2014 Vol.34(6)

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2014, 34(6): 0-0.
[Abstract](118) [PDF 3692KB](1)
Research Advances and Industrialization Prospects of All-Solid-State Thin-Film Lithium Battery
CHEN Mu, YAN Yue, LIU Wei-ming, ZHOU Chen, GUO Zhi-qiang, ZHANG Xiao-feng, WANG Yong-lin, LI Lei, ZHANG Guan-li
2014, 34(6): 1-20. doi: 10.11868/j.issn.1005-5053.2014.6.001
[Abstract](376) [PDF 6994KB](15)
As a new generation of Li-ion battery, rechargeable all-solid-state thin-film lithium batteries (TFLBs) employ solid electrolyte to replace traditional liquid electrolyte and are fabricated on plane substrates using layered thin films. Potential applications include dual-use flexible wearable devices, portable electronic devices, vehicle and aircraft power batteries, etc. In academic society and industry community, it is widely accepted that the ultra-safe batteries own long cycle life, high specific capacity and high energy density. This article reviews basic operation principles and classifications of TFLBs, summarizes the development history of cathode/electrolyte/anode materials, their preparation process and electrochemical performance. Three representative directions in recent research advances are discussed: three-dimensional TFLBs, flexible batteries, high-voltage and large-capacity battery packs.Foreign commercial battery products, key technology and battery fabrication equipment are shown in details. Possible directions of domestic R&D and industrialization are pointed out.
Superplastic Constitutive Relationship of TA15 Titanium Alloy Based on Strain Rate Circulation Method
TAN Li-qin, WANG Gao-chao, GAN Wen-qing, XIONG Cheng
2014, 34(6): 21-27. doi: 10.11868/j.issn.1005-5053.2014.6.002
[Abstract](303) [PDF 2733KB](2)
The superplastic deformation behavior of TA15 titanium alloy was performed based on the strain rate circulation using superplastic tensile testing machine in the temperature range 850-900℃, and the strain rates range 5×10-6- 5×10-4 s-1. The dynamic recrystallization activation energy was obtained through the analysis of the tensile experimental data, and the conclusion about dynamic recrystallization occuring during the thermal deformation was given by combining microstructure analysis. The constitutive relationship of the TA15 titanium alloy based on the Arrhenius model was established, the data was analysed using origin data processing software, then the constitutive equations about TA15 titanium alloy under high temperature conditions was obtained. 1stopt software was used to fix the constitutive equations, and an accuracy of 99.3% was obtained. The results show that the flow stress of TA15 titanium alloy is sensitive to the deformation temperature. With the increase of temperature, flow stress decreases and softening mechanism increases. The titanium alloy superplasticity is the best at around 900℃ with the elongation reaching 846%.
Effect of ECAP at Room Temperature on Microstructure and Properties of T250 Maraging Steel
XIE Dong, YANG Xi-rong, ZHAO Xi-cheng, XI Sha
2014, 34(6): 28-32. doi: 10.11868/j.issn.1005-5053.2014.6.003
[Abstract](210) [PDF 2971KB](1)
The microstructure changes of T250 maraging steel during equal channel angular precessing (ECAP) were studied,and the change of hardness with aging time was analyzed.T250 maraging steel was deformed by route C ECAP process 2 deformation at room temperature. And then, as-received samples and ECAP samples were aged at 480℃ for 15-480min. The results show that with the increase of ECAP pass, the microstructure of x plane changes from a more uniform neat lath into a more curved messy one.Then the subgrains and the dislocation cells appear in the lath.The change of y plane is refinement of martensite laths,and the microstructure of z plane is not changed.The hardness of T250 maraging steel is gradually increased with the increase of passes,and the increasing percentage of hardness by aging treatment is declined,meanwhile the time to maxmize hardness is shortened.
Effect of Heat Treatment on Fatigue Properties of AZ80 Magnesium Alloy
LI Yi, LI Hui-zhong, JIANG Jun, YANG Jie
2014, 34(6): 33-39. doi: 10.11868/j.issn.1005-5053.2014.6.004
[Abstract](271) [PDF 5277KB](1)
Through the experiment of low cycle fatigue experiment of AZ80 magnesium alloy under the total strain amplitude control at room temperature, cyclic stress response, fatigue life and the cyclic stress-strain behavior was studied under the heat treatment of hot forging, aging state (T5) and solid solution-aging state (T6). The results show that AZ80 magnesium alloy is generally characterized as the cyclic strain hardening phenomenon under three heat treatments. In addition, the relationship between the fatigue life and the plastic strain amplitude or the elastic strain amplitude obeys the Coffin-Manson or the Basquin equation for AZ80 magnesium alloy respectively. With the increase of total strain amplitude, the fatigue life reduces. Under the minimum total strain amplitude of 0.3%, the fatigue life of hot forging state is the longest; under the maximum strain amplitude of 0.9%, the fatigue life of AZ80-T5 is the longest and hot forging state is the shortest. Moreover, the observation of the fatigue fracture morphology shows that the fatigue cracks initiate in the sample surface, and extend in a transgranular manner.
Optimization of Microstructure and Properties of Cu-Ag-Zr Alloy
REN Xiu-feng, YIN Zhong-wei, DENG Tai-qing, CHEN Yong-lai, TU Gang
2014, 34(6): 40-46. doi: 10.11868/j.issn.1005-5053.2014.6.005
[Abstract](262) [PDF 3425KB](1)
Effects of solution-aging and thermal-mechanical treatment on the microstructure and properties of Cu-3Ag-0.5Zr alloy were studied by tensile tests, metallography, SEM and EDS, and the optimal heat treatment technology was obtained. The results indicate that the Cu-3Ag-0.5Zr alloy possesses the best combination of strength and toughness under the condition of solution treatment at 940℃ for 40min(water cooling) and aging treatment at 500℃ for 2h(air cooling). The tensile strength, yield strength and elongation of Cu-3Ag-0.5Zr alloy treated by the optimal heat treatment process are 289MPa, 124MPa and 37.6% respectively. The pre-aging deformation and the precipitation are attributed to the high strength. The tensile strength, yield strength and elongation of Cu-3Ag-0.5Zr alloy deformed by 40% are 421MPa, 350MPa and 16.7%, respectively.
Preparation and Microstructure of Nb/Nb5Si3 Microlaminated Composites
HUANG Guang-hong, SHEN Zao-yu, MU Ren-de, HE Li-min, CHANG Zhen-dong
2014, 34(6): 47-53. doi: 10.11868/j.issn.1005-5053.2014.6.006
[Abstract](208) [PDF 2679KB](1)
Nb/Nb5Si3 microlaminated sheet was prepared by ion beam assisted electron beam physical vapor deposition technology(EB-PVD). The composites and microstructure of Nb/Nb5Si3 were analyzed by XRD and SEM. The structure and morphology of microlaminated materials prepared under the different conditions of EB-PVD were investigated. The microlaminated materials were synthesized by vertically incident, high electron beam and high temperature with the double-target deposition method. The results indicate that the prepared material with visible lamellar structure is composed of cubic Nb and Tetragonal Nb5Si3 phases. The degradation of columnar grain was investigated after annealing under the condition of 1200℃/3h. It is shown that after vacuum heat treatment, the columnar grain structure is transformed to equiaxed grain structure in microlaminated material.
Process Parameters of CCF300/5228A Composites by RFI Process
CHEN Wei, CHENG Li, ZHANG Chen-qian, LI Cha, YE Hong-jun
2014, 34(6): 54-61. doi: 10.11868/j.issn.1005-5053.2014.6.007
[Abstract](201) [PDF 3737KB](1)
The molding process parameters of modified 5228A epoxy resin system specially used in RFI were studied by the manufacture of CCF300/5228A composite laminates. The RFI molding processes were divided into two basic processes: fiber infiltrated process and resin curing process. The viscosity-temperature characteristics, infiltrating pressure and compacting property of CCF300 fibrous material were studied during fiber infiltrated process. The curing kinetics and curing process parameters were discussed. Results show that the modified 5228A epoxy resin can meet the requirement of RFI process. The best fiber infiltrated process parameter of CCF300 reinforced modified 5228A composite is (125±3)℃,(0.1±0.02)MPa, 90min. The best curing process parameter is (0.5±0.02)MPa, (190±3)℃, 90min.The heating rate is maintained at 1~1.5℃/min in the whole process.
Fabrication and Performance of Shape Memory Epoxy Resin Composite
HE Xian-cheng, GAO Jun-peng, AN Xue-feng, YI Xiao-su
2014, 34(6): 62-66. doi: 10.11868/j.issn.1005-5053.2014.6.008
[Abstract](284) [PDF 1030KB](3)
The carbon fiber reinforced epoxy resin composites with shape memory effect were manufactured via vacuum-bag curing process. The deformation-recovery shape memory tests of composite were performed above Tg of the resin matrix. The results show that the shape fixation rate of the composite decreases from 98% to 91% and the recovery rate decreases from 98% to 91% while the mass fraction of carbon fiber increases from 0% to 50%. The shape fixation rate and recovery rate of the composite does not show any obvious and regular changes in the limited cyclic test.
Fracture Toughness Based on Test Method for Straight-Notch CT Specimen
YAO Yao, CAI Li-xun, BAO Chen, SHI Kai-kai, WU Hai-li
2014, 34(6): 67-74. doi: 10.11868/j.issn.1005-5053.2014.6.009
[Abstract](302) [PDF 3021KB](2)
Systematic investigation on the estimation of J resistance curves for straight-notch CT specimens was carried out on the basis of normalization method which concludes in the non-dimensional load separation method. Improvements on the load separation principle were performed. In the light of refined finite element analyses and the geometry deformation relationship of straight-notch CT specimen, a transforming formula from crack mouth opening displacement (V0) to load line displacement (VLL) was proposed. Blunt cracked CT specimens with different initial crack length were used to test and verify the transforming formula. Three types of engineering materials, such as 1Cr12Mo, 30Cr2Ni4MoV and 10Cr9Mo1VNbN, were employed to estimate the J-resistance curves. The results show that the errors between the experimental and calculated values are all less than 5%.
Fatigue-Life Prediction Method Based on Small-Crack Theory in GH4169 Superalloy
ZHANG Li, WU Xue-ren
2014, 34(6): 75-83. doi: 10.11868/j.issn.1005-5053.2014.6.010
[Abstract](231) [PDF 3846KB](3)
Fatigue life prediction method based on small crack theory was used on GH4169 superalloy to calculate fatigue lives under constant-amplitude loading conditions. The growth behaviors of natural-initiated small fatigue cracks in single edge notched specimens of GH4169 superalloy under stress ratios of 0.1 and 0.5 at room temperature were studied. All small cracks initiate from the inclusions on specimen surface, and most of the total fatigue lives are cost on the phase of small crack propagation. Small crack effects are significantly shown in the zone of crack growth rate lower than 10-5 mm/cycle. According to the Newman crack closure model, the da/dNKeff baseline data were obtained based on the long-and small-crack growth data. The fracture morphology of high cycle fatigue specimens were observed and analyzed. The results show that the fatigue cracks initiate from typical inclusions of the material on specimen surfaces. The initial crack size, ai, from the inclusion size, is obtained from analysis on specimen fracture surfaces. Based on the initial crack size and the baseline data, the total fatigue lives of GH4169 superalloy were predicted using FASTRAN software. The prediction results were evaluated by high cycle fatigue test data. Results from the tests and prediction agree well for both R ratios.
Experimental and Numerical Study of Progressive Failure of TC4 Titanium Alloy Specimens
LIU Chao, SUN Qin, LIU Yan-jie
2014, 34(6): 84-89. doi: 10.11868/j.issn.1005-5053.2014.6.011
[Abstract](220) [PDF 3300KB](0)
To predict the progressive failure behavior of ductile metals, a series of experiments were conducted for smooth and notched specimens of titanium alloy TC4. And numerical simulations were performed with the GTN damage model based on ABAQUS/explicit. Meanwhile, different numerical simulations with or without geometric non-linearity were studied by contrastive analysis. Results show that the GTN damage model can accurately and effectively predict the experimental results of TC4 specimens including load-displacement curves and macroscopic fracture morphology.
Semi-Analytic Numerical Method for Free Vibration before Thermal Post-Buckling of Functionally Graded Material Euler Beams with Surface-Bonded Piezoelectric Layers
SU Hou-de, FAN Jian-ling, YU Shu-rong, FENG Yu-jie, CAO Wei-guo
2014, 34(6): 90-97. doi: 10.11868/j.issn.1005-5053.2014.6.012
[Abstract](204) [PDF 651KB](2)
Free vibration before thermal buckling of functionally graded material Euler beams with surface-bonded piezoelectric layers subjected to temperature rise and electric field were studied. By accurately considering the axial extension in the sense of theory of Euler beam, geometrically nonlinear governing equations, for functionally graded beams subjected to thermo-electro-mechanical loadings, were formulated. In the analysis, it was assumed that the material properties of the beam vary continuously as a power function of the thickness coordinate and that the piezoelectric layers are isotropic and homogenous. By using a shooting method to solve the linearized equations, a semi-analytic numerical method is proposed to predict the free vibration behavior of the beams with the fixed and simply supported edges subjected to transversely non-uniform heating and uniform electric field. Due to being transversely non-uniform in the material properties, there exists tension-bending coupling effects on the beam even in uniform temperature and electric rise in the thickness direction, which could impact the natural frequencies to some extent.

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