The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Guosheng Peng - One of the best experts on this subject based on the ideXlab platform.
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influence of dual rra temper on the Exfoliation Corrosion and electrochemical behavior of al zn mg cu alloy
Materials and Corrosion-werkstoffe Und Korrosion, 2013Co-Authors: Guosheng Peng, Songyi Chen, Kanghua Chen, H C FangAbstract:Influence of dual-retrogression and reaging (dual-RRA) temper on the Exfoliation Corrosion (EC) and electrochemical behavior of Al–Zn–Mg–Cu alloy has been investigated by means of transmission electron microscope, energy dispersive X-ray spectroscopy, tensile test, polarization curve, and EIS. Dual-RRA temper not only kept the strength similar to retrogression and reaging temper, but also improved EC resistance compared to T76 temper, being attributed to coarser and sparser grain boundary precipitates as well as higher Cu and lower Zn content. Obtained polarization curves and EIS are in good agreement with EC rating sequence.
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influence of dual retrogression and re aging temper on microstructure strength and Exfoliation Corrosion behavior of al zn mg cu alloy
Transactions of Nonferrous Metals Society of China, 2012Co-Authors: Guosheng Peng, Songyi Chen, Kanghua Chen, Huachan FangAbstract:Abstract Influence of dual retrogression and re-aging (dual-RRA) temper on microstructure, strength and Exfoliation Corrosion (EC) behavior of Al–Zn–Mg–Cu alloy was investigated by hardness measurements, tensile properties tests, Exfoliation Corrosion tests, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) observation combined energy dispersive X-ray detector (EDX) analysis. Dual-RRA temper maintains the matrix precipitates (MPs) similar to RRA temper, meanwhile obtains∼coarser and sparser grain boundary precipitates (GBPs) as well as higher∼Cu and lower Zn content compared with T76 temper. Therefore, dual-RRA temper not only keeps strength equivalent to the RRA temper but also obtains higher EC resistance than T76 temper.
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effect of heat treatment on strength Exfoliation Corrosion and electrochemical behavior of 7085 aluminum alloy
Materials & Design, 2012Co-Authors: Songyi Chen, Kanghua Chen, Guosheng Peng, Pengxuan DongAbstract:Abstract The influence of heat treatment on strength, Exfoliation Corrosion and electrochemical behavior of 7085 aluminum alloy has been investigated by tensile testing, Exfoliation Corrosion testing, polarization curve and electrochemical impedance spectroscopy (EIS) combined with transmission electron microscope (TEM). The results show that retrogression and reaging (RRA) improved Exfoliation Corrosion resistance without sacrificing the strength compared to T6 temper. Dual-retrogression and reaging (DRRA) improved Exfoliation Corrosion resistance equivalent to T74 temper and maintained the strength similar to retrogression and reaging. The high-temperature and the subsequent low-temperature aging (HLA) decreased the strength and Corrosion resistance compared to the T6 temper. The trends of Corrosion resistance are further confirmed by polarization curve experiment and EIS test. The effect of heat treatment on strength and Corrosion resistance is explained by the role of matrix precipitates and grain boundary precipitates, respectively.
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effect of cr yb and zr additions on localized Corrosion of al zn mg cu alloy
Corrosion Science, 2009Co-Authors: H C Fang, K H Chen, Xuehai Chen, H Chao, Guosheng PengAbstract:Abstract The effect of Cr, Yb and Zr additions on localized Corrosion of Al–Zn–Mg–Cu alloy has been investigated. Additions of Cr, Yb and Zr to Al–Zn–Mg–Cu alloy stabilized the deformation-recovery microstructure with low angle grain boundaries on which grain boundary precipitates distributed discretely. The Exfoliation and stress Corrosion cracking of Al–Zn–Mg–Cu alloys propagated along the high angle recrystallized grain boundaries. The unrecrystallized Al–Zn–Mg–Cu–Zr–Cr–Yb alloy exhibited higher resistance to stress Corrosion cracking and Exfoliation Corrosion, compared to the partial recrystallized Al–Zn–Mg–Cu–Zr alloy with high angle grain boundaries.
Zhimin Yin - One of the best experts on this subject based on the ideXlab platform.
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synergetic effects of sc and zr microalloying and heat treatment on mechanical properties and Exfoliation Corrosion behavior of al mg mn alloys
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2016Co-Authors: Yongyi Peng, Ying Deng, Hua Zhou, Zhimin YinAbstract:Abstract Mechanical properties, Exfoliation Corrosion behavior and microstructure of Al-5.98Mg-0.47Mn and Al-6.01Mg-0.45Mn-0.25Sc-0.10Zr (wt%) alloy sheets under various homogenizing and annealing processes were investigated comparatively by tensile tests, electrochemical measurements, X-ray diffraction technique and microscopy methods. The as-cast alloys mainly consist of Fe and Mn enriched impurity phases, Mg and Mn enriched non-equilibrium aluminides and Mg 3 Al 2 phases. During homogenization treatment, solvable intermetallics firstly precipitate and then dissolve into matrix. The optimized homogenization processes for removing micro-segregation and obtaining maximum precipitation strengthening of secondary Al 3 (Sc, Zr) particles are 440 °C×8 h and 300 °C×8 h, respectively. Sc and Zr additions can make the yield strength of Al-Mg-Mn alloy increase by 21 MPa (6.9%), 120 MPa (61.2%) and 127 MPa (68.3%), when annealed at 270 °C, 300 °C and 330 °C, respectively, indicating that Orowan precipitation strengthening caused by secondary Al 3 (Sc, Zr) nano-particles is much greater than grain boundary strengthening from primary Al 3 (Sc, Zr) micro-particles. Increasing homogenization and annealing degrees and adding Sc and Zr all can decrease Corrosion current density and improve Exfoliation Corrosion resistance. The Exfoliation Corrosion behavior is dominant by anodic dissolution occurring at the interface between intermetallics and ɑ(Al) matrix. After homogenizing at 440 °C for 8 h and annealing at 300 °C for 1 h, yield strength, ultimate strength, elongation to failure and Exfoliation Corrosion rank are 196 MPa, 360 MPa, 20.2% and PA (slight pitting Corrosion) in Al-Mg-Mn alloy, and reach to 316 MPa, 440 MPa, 17.0% and PA in Al-Mg-Mn-Sc-Zr alloy, respectively, revealing that high strength, high ductility and admirable Corrosion resistance of Al-Mg-Mn alloys can be achieved by the synergetic effects of Sc and Zr microalloying and heat treatment.
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Corrosion behaviour and mechanism of new aerospace al zn mg alloy friction stir welded joints and the effects of secondary al3scxzr1 x nanoparticles
Corrosion Science, 2015Co-Authors: Ying Deng, Qinglin Pan, Jidong Yang, Bing Peng, Xiaowu Cao, Yulu Duan, Yingjun Wang, Zhimin YinAbstract:Abstract Corrosion behaviour, residual stress, intermetallics and microstructure of friction stir welded aerospace Al–Zn–Mg and Al–Zn–Mg–0.10Sc–0.10Zr (wt.%) alloys were investigated comparatively and in detail. The thermo-mechanically affected zones adjacent to weld nugget are most susceptible to Corrosion in two weld joints. In addition to the enrichment of coarse Si and Fe intermetallics, wide precipitate free zones (in Al–Zn–Mg weld joint) and high tensile residual stress are the key factors. Secondary Al3ScxZr1−x nanoparticles can effectively improve stress Corrosion cracking resistance and decrease Exfoliation Corrosion rates of Al–Zn–Mg weld joints by restraining the formation of precipitate free zones and refining grains.
Lsolda Costa - One of the best experts on this subject based on the ideXlab platform.
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Exfoliation Corrosion susceptibility in the zones of friction stir welded aa2098 t351
Journal of materials research and technology, 2019Co-Authors: Mariana X Milagre, Uyime Donatus, Caruline De Souza Carvalho Machado, Joao Victor De Sousa Araujo, Raphael Oliveira Ferreira, Rejane Maria Pereira Da Silva, Renato Altobelli Antunes, Lsolda CostaAbstract:Abstract In the present study, the Exfoliation susceptibility of the weld zones in friction stir welded AA2098-T351 was compared with that of the base metal (BM) according to ASTM G34 standard practice. Friction stir welding (FSW) had a significant effect on the microstructure of the Al alloy tested and the susceptibility to Exfoliation was strongly affected by the microstructure. Different features of Corrosion attack and Exfoliation susceptibility were observed when the zones affected by FSW were tested isolated or coupled. Also, the near-surface deformed layer had an important effect on the Al alloy susceptibility to Exfoliation. These are the main findings of this work. The Corrosion features were correlated with the microstructural modifications related to the welding process and with the electrochemical response. The T1 phase morphology, distribution and size were critical for Exfoliation susceptibility. The stir zone (SZ) was the zone most resistant to Exfoliation. However, resistance to Exfoliation varied with the temperatures reached in the heat affected zones (HAZs). The HAZ exposed to the lowest temperatures during welding, HAZ (LT), was the most susceptible to Exfoliation, whereas the HAZ exposed to the highest temperatures, HAZ (HT), presented high resistance to Exfoliation, similarly to the SZ. The ASTM-G34 practice was an effective and useful method in identifying the different Exfoliation resistances of the BM and the various zones affected by FSW. The results of this practice were supported by electrochemical impedance spectroscopy (EIS) tests.
Qinglin Pan - One of the best experts on this subject based on the ideXlab platform.
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Corrosion behaviour and mechanism of new aerospace al zn mg alloy friction stir welded joints and the effects of secondary al3scxzr1 x nanoparticles
Corrosion Science, 2015Co-Authors: Ying Deng, Qinglin Pan, Jidong Yang, Bing Peng, Xiaowu Cao, Yulu Duan, Yingjun Wang, Zhimin YinAbstract:Abstract Corrosion behaviour, residual stress, intermetallics and microstructure of friction stir welded aerospace Al–Zn–Mg and Al–Zn–Mg–0.10Sc–0.10Zr (wt.%) alloys were investigated comparatively and in detail. The thermo-mechanically affected zones adjacent to weld nugget are most susceptible to Corrosion in two weld joints. In addition to the enrichment of coarse Si and Fe intermetallics, wide precipitate free zones (in Al–Zn–Mg weld joint) and high tensile residual stress are the key factors. Secondary Al3ScxZr1−x nanoparticles can effectively improve stress Corrosion cracking resistance and decrease Exfoliation Corrosion rates of Al–Zn–Mg weld joints by restraining the formation of precipitate free zones and refining grains.
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research on intercrystalline Corrosion Exfoliation Corrosion and stress Corrosion cracking of al zn mg sc zr alloy
Materials and Corrosion-werkstoffe Und Korrosion, 2013Co-Authors: Qinglin Pan, Zhiye ZhangAbstract:The intercrystalline Corrosion, Exfoliation Corrosion (EXCO), and stress Corrosion cracking (SCC) of Al–Zn–Mg–Sc–Zr alloy were investigated by means of constant temperature immersion Corrosion method, optical microscopy, transmission electron microscopy (TEM), and electrochemical impedance spectroscopy (EIS). The results show that intercrystalline Corrosion, and EXCO susceptibility of Al–Zn–Mg–Sc–Zr alloy decrease gradually with increasing of aging time. Corrosion susceptibility order from low to high is as follows: OA > PA > UA > NA. The SCC susceptibility index of PA temper is more than OA temper at the same strain rate. According to TEM observation, with aging time prolonging, a part of η′ phases transform to η equilibrium phases, which become coarse gradually. The distribution discontinuity of the grain boundary precipitates increases. In addition, for Al–Zn–Mg–Sc–Zr alloy without EXCO, the EIS is comprised by a capacitive impedance arc at high frequency and an inductive impedance arc at low frequency. Once EXCO occurs, the EIS is composed of two capacitive impedance arcs at high frequency and at low frequency, respectively.
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Exfoliation Corrosion of al zn mg cu zr alloy containing sc examined by electrochemical impedance spectroscopy
Materials and Corrosion-werkstoffe Und Korrosion, 2012Co-Authors: Yanping Xiao, Qinglin Pan, Xianling LiuAbstract:The Exfoliation Corrosion behavior of an Al–Zn–Mg–Cu–Zr alloy containing Sc artificially aged at 120 °C for 24 h is studied by macroscopic observation techniques and electrochemical impedance spectroscopy (EIS) measurements. After 48 h immersion, the blisters start bursting and delamination initiates, along with the appearance of two time constants in the impedance diagrams. According to the simulation by equivalent circuit, the Corrosion rate decreases sharply and then reaches a steady state, which is due to the change of the solution pH and oxide layer thickness, as well as the accumulation of Corrosion products.
H C Fang - One of the best experts on this subject based on the ideXlab platform.
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influence of dual rra temper on the Exfoliation Corrosion and electrochemical behavior of al zn mg cu alloy
Materials and Corrosion-werkstoffe Und Korrosion, 2013Co-Authors: Guosheng Peng, Songyi Chen, Kanghua Chen, H C FangAbstract:Influence of dual-retrogression and reaging (dual-RRA) temper on the Exfoliation Corrosion (EC) and electrochemical behavior of Al–Zn–Mg–Cu alloy has been investigated by means of transmission electron microscope, energy dispersive X-ray spectroscopy, tensile test, polarization curve, and EIS. Dual-RRA temper not only kept the strength similar to retrogression and reaging temper, but also improved EC resistance compared to T76 temper, being attributed to coarser and sparser grain boundary precipitates as well as higher Cu and lower Zn content. Obtained polarization curves and EIS are in good agreement with EC rating sequence.
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effect of cr yb and zr additions on localized Corrosion of al zn mg cu alloy
Corrosion Science, 2009Co-Authors: H C Fang, K H Chen, Xuehai Chen, H Chao, Guosheng PengAbstract:Abstract The effect of Cr, Yb and Zr additions on localized Corrosion of Al–Zn–Mg–Cu alloy has been investigated. Additions of Cr, Yb and Zr to Al–Zn–Mg–Cu alloy stabilized the deformation-recovery microstructure with low angle grain boundaries on which grain boundary precipitates distributed discretely. The Exfoliation and stress Corrosion cracking of Al–Zn–Mg–Cu alloys propagated along the high angle recrystallized grain boundaries. The unrecrystallized Al–Zn–Mg–Cu–Zr–Cr–Yb alloy exhibited higher resistance to stress Corrosion cracking and Exfoliation Corrosion, compared to the partial recrystallized Al–Zn–Mg–Cu–Zr alloy with high angle grain boundaries.