期刊文献+
共找到109篇文章
< 1 2 6 >
每页显示 20 50 100
Predict the evolution of mechanical property of Al-Li alloys in a marine environment
1
作者 Wei Li Lin Xiang +6 位作者 Guang Wu Hongli Si Jinyan Chen Yiming Jin Yan Su Jianquan Tao Chunyang Huang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第1期557-566,共10页
The ocean is one of the essential fields of national defense in the future,and more and more attention is paid to the lightweight research of Marine equipment and materials.This study it is to develop a Machine learni... The ocean is one of the essential fields of national defense in the future,and more and more attention is paid to the lightweight research of Marine equipment and materials.This study it is to develop a Machine learning(ML)-based prediction method to study the evolution of the mechanical properties of Al-Li alloys in the marine environment.We obtained the mechanical properties of Al-Li alloy samples under uniaxial tensile deformation at different exposure times through Marine exposure experiments.We obtained the strain evolution by digital image correlation(DIC).The strain field images are voxelized using 2D-Convolutional Neural Networks(CNN)autoencoders as input data for Long Short-Term Memory(LSTM)neural networks.Then,the output data of LSTM neural networks combined with corrosion features were input into the Back Propagation(BP)neural network to predict the mechanical properties of Al-Li alloys.The main conclusions are as follows:1.The variation law of mechanical properties of2297-T8 in the Marine atmosphere is revealed.With the increase in outdoor exposure test time,the tensile elastic model of 2297-T8 changes slowly,within 10%,and the tensile yield stress changes significantly,with a maximum attenuation of 23.6%.2.The prediction model can predict the strain evolution and mechanical response simultaneously with an error of less than 5%.3.This study shows that a CNN/LSTM system based on machine learning can be built to capture the corrosion characteristics of Marine exposure experiments.The results show that the relationship between corrosion characteristics and mechanical response can be predicted without considering the microstructure evolution of metal materials. 展开更多
关键词 Marine environment al-li alloy Machine learning CORROSION
下载PDF
Characterization of localized corrosion pathways in 2195-T8 Al-Li alloys exposed to acidic solution 被引量:4
2
作者 De-jun Liu Gan Tian +2 位作者 Guo-feng Jin Wei Zhang You-hong Zhang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第7期152-165,共14页
The corrosion properties of aluminum-lithium(Al-Li) alloys, which are potential materials used to construct for tanks of liquid rockets or missiles, are essential for safe propellant storage and transport. In order to... The corrosion properties of aluminum-lithium(Al-Li) alloys, which are potential materials used to construct for tanks of liquid rockets or missiles, are essential for safe propellant storage and transport. In order to manifest the corrosion resistance of the 2195 Al-Li alloy in practical propellant tanks filled with N2O4, the alloy was soaked in 30% nitric acid solution, an accelerating corrosion environment, to test its corrosion behavior. Scanning electron microscopy(SEM) and transmission electron microscopy(TEM)were used to characterize microstructure and corrosion morphology of the alloy. Focused ion beam(FIB),combined with SEM, was used to demonstrate localized corrosion features and the propagation of corrosion pathways beneath the alloy surface. It was found that the corrosion network was formed with most intergranular corrosion and sparse intragranular corrosion. Additionally, the distribution and number of intermetallic particles influenced the localized corrosion degree and the direction of corrosion pathways. Aggregated particles made corrosion pathways continuously and caused more severe corrosion. The results from this work were valid and useful to corrosion prevention and protection for storage safety on propellant tanks in N_(2)O_(4). 展开更多
关键词 al-li alloy Corrosion behavior Corrosion features Immersion test Intermetallic particles
下载PDF
Fatigue Life Estimation of High Strength 2090-T83 Aluminum Alloy under Pure Torsion Loading Using Various Machine Learning Techniques
3
作者 Mustafa Sami Abdullatef Faten NAlzubaidi +1 位作者 Anees Al-Tamimi Yasser Ahmed Mahmood 《Fluid Dynamics & Materials Processing》 EI 2023年第8期2083-2107,共25页
The ongoing effort to create methods for detecting and quantifying fatigue damage is motivated by the high levels of uncertainty in present fatigue-life prediction approaches and the frequently catastrophic nature of ... The ongoing effort to create methods for detecting and quantifying fatigue damage is motivated by the high levels of uncertainty in present fatigue-life prediction approaches and the frequently catastrophic nature of fatigue failure.The fatigue life of high strength aluminum alloy 2090-T83 is predicted in this study using a variety of artificial intelligence and machine learning techniques for constant amplitude and negative stress ratios(R?1).Artificial neural networks(ANN),adaptive neuro-fuzzy inference systems(ANFIS),support-vector machines(SVM),a random forest model(RF),and an extreme-gradient tree-boosting model(XGB)are trained using numerical and experimental input data obtained from fatigue tests based on a relatively low number of stress measurements.In particular,the coefficients of the traditional force law formula are found using relevant numerical methods.It is shown that,in comparison to traditional approaches,the neural network and neuro-fuzzy models produce better results,with the neural network models trained using the boosting iterations technique providing the best performances.Building strong models from weak models,XGB helps to predict fatigue life by reducing model partiality and variation in supervised learning.Fuzzy neural models can be used to predict the fatigue life of alloys more accurately than neural networks and traditional methods. 展开更多
关键词 Fatigue life high strength aluminum alloy 2090-T83 NEURO-FUZZY tree boosting model neural networks adaptive neuro-fuzzy inference systems random forest support vector machines
下载PDF
EFFECTS OF IMPURITIES AND RARE EARTH ADDITION ON THE TOUGHENING LEVELS OF Al-Li BASED ALLOYS 2090 AND 1420
4
作者 L.Meng T.P.Tu +1 位作者 Y.Z.Yang M.S.Liu 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1998年第3期163-168,共6页
The effects of the impurities Fe, Si, Na, K and a rare earth addition, Ce, on the intrinsic and extrinsic toughening levels have been investigated for the Al-Li based alloys 2090 and 1420. 29K reduction in the toughen... The effects of the impurities Fe, Si, Na, K and a rare earth addition, Ce, on the intrinsic and extrinsic toughening levels have been investigated for the Al-Li based alloys 2090 and 1420. 29K reduction in the toughening level for the alloy 2090 with impurities 0.42% Fe+Si or 0.0132% Na+K i4 identified to be caused by the impurities.An improvement on the fracture toughness can be made by adding 0.05%-0.25% Ce to the alloy 2090. The reason behind this is that Ce microalloying can not only enhance both the intrinsic toughening level and the extrinsic toughening level but also suppress the embrittling behavior of the impurities. However, 0.06%-0.15% Ce microalloying fails to bring about any beneficial effect to the toughening level for the alloy 1420. 展开更多
关键词 al-li based alloy IMPURITY Ce addition TOUGHENING
下载PDF
Behavior of Growth and Coarsening of T_1(Al_2CuLi) Precipitates in Al-Li Alloys 2090 and 2090+Ce
5
作者 Zhilong Zhao, Lin Liu, Zheng Chen Dopartment of Mechanical Engineering, Northwestern Polytechnical University, Xi’an 710072, China 《Rare Metals》 SCIE EI CAS CSCD 2001年第3期174-177,共4页
The behavior of growth and coarsening of T-1(Al2CuLi) precipitates was comparatively studied by means of TEM technique in two Al-Li alloys 2090 and 2090+Ce (with cerium content less than 0.1% in mass fraction). Statis... The behavior of growth and coarsening of T-1(Al2CuLi) precipitates was comparatively studied by means of TEM technique in two Al-Li alloys 2090 and 2090+Ce (with cerium content less than 0.1% in mass fraction). Statistical analysis results show that T-1 precipitates in alloy 2090+Ce have smaller aspect ratio, which is connected with the more intersections between different T-1 variants in this alloy. It is also found that the variation of maximum length of T-1 precipitates with aging time can be obviously divided into two stages of growth and coarsening. The diffusion coefficients of solute atoms of Cu and Li are calculated via growth kinetics curves of T-1 precipitates. The results show that the diffusion of atom Cu plays a more important role in the formation of T-1 precipitates. 展开更多
关键词 al-li alloy T-1(Al2CuLi) precipitates growth and coarsening trace addition of cerium
下载PDF
Fatigue crack initiation and early propagation behavior of 2A97 Al-Li alloy 被引量:6
6
作者 钟警 钟申 +2 位作者 郑子樵 张海锋 罗先甫 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第2期303-309,共7页
The fatigue crack initiation and early propagation behavior of 2A97 Al-Li alloy was studied. The smooth specimens were fatigued at room temperature under constant maximum stress control when stress ratio (R) is 0.1 ... The fatigue crack initiation and early propagation behavior of 2A97 Al-Li alloy was studied. The smooth specimens were fatigued at room temperature under constant maximum stress control when stress ratio (R) is 0.1 and frequency (f) is 40 Hz. Microstructure observations were examined by optical microscopy, transmission electron microscopy, scanning electron microscopy and electron back scattered diffusion, in order to investigate the relationship between microstructure and fatigue crack initiation and early propagation behavior of 2A97 alloy. The results show that the fatigue cracks are predominantly initiated at inclusions and coarsen secondary phases on the surface of 2A97 alloy. The fatigue crack early propagation behavior of 2A97 alloy is predominantly influenced by the interactions between grain structure and dislocations or persistent slip bands (PSBs). When the misorientation of two neighbouring grains is close to the orientations of the favorable slip plane within these two grains, high-angle grain boundary severely hinders the PSBs passing through, and thus leads to crack bifurcation and deflection. 展开更多
关键词 2A97 al-li alloy fatigue crack initiation fatigue crack early propagation
下载PDF
Grain structure and microtexture evolution during superplastic deformation of 5A90 Al-Li alloy 被引量:4
7
作者 张盼 叶凌英 +3 位作者 张新明 顾刚 蒋海春 吴豫陇 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第7期2088-2093,共6页
The microstructural evolution of banded 5A90 A1-Li alloy during superplastic deformation at 475℃ with an initial strain rate of 8× 10^-4 S^-1 was studied using EBSD technique. The results showed that, before def... The microstructural evolution of banded 5A90 A1-Li alloy during superplastic deformation at 475℃ with an initial strain rate of 8× 10^-4 S^-1 was studied using EBSD technique. The results showed that, before deformation, the grain shape appeared to be banded, the most grain boundaries belonged to low-angle boundaries, and the initial sheet had a dominate of { 110}(112) brass texture. During deformation, there were grain growth, grain shape change, misorientation increasing and textural weakening. The fraction of high-angle boundaries increased rapidly once the flow stress reached the peak value. Corresponding deformation mechanism for various stages of deformation was suggested. Dislocation activity was the dominant mechanism in the first stage, then dynamic recrystallization occurred, and grain rotation was expected as an accommodation for grain boundary sliding (GBS). At large strains, GBS was the main mechanism. 展开更多
关键词 5A90 al-li alloy SUPERPLASTICITY MICROSTRUCTURE MICROTEXTURE
下载PDF
Hot deformation behavior and microstructure evolution of 1460 Al-Li alloy 被引量:2
8
作者 向胜 刘丹阳 +3 位作者 朱瑞华 李劲风 陈永来 张绪虎 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第12期3855-3864,共10页
The hot deformation behavior and microstructure evolution of 1460 Al-Li alloy were investigated by isothermal compression test conducted at various strain rates(10-3-10 s-1) and temperatures(573-773 K). The flow s... The hot deformation behavior and microstructure evolution of 1460 Al-Li alloy were investigated by isothermal compression test conducted at various strain rates(10-3-10 s-1) and temperatures(573-773 K). The flow stress curves were corrected by considering the friction at the platen/specimen interface and the temperature change due to the deformation heating. The effects of strain, strain rate and temperature on the deformation behavior were characterized by the Zener-Hollomon parameter in a hyperbolic-sine equation, and the constitutive equations were established according to the peak flow stress associated with dynamic recovery, dynamic recrystallization and the dissolution of T1 phases. In the entire strain rate and temperature range, the prediction capabilities of the developed constitutive equation are proved to be feasible and effective with a linear correlation coefficient and an average absolute relative error coefficient of 0.9909 and 6.72%, respectively. 展开更多
关键词 1460 al-li alloy friction correction temperature rise correction constitutive equation hot deformation behavior
下载PDF
Effect of thermo-mechanical treatment process on microstructure and mechanical properties of 2A97 Al-Li alloy 被引量:11
9
作者 高崇 栾阳 +1 位作者 于俊川 马岳 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第7期2196-2202,共7页
2A97 Al-Li alloy was processed by thermo-mechanical treatment at different pre-stretch deformations of 0, 3% and 6%. The microstrucatre observation results reveal that some δ' and T1 precipitates are found in a(Al... 2A97 Al-Li alloy was processed by thermo-mechanical treatment at different pre-stretch deformations of 0, 3% and 6%. The microstrucatre observation results reveal that some δ' and T1 precipitates are found in a(Al) matrix of 2A97 alloy processed by the heat treatment with no pre-stretch deformation. When the pre-stretch deformation is 3% and 6%, respectively, amounts of tiny T1 and a few of S' precipitates precipitates are observed in the microstructures of 2A97 alloy. The tensile test results show that the tensile properties of 2A97 alloys are improved via thermo-mechanical treatment. When the pre-stretch deformation is from 0, 3% to 6%, the ultimate tensile strength values of the 2A97 alloys increase gradually from 447.7, 516.5 to 534.3 MPa, and the elongations decrease from 17.6%, 12.8% to 10.2%, respectively. Moreover, with increasing pre-stretch deformation amount from 0 to 6%, the in-plane anisotropy value of 2A97 alloys becomes more obvious. 展开更多
关键词 2A97 al-li alloy thermo-mechanical treatment pre-stretch deformation microstructure mechanical properties
下载PDF
Strength and structure variation of 2195 Al-Li alloy caused by different deformation processes of hot extrusion and cold-rolling 被引量:10
10
作者 Yun-long MA Jin-feng LI +4 位作者 Run-zhe ZHANG Jian-guo TANG Cheng HUANG Hong-ying LI Zi-qiao ZHENG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2020年第4期835-849,共15页
2195 Al-Li alloy was deformed through extrusion followed by cold-rolling.The textures of the extruded plate and cold-rolled sheet after solutionization were investigated.The longitudinal strength and precipitates afte... 2195 Al-Li alloy was deformed through extrusion followed by cold-rolling.The textures of the extruded plate and cold-rolled sheet after solutionization were investigated.The longitudinal strength and precipitates after T8 aging were measured and observed,respectively.Compared to those in the sheet,T1(Al2 Cu Li)precipitates in the extruded plate after T8 aging are non-uniform,and their incubation time is shorter.The extruded plate after solutionization is not recrystallized and contains 55.28%deformation textures of Brass and S.In the cold-rolled sheet after solutionization,massive recrystallization occurs and S component disappears.Due to the higher fraction of Brass and S textures with higher Schmid factor and lower equivalent sliding system number,the extruded plate possesses an yield strength not higher or even lower,but a tensile strength higher,than the cold-rolled sheet after solutionization.In addition,during the aging after pre-stretch,these textures promote T1 precipitation on preferred sliding planes of cold-rolled sheet and cause its higher yield strength and tensile strength after T8 aging. 展开更多
关键词 al-li alloy COLD-ROLLING EXTRUSION TEXTURE PRECIPITATE STRENGTH
下载PDF
Through-thickness inhomogeneity of precipitate distribution and pitting corrosion behavior of Al-Li alloy thick plate 被引量:11
11
作者 Kuo ZHAO Jian-hua LIU +1 位作者 Mei YU Song-mei LI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2019年第9期1793-1802,共10页
The thorough-thickness inhomogeneity of precipitate distribution and pitting corrosion behavior of 95 mm-thick 2297 Al-Li alloy rolled plate was investigated using scanning electron microscopy, transmission electron m... The thorough-thickness inhomogeneity of precipitate distribution and pitting corrosion behavior of 95 mm-thick 2297 Al-Li alloy rolled plate was investigated using scanning electron microscopy, transmission electron microscopy and electrochemistry method. Precipitate distribution and pit size were statistically analyzed to obtain quantitative information and corresponding correlation. The population density and the size fraction of precipitate on different sections in the thick plate are ranked from high to low in the following order: quarter-section(QS) > surface section(SS) > mid-section(MS). After 300 min potentiostatic polarization, the number and the total volume of pits are ranked from high to low as QS>SS>MS, indicating a higher pitting susceptibility of the plate in QS with more precipitates. The through-thickness inhomogeneity of pitting corrosion in 2297 Al-Li alloy thick plate is mainly ascribed to inhomogeneous precipitate distribution. 展开更多
关键词 al-li alloy pitting corrosion PRECIPITATE electrochemical behavior
下载PDF
Microstructures evolution and mechanical properties disparity in 2070 Al-Li alloy with minor Sc addition 被引量:9
12
作者 Dan-yang LIU Jie-xia WANG Jin-feng LI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2018年第11期2152-2162,共11页
The microstructures and mechanical properties of Al-3.35Cu-1.2Li-0.4Mg-0.4Zn-0.3Mn-0.1Zr (mass fraction, %) alloywith Sc addition or free Sc were investigated through tensile test, SEM, EPMA and TEM. The addition of... The microstructures and mechanical properties of Al-3.35Cu-1.2Li-0.4Mg-0.4Zn-0.3Mn-0.1Zr (mass fraction, %) alloywith Sc addition or free Sc were investigated through tensile test, SEM, EPMA and TEM. The addition of 0.082% (mass fraction) Scelement leads to the formation of Cu-rich and Sc-contained nano-sized Al3(ScZr) particles and W phase particles. The Al3(ScZr)particles can inhibit recrystallization to a certain extent and impede recrystallized grain growth during solution treatment. It is foundthat W phase cannot dissolve in supersaturated solid solution during the solution heat treatment, and the Cu content in thesolutionized matrix is decreased, which causes a decrease in the fraction of Cu-contained strengthening precipitates with T1 (Al2CuLi)and θ' (Al2Cu) under T8 aging condition. Due to the formation of the W phases, the small Sc addition causes a little reduction in thestrength. 展开更多
关键词 al-li alloy Sc addition microstructure mechanical properties
下载PDF
Flow curve correction and processing map of 2050 Al-Li alloy 被引量:6
13
作者 Rui-hua ZHU Qing LIU +3 位作者 Jin-feng LI Yong-lai CHEN Xu-hu ZHANG Zi-qiao ZHENG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2018年第3期404-414,共11页
Hot compression tests of 2050 Al-Li alloy were performed in the deformation temperature range of 340-500°C and strain rate range of 0.001-10 s-1 to investigate the hot deformation behavior of the alloy.The effect... Hot compression tests of 2050 Al-Li alloy were performed in the deformation temperature range of 340-500°C and strain rate range of 0.001-10 s-1 to investigate the hot deformation behavior of the alloy.The effects of friction and temperature difference on flow stress were analyzed and the flow curves were corrected.Based on the dynamic material model,processing map at a strain of 0.5 was established.The grain structure of the compressed samples was observed using optical microscopy.The results show that friction and temperature variation during the hot compression have significant influences on flow stress.The optimum processing domains are in the temperature range from 370 to 430°C with the strain rate range from 0.01 to 0.001 s-1,and in the temperature range from 440 to 500°C with the strain rate range from 0.3 to 0.01 s-1;the flow instable region is located at high strain rates(3-10 s-1)in the entire temperature range.Dynamic recovery(DRV)and dynamic recrystallization(DRX)are the main deformation mechanisms of the 2050 alloy in the stable domains,whereas the alloy exhibits flow localization in the instable region. 展开更多
关键词 2050 al-li alloy processing map dynamic recovery dynamic recrystallization flow localization
下载PDF
Effect of Rare Earth Cerium on Yield Strength Anisotropy of Al-Li Alloy Sheet and Its Theoretical Prediction 被引量:5
14
作者 赵志龙 刘林 陈铮 《Journal of Rare Earths》 SCIE EI CAS CSCD 2004年第3期410-413,共4页
The variation of yield strength along rolling direction, transverse direction and 45° to transverse direction of 2090 Al-Li alloy and 2090+Ce alloy sheet containing rare earth cerium was comparatively investigate... The variation of yield strength along rolling direction, transverse direction and 45° to transverse direction of 2090 Al-Li alloy and 2090+Ce alloy sheet containing rare earth cerium was comparatively investigated. The difference of deformation texture in these two alloy sheets was analyzed by means of X-ray orientation distribution function (ODF). The results show that cerium has the effects of enhancing the Brass and S rolling texture components and reducing the recrystallized texture components of Cube and Goss. This is the reason that the anisotropic degree of yield strength in 2090+Ce sheet is higher than that of 2090 alloy sheet. The prediction of yield strength along various orientations in two alloy sheets was done based on Taylor/Bishop-Hill model, and the strengthening effect of grain boundary was evaluated using Hall-Petch relationship. A modified plastic inclusion model was proposed using the concept of grain-orientation factor and T1 phase orientation factor by fitting with tensile test results. 展开更多
关键词 metal materials al-li alloy deformation texture ANISOTROPY orientation factors rare earths
下载PDF
Effect of large strain cross rolling on microstructure and properties of Al-Li alloy plates with high magnesium content 被引量:4
15
作者 Cai-he FAN Dong-sheng ZHENG +3 位作者 Xi-hong CHEN Jian-jun YANG Yong LIU Hui-zhong LI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2019年第2期263-269,共7页
Transmission electron microscopy(TEM),electron backscattered diffraction imaging(EBSD)and X-ray diffractometry were used to analyze the microstructure and texture characteristics of Al-9.8Mg-1.5Li-0.4Mn alloy cross-ro... Transmission electron microscopy(TEM),electron backscattered diffraction imaging(EBSD)and X-ray diffractometry were used to analyze the microstructure and texture characteristics of Al-9.8Mg-1.5Li-0.4Mn alloy cross-rolled and extruded plates,and the tensile properties and deep drawing performance were measured.The results show that the occurrence of dynamic recrystallization was promoted,the grains were refined and the preferred orientation of the recrystallized grains was improved by large strain cross rolling.Compared with CBA and CCB rolling methods,CBB rolling method significantly reduced the orientation density of the typical Brass texture{110}?112?in the extruded plates.The orientation densities of Copper texture{112}?111?and Brass texture{110}?112?on theβorientation line in the CBB rolled plates were the lowest,and there were no typical texture features in the plates.Meanwhile,better deep drawing could be gained in the CBB rolled plates,and the mechanical properties of the 0°,45°and 90°directions were basically the same.The tensile strength,yield strength and elongation at room temperature for the CBB rolled plates were 617 MPa,523 MPa and over 20.1%,respectively.The deviation of the mechanical properties at different directions was less than 3%. 展开更多
关键词 cross rolling al-li alloy plate MICROSTRUCTURE ANISOTROPY texture feature
下载PDF
Effects of pre-rolling on mechanical properties and fatigue crack growth rate of 2195 Al-Li alloy 被引量:4
16
作者 CHEN Meng-xi LI Yi-bo +4 位作者 XIA Lin-yan HUANG Ming-hui WU Zhen-yu YANG Yi QU Zi-jing 《Journal of Central South University》 SCIE EI CAS CSCD 2022年第3期836-847,共12页
While pre-deformation is often conducted before aging treatment to increase the strength and microhardness of 2195 Al-Li alloy, it often increases the fatigue crack growth(FCG) rate and thus reduces the fatigue life o... While pre-deformation is often conducted before aging treatment to increase the strength and microhardness of 2195 Al-Li alloy, it often increases the fatigue crack growth(FCG) rate and thus reduces the fatigue life of the alloy.To determine the effects and causes of pre-deformation and heat treatment on the mechanical properties and FCG rate of2195 Al-Li alloy, and to provide a suitable calculation model for the FCG rate under different pre-deformation conditions, 2195 Al-Li alloy specimens with different degrees of pre-rolling(0, 3%, 6%, and 9%) were investigated. The experimental results indicate that with the increase of pre-rolling, the density of the T1phase and the uniformity of the S′distribution and the microhardness, tensile strength, and yield strength of the alloy increase and at the same time the FCG rate increases, and thus the fatigue life is reduced. It was also found that the normalized stress intensity factor of elastic modulus(E) can be applied to correlate the FCG rate of pre-rolled 2195 Al-Li alloy with constant C and K parameters. 展开更多
关键词 2195 al-li alloy pre-rolling OVER-AGING fatigue crack growth mechanical properties
下载PDF
Preparation and Corrosion Resistance of Anodic Oxidation Coatings on 2198 and 5A90 Al-Li Alloys 被引量:3
17
作者 WANG Henan LI Xinming +2 位作者 HE Linbo CUI Baolei LIU Chunzhong 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2019年第1期132-137,共6页
2198 and 5A90 Al-Li alloys were anodized with a constant DC potential in 18%H_2SO_4solution(Solu.A) and the mixture solution of 18%H_2SO_4+5%C_2H_2O_4(Solu.B) at room temperature. 12 and 11 V was optimized as the appl... 2198 and 5A90 Al-Li alloys were anodized with a constant DC potential in 18%H_2SO_4solution(Solu.A) and the mixture solution of 18%H_2SO_4+5%C_2H_2O_4(Solu.B) at room temperature. 12 and 11 V was optimized as the applied oxidation potential for 2198 and 5A90 alloys, respectively. Cross-sectional morphology, surface morphology and elements distribution of anodic oxidation coatings were observed by scanning electron microscope equipped with energy dispersive X-ray analysis(SEM/EDX). Corrosion resistance was tested by potentiodynamic polarization plot in 3.5%NaCl solution. The results showed that the thicknesses of coatings obtained at the selected potential in Solu.A and Solu.B were about 50 μm/110 μm for 2198 alloy and 80 μm/110 μm for 5A90 alloy. In both solutions, anodic oxidation coatings of 2198 alloy were primarily composed of Al oxides; those of 5A90 alloy were mainly consisted of Al oxides and a small amount of Mg oxides. The results of potentiodynamic polarization showed that anodic oxidation coatings of 2198 and 5A90 Al-Li alloys had better corrosion resistances than that of untreated alloys. 展开更多
关键词 al-li alloy the MIXTURE solution anodic OXIDATION coating corrosion resistance thickness
下载PDF
MICROSTRUCTURE AND MECHANICAL PROPERTIES OF 8090 Al-Li ALLOY 被引量:3
18
作者 LIU Yulin ZHANG Yun ZHAO Hong’en HU Zhuangqi SHI Changxu Institute of Metal Research,Academia Sinica,Shentang,China 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1992年第2期89-94,共6页
The change of mechanical properties of the 8090 Al-Li alloy influenced by aging is attributed to the change of δ′-phase particle size and the precipitation of S′-phase.The δ′-phase may easily precipitate and rapi... The change of mechanical properties of the 8090 Al-Li alloy influenced by aging is attributed to the change of δ′-phase particle size and the precipitation of S′-phase.The δ′-phase may easily precipitate and rapidly grow,but the S′-phase can only precipitate with a longer stage of incubation.The precipitation of S′-phase would be promoted by cold working prior to ag- ing.The co-precipitation of δ′- and S′-phase could improve the strength and plastieity of the alloy,for which aging at 190℃.for 20—30 h seems to be optimal.In addition,the precipitate free zone( PFZ)can form at high angle grain boundary and its width is over 200 nm in peak aging condition.But at sub-grain boundary,the formation of PFZ is difficult. 展开更多
关键词 al-li alloy aging MICROSTRUCTURE mechanical properties
下载PDF
Superplastic deformation behavior and mechanism of 1420 Al-Li alloy sheets with elongated grains 被引量:2
19
作者 张新明 郑大伟 +1 位作者 叶凌英 唐建国 《Journal of Central South University》 SCIE EI CAS 2010年第4期659-665,共7页
True stress-true strain curve,microstructure and texture information were obtained to investigate the superplastic deformation behavior of 1420 Al-Li alloy sheets with initial elongated grains.From the true stress-tru... True stress-true strain curve,microstructure and texture information were obtained to investigate the superplastic deformation behavior of 1420 Al-Li alloy sheets with initial elongated grains.From the true stress-true curve,the stress increases with the increase of strain to 0.15,then dramatically decreases with the increase of strain to 0.80,and finally keeps almost a horizontal line.Meanwhile,initial elongated grains are gradually changed into equiaxed grains and the initial strong Brass {0 1 1} <2 1 1> and S {1 2 3} <6 3 4> orientations are turned into nearly random orientation with increasing strain.All these results suggest that dislocation activity is the dominant mechanism during the first stage,then dynamic recrystallization occurs,and grain rotation is expected as an accommodation for grain boundary sliding(GBS).At larger strains,grain boundary migration(GBM) becomes necessary to accommodate GBS. 展开更多
关键词 1420 al-li alloy SUPERPLASTICITY MICROSTRUCTURE TEXTURE DISLOCATION
下载PDF
Formation mechanism of gradient-distributed particles and their effects on grain structure in 01420 Al-Li alloy 被引量:5
20
作者 张新明 叶凌英 +2 位作者 刘颖维 杜予晅 罗智辉 《Journal of Central South University of Technology》 EI 2008年第2期147-152,共6页
Fine-grained 01420 Al-Li alloy sheets were produced by thermo-mechanical processing based on the mechanism of particle stimulated nucleation of recrystallization.The thermo-mechanically processed sheets were observed ... Fine-grained 01420 Al-Li alloy sheets were produced by thermo-mechanical processing based on the mechanism of particle stimulated nucleation of recrystallization.The thermo-mechanically processed sheets were observed to contain layers of different microstructures along the thickness.The precipitate behavior of the second phase particles and their effects on the distribution of dislocations and layered recrystallized grain structure were analyzed by optical microscopy(OM),scanning electron microscopy(SEM),transmission electron microscopy(TEM) and X-ray diffractometry(XRD).The formation mechanism of the gradient particles was discussed.The results show that after aging,a gradient distribution of large particles along the thickness is observed,the particles in the surface layer(SL) are distributed homogeneously,whereas those in the center layer(CL) are mainly distributed parallel to the rolling direction,and the volume fraction of the particles in the SL is higher than that in the CL.Subsequent rolling in the presence of layer-distributed particles results in a corresponding homogeneous distribution of highly strained regions in the SL and a banded distribution of them in CL,which is the main reason for the formation of layered grain structure along the thickness in the sheets. 展开更多
关键词 01420 al-li alloy layered grain structure grain refinement thermo-mechanical processing particle stimulatednucleation(PSN)
下载PDF
上一页 1 2 6 下一页 到第
使用帮助 返回顶部