Question 1:what do you think are the most impressive features of ChatGPT as a language model?Answer:Well,ChatGPT has several impressive features.Firstly,its ability to generate contextually relevant and coherent respo...Question 1:what do you think are the most impressive features of ChatGPT as a language model?Answer:Well,ChatGPT has several impressive features.Firstly,its ability to generate contextually relevant and coherent responses to natural language prompts is truly remarkable.This is achieved through the model's architecture,which includes multiple layers of artificial neural networks,and the vast amount of text data it has been trained on.The model can generate responses that are not only grammatically correct but also contextually appropriate and engaging,making it a powerful tool for natural language processing.展开更多
Investigation about the corrosion behavior of Ti alloys in different ambient environment is of great significance for their practical application.Herein,we systematically investigate the corrosion behavior of a newfou...Investigation about the corrosion behavior of Ti alloys in different ambient environment is of great significance for their practical application.Herein,we systematically investigate the corrosion behavior of a newfound Ti-6 Al-3 Nb-2 Zr-1 Mo(Ti80)alloy in hydrochloric acid(HCl)ranging from 1.37 to 7 M,and temperature ranging from 25 to 55℃,by means of electrochemical measurements,static immersion tests and surface analysis.Results manifest that increasing either HCl concentration or temperature can accelerate the corrosion of Ti80 alloy via promoting the breakdown of native protective oxide film and then further facilitating the active dissolution of Ti80 matrix.According to potentiodynamic polarization curves,Ti80 alloy displays a spontaneous passive behavior in 1.37 M HCl at 25℃,compared to a typical active-passive behavior under the other conditions.As indicated by cathodic Tafel slope,the rate determining step for cathodic hydrogen evolution reaction is likely the discharge reaction step.The apparent activation energies obtained from corrosion current density and maximum anodic current density for Ti80 alloy in 5 M HCl solution are 62.4 and 55.6 kJ mol-1,respectively,which signifies that the rate determining step in the corrosion process of Ti80 alloy is mainly determined by surface-chemical reaction rather than diffusion.Besides,the electrochemical impedance spectroscopy tests demonstrate that a stable and compact oxide film exists in 1.37 M HCl at 25℃,whereas a porous corrosion product film forms under the other conditions.Overall,the critical HCl concentration at which Ti80 alloy can maintain passivation at 25℃can be determined as a value between 1.37 and 3 M.Furthermore,the corroded surface morphology characterization reveals that equiaxedαphase is more susceptible to corrosion compared to intergranularβphase due to a lower content of Nb,Mo,and Zr in the former.展开更多
Corrosion resistance of titanium(Ti)alloys is closely connected with their microstructure which can be adjusted and controlled via different annealing schemes.Herein,we systematically investigate the specific effects ...Corrosion resistance of titanium(Ti)alloys is closely connected with their microstructure which can be adjusted and controlled via different annealing schemes.Herein,we systematically investigate the specific effects of annealing on the corrosion performance of Ti-6 Al-3 Nb-2 Zr-1 Mo(Ti80)alloy in 3.5 wt.%NaCl and 5 M HCl solutions,respectively,based on open circuit potential(OCP),potentiodynamic polarization,electrochemical impedance spectroscopy(EIS),static immersion tests and surface analysis.Results indicate that increasing annealing tempe rature endows Ti80 alloy with a higher volume fraction ofβphase and finerαphase,which in turn improves its corrosion resistance.Surface characterization demonstrates thatβphase is more resistant to corrosion thanαphase owing to a higher content of Nb,Mo,and Zr in the former;additionally,the decreased thickness of a phase alleviates segregation of elements to further restrain the micro-galvanic couple effects betweenαandβphases.Meanwhile,the influential mechanisms of environmental conditions on corrosion of Ti80 alloy are discussed in detail.As the formation of a highly compact and stable oxide film on surface,annealed Ti80 alloys exhibit a low corrosion current density(10^(-6)A/cm^(2))and high polarization impedance(10^(6)Ω·cm^(2))in 3.5 wt.%NaCl solution.However,they suffer severe corrosion in 5 M HCl solution,resulting from the breakdown of native oxide films(the conversion of TiO_(2)to aqueous Ti^(3+)),active dissolution of substrate Ti to aqueous Ti^(3+)and existence of micro-galvanic couple effects.Those findings could provide new insights to designing Ti alloys with high-corrosion resistance through microstructural optimization.展开更多
文摘Question 1:what do you think are the most impressive features of ChatGPT as a language model?Answer:Well,ChatGPT has several impressive features.Firstly,its ability to generate contextually relevant and coherent responses to natural language prompts is truly remarkable.This is achieved through the model's architecture,which includes multiple layers of artificial neural networks,and the vast amount of text data it has been trained on.The model can generate responses that are not only grammatically correct but also contextually appropriate and engaging,making it a powerful tool for natural language processing.
基金the National Key Research and Development Program of China(No.2016YFB0301201)the Yunnan Rare Metal Materials Genetic Engineering Project(No.2018ZE013)the National Natural Science Foundation of China(Nos.51425402 and 51671073)。
文摘Investigation about the corrosion behavior of Ti alloys in different ambient environment is of great significance for their practical application.Herein,we systematically investigate the corrosion behavior of a newfound Ti-6 Al-3 Nb-2 Zr-1 Mo(Ti80)alloy in hydrochloric acid(HCl)ranging from 1.37 to 7 M,and temperature ranging from 25 to 55℃,by means of electrochemical measurements,static immersion tests and surface analysis.Results manifest that increasing either HCl concentration or temperature can accelerate the corrosion of Ti80 alloy via promoting the breakdown of native protective oxide film and then further facilitating the active dissolution of Ti80 matrix.According to potentiodynamic polarization curves,Ti80 alloy displays a spontaneous passive behavior in 1.37 M HCl at 25℃,compared to a typical active-passive behavior under the other conditions.As indicated by cathodic Tafel slope,the rate determining step for cathodic hydrogen evolution reaction is likely the discharge reaction step.The apparent activation energies obtained from corrosion current density and maximum anodic current density for Ti80 alloy in 5 M HCl solution are 62.4 and 55.6 kJ mol-1,respectively,which signifies that the rate determining step in the corrosion process of Ti80 alloy is mainly determined by surface-chemical reaction rather than diffusion.Besides,the electrochemical impedance spectroscopy tests demonstrate that a stable and compact oxide film exists in 1.37 M HCl at 25℃,whereas a porous corrosion product film forms under the other conditions.Overall,the critical HCl concentration at which Ti80 alloy can maintain passivation at 25℃can be determined as a value between 1.37 and 3 M.Furthermore,the corroded surface morphology characterization reveals that equiaxedαphase is more susceptible to corrosion compared to intergranularβphase due to a lower content of Nb,Mo,and Zr in the former.
基金supported by the National Key Research and Development Program of China(2016YFB0301201)the Yunnan Rare Metal Materials Genetic Engineering Project(2018ZE013)the National Natural Science Foundation of China(51425402 and 51671073)。
文摘Corrosion resistance of titanium(Ti)alloys is closely connected with their microstructure which can be adjusted and controlled via different annealing schemes.Herein,we systematically investigate the specific effects of annealing on the corrosion performance of Ti-6 Al-3 Nb-2 Zr-1 Mo(Ti80)alloy in 3.5 wt.%NaCl and 5 M HCl solutions,respectively,based on open circuit potential(OCP),potentiodynamic polarization,electrochemical impedance spectroscopy(EIS),static immersion tests and surface analysis.Results indicate that increasing annealing tempe rature endows Ti80 alloy with a higher volume fraction ofβphase and finerαphase,which in turn improves its corrosion resistance.Surface characterization demonstrates thatβphase is more resistant to corrosion thanαphase owing to a higher content of Nb,Mo,and Zr in the former;additionally,the decreased thickness of a phase alleviates segregation of elements to further restrain the micro-galvanic couple effects betweenαandβphases.Meanwhile,the influential mechanisms of environmental conditions on corrosion of Ti80 alloy are discussed in detail.As the formation of a highly compact and stable oxide film on surface,annealed Ti80 alloys exhibit a low corrosion current density(10^(-6)A/cm^(2))and high polarization impedance(10^(6)Ω·cm^(2))in 3.5 wt.%NaCl solution.However,they suffer severe corrosion in 5 M HCl solution,resulting from the breakdown of native oxide films(the conversion of TiO_(2)to aqueous Ti^(3+)),active dissolution of substrate Ti to aqueous Ti^(3+)and existence of micro-galvanic couple effects.Those findings could provide new insights to designing Ti alloys with high-corrosion resistance through microstructural optimization.