG Bao-you, LI Qing-chun, YUAN Guang-jiang, MI Guo-fa. Microstructure and Mechanical Properties of XD ZL201/TiB2P Composites[J]. Journal of Materials Engineering, 1999, 0(5): 29-31.
The composites of submicron TiB2 reinforced ZL201 were fabricated by XD process,and the microstructures and mechanical properties were studied by TEM,SEM and so on.The results show that mechanical properties of the composites reinforced by TiB2P with 0.1~0.4μm diameter are raised obviously compared with ZL201 matrix.
ZHANG Yu-min, HE Xiao-dong, HAN Jie-cai, DU Shan-yi. Study of Ceramic Green Tape Extrusion for LOM[J]. Journal of Materials Engineering, 1999, 0(5): 32-35.
Al2O3 and SiC green tape with 02mm thickness used for LOM were prepared from a 48vol% ceramic suspension in a LDPE based organic vehicle by extrusion technique.Rheological characterization of alumina suspension was performed.Differential thermal analysis and SEM micro-structure analysis of green tape were completed.
LUO Chun-rong, LI Yan, ZHAO Xiao-peng, CHEN Ru. Preparation of ER Fluid Made up of Composite Particles and Their Properties[J]. Journal of Materials Engineering, 1999, 0(5): 36-38.
In this paper,SiO2/P(MMA-MAA)microcapsule composite particles are prepared and a new ER fluid made up of composite particals and silicon oil are prepared also.The mechanical property and material property of the ER fluid are tested.The results show that the composite particles improve the stability of ER fluid and the shearing strength of ER fluid increases with the increasing electric field strength.
YAN Feng, WANG Xiao-guang. Study on the Crystalline Property of WOx Films with HREM and STM[J]. Journal of Materials Engineering, 1999, 0(5): 39-42.
The crystalline property of reaction sputtering deposition WOx films,caused by electrochromic reaction,was studied with HREM and STM techniques.The HREM results show that electrochromic reaction increases the crystal property of the films,and SAD of WOx films in bleached and colored states is of crystal-ring,and in deposited state is of amorphous-halo.The STM results disclose that electrochromic reaction make a great change in the morphology of films.
CAI Shan, SUN Chang-yi. Distribution Character of Tensile Strength and Intrinsic Defects in Boron Fibre[J]. Journal of Materials Engineering, 1999, 0(5): 43-46.
The relation of distribution character of tensile strength and intrinsic defects in boron fibre are described by single weibull distribution function and the different mechanism of fracture.The results show that the distribution of tensile strength of intrinsic defects having different mechanism of fracture fit single weibull distribution,and have each particular shape and parameter.Then the intrinsic defects in boron fibre are classified and described by statistical means.
DAI Jie-quan, TAO Chun-hu. Fracture Analysis of Casting Titanium Alloy Shuttling Bar[J]. Journal of Materials Engineering, 1999, 0(5): 47-48.
Casting titanium alloy shuttling bar can work under alternative load with the frequency 5Hz.Fracture occurs in a casting bar after only 200 hours in the course of service.In this paper,fracture analysis has been performed and it reveals that stress concentration by weld defects is an essential reason of fatigue fracture.
