Mg Al-layered double hydroxides（LDH） coatings were fabricated by the in-situ hydrothermal treatment method on the AA5005 aluminum alloy.The characteristics of the coatings were investigated by XRD,FT-IR,SEM and EDS....Mg Al-layered double hydroxides（LDH） coatings were fabricated by the in-situ hydrothermal treatment method on the AA5005 aluminum alloy.The characteristics of the coatings were investigated by XRD,FT-IR,SEM and EDS.The effect of the p H value of the solution on the formation of the LDH coatings was studied.The optimum p H value of the solution was 10.0.The corrosion resistance of the LDH coatings was studied using potentiodynamic polarization tests and electrochemical impedance spectrum（EIS）.The results demonstrate that the LDH coatings,characterized by platelets vertically to the substrate surface possess excellent corrosion resistance.The influence of the hydrothermal crystallization time on the corrosion resistance was evaluated.Prolonging the crystallization time can increase the corrosion resistance of the obtained LDH coatings.The anticorrosion mechanism of the LDH coatings was discussed.展开更多
In this paper,the effect of cathodic polarization on corrosion behavior of AA7003 under three kinds of aging treatments(including peak aging(PA),double peak aging(DPA)and regression re-aging(RRA))was studied in 3.5 wt...In this paper,the effect of cathodic polarization on corrosion behavior of AA7003 under three kinds of aging treatments(including peak aging(PA),double peak aging(DPA)and regression re-aging(RRA))was studied in 3.5 wt%sodium chloride solution through slow strain rate testing(SSRT)and electrochemical testing.X-ray diffraction(XRD)and scanning electron microscopy(SEM)methods were also applied to investigating corrosion behavior and fracture morphology.The results showed that under open circuit,stress corrosion cracking(SCC)of AA7003 might by classified as anodic dissolution.In this case,the extent of SCC susceptibility(ISCC)of AA7003 alloy with different aging treatments was as follows:ISCC(PA)>ISCC(DPA)>ISCC(RRA).On the other hand,stress corrosion cracking(SCC)of AA7003 under cathodic polarization might be classified as hydrogen embrittlement(HE)which had been proved in this paper by presence of AlH3 diffraction peak in XRD patterns.In this case,for AA7003 with any of the three aging treatments,hydrogen embrittlement susceptibility(IHE)increases with negatively shifting of cathodic polarization.展开更多
In this paper, a novel and reliable structure of the side passivated emitter and the rear locallydiffused（PERL） silicon light emitting diodes （LEDs） is proposed. The inverted pyramids surface, the important interf...In this paper, a novel and reliable structure of the side passivated emitter and the rear locallydiffused（PERL） silicon light emitting diodes （LEDs） is proposed. The inverted pyramids surface, the important interface in this structure, is given according to the experiment. The results show that the inverted pyramids surface has a low refection about 8%, in the anisotropic etching 70 ℃, 5% TMAH concentration, corrosion time of 90 min or 30 rain. Low refection means high light emitting rate. Most of the structure and manufacturing process can be compatible with planar CMOS technology, which makes the silicon LED greater potential for development in the future.展开更多
The microstructure of welded joint is surveyed and the mechanical properties of X65 pipeline steel are studied in this paper, which provides experimental basis of performance effect on stress corrosion. H 2S stress co...The microstructure of welded joint is surveyed and the mechanical properties of X65 pipeline steel are studied in this paper, which provides experimental basis of performance effect on stress corrosion. H 2S stress corrosion cracking (SCC) tests on the steel are carried out in the environment based on NACE TM- 01-77 solution. The threshold stress intensity factor and crack propagation velocity for base metal and HAZ are obtained. The susceptibility of welded joint for X65 pipeline steel to H 2S stress corrosion cracking is investigated. The programming package ANSYS of finite element model (FEM) is used to perform the three-dimensional elastic-plastic finite element analysis of WOL specimens. Stress field and concentration of hydrogen distribution property of the crack tip are obtained.展开更多
基金Project(20133718120003)supported by the Doctoral Program Foundation of State Education Ministry,ChinaProject(BS2013CL009)supported by the Scientific Research Foundation of Shandong for Outstanding Young Scientist,China+1 种基金Projects(13-1-4-217-jch,13-1-4-188-jch)supported by the Applied Basic Research Foundation of Qingdao,ChinaProject(2014TDJH104)supported by the SDUST Research Fund,China
文摘Mg Al-layered double hydroxides（LDH） coatings were fabricated by the in-situ hydrothermal treatment method on the AA5005 aluminum alloy.The characteristics of the coatings were investigated by XRD,FT-IR,SEM and EDS.The effect of the p H value of the solution on the formation of the LDH coatings was studied.The optimum p H value of the solution was 10.0.The corrosion resistance of the LDH coatings was studied using potentiodynamic polarization tests and electrochemical impedance spectrum（EIS）.The results demonstrate that the LDH coatings,characterized by platelets vertically to the substrate surface possess excellent corrosion resistance.The influence of the hydrothermal crystallization time on the corrosion resistance was evaluated.Prolonging the crystallization time can increase the corrosion resistance of the obtained LDH coatings.The anticorrosion mechanism of the LDH coatings was discussed.
基金Projects(51371039,51871031)supported by the National Natural Science Foundation of ChinaProject supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),China
文摘In this paper,the effect of cathodic polarization on corrosion behavior of AA7003 under three kinds of aging treatments(including peak aging(PA),double peak aging(DPA)and regression re-aging(RRA))was studied in 3.5 wt%sodium chloride solution through slow strain rate testing(SSRT)and electrochemical testing.X-ray diffraction(XRD)and scanning electron microscopy(SEM)methods were also applied to investigating corrosion behavior and fracture morphology.The results showed that under open circuit,stress corrosion cracking(SCC)of AA7003 might by classified as anodic dissolution.In this case,the extent of SCC susceptibility(ISCC)of AA7003 alloy with different aging treatments was as follows:ISCC(PA)>ISCC(DPA)>ISCC(RRA).On the other hand,stress corrosion cracking(SCC)of AA7003 under cathodic polarization might be classified as hydrogen embrittlement(HE)which had been proved in this paper by presence of AlH3 diffraction peak in XRD patterns.In this case,for AA7003 with any of the three aging treatments,hydrogen embrittlement susceptibility(IHE)increases with negatively shifting of cathodic polarization.
文摘In this paper, a novel and reliable structure of the side passivated emitter and the rear locallydiffused（PERL） silicon light emitting diodes （LEDs） is proposed. The inverted pyramids surface, the important interface in this structure, is given according to the experiment. The results show that the inverted pyramids surface has a low refection about 8%, in the anisotropic etching 70 ℃, 5% TMAH concentration, corrosion time of 90 min or 30 rain. Low refection means high light emitting rate. Most of the structure and manufacturing process can be compatible with planar CMOS technology, which makes the silicon LED greater potential for development in the future.
文摘The microstructure of welded joint is surveyed and the mechanical properties of X65 pipeline steel are studied in this paper, which provides experimental basis of performance effect on stress corrosion. H 2S stress corrosion cracking (SCC) tests on the steel are carried out in the environment based on NACE TM- 01-77 solution. The threshold stress intensity factor and crack propagation velocity for base metal and HAZ are obtained. The susceptibility of welded joint for X65 pipeline steel to H 2S stress corrosion cracking is investigated. The programming package ANSYS of finite element model (FEM) is used to perform the three-dimensional elastic-plastic finite element analysis of WOL specimens. Stress field and concentration of hydrogen distribution property of the crack tip are obtained.
