By performing the immersion,hydrogen evolution and electrochemical corrosion testing in a 0.1 mol/L NaCl solution,the corrosion performance of differently oriented samples cut from an as-rolled Mg-8wt.%Li alloy plate ...By performing the immersion,hydrogen evolution and electrochemical corrosion testing in a 0.1 mol/L NaCl solution,the corrosion performance of differently oriented samples cut from an as-rolled Mg-8wt.%Li alloy plate has been investigated and compared.It demonstrated that obvious anisotropy in corrosion resistance existed between the sample surfaces with different orientations.Among them,the corrosion rate of"ND"(the normal direction)samples with their surfaces perpendicular to the normal direction of the plate was the highest.The corrosion rate of"TD"(the transverse direction)samples with their surfaces perpendicular to the transverse direction of the plate took the second place.For the"RD"(the rolling direction)samples with their surfaces perpendicular to the rolling direction of the plate,they had the lowest corrosion rate.For all the samples,their corrosion performance and the pitting severity were mainly ascribed to the crystallographic texture ofα-Mg matrix phases because the formed surface films onβ-Li phases could provide good protection to the substrate.For the"ND"and"TD"samples,the exposed surfaces were composed of{0002},{1010}and{1120}planes ofα-Mg phases and subsequently resulted in their severe corrosion attack due to the corrosion couples between basal and prism planes.Since the crystallographic planes of exposedα-Mg phases on the surfaces of"RD"samples were mainly{1010}and{1120}prism planes,the pitting severity was the weakest.展开更多
Cone-shaped patterned sapphire substrate was prepared by inductively coupled plasma etching and GaN nucleation layer was grown on it by metal-organic chemical vapor deposition.A selective growth of GaN nucleation laye...Cone-shaped patterned sapphire substrate was prepared by inductively coupled plasma etching and GaN nucleation layer was grown on it by metal-organic chemical vapor deposition.A selective growth of GaN nucleation layer was found on the slope of the cone-shaped patterned sapphire substrat,and the distribution morphology of GaN had significantly changed after it was recrystallized.GaN selective growth and redistribution were analyzed by investigating the distribution of crystallographic planes on the cone surface and the atom array of specific planes at atom level.展开更多
基金financially supported by the National Key Research and Development Program of China under Grant(Nos.2017YFB0702001 and 2016YFB0301105)the Strategic New Industry Development Special Foundation of Shenzhen(No.JCYJ20170306141749970)+5 种基金the National Natural Science Foundation of China Projects under Grant(Nos.51871211 and 51701129)the Doctor Startup Fund of Natural Science Foundation Program of Liaoning Province(No.2019-BS-200)the funds of International Joint Laboratory for Light Alloys,Liaoning BaiQianWan Talents Programthe Domain Foundation of Equipment Advance Research of 13th Five-year Plan(No.61409220118)the Innovation Fund of Institute of Metal Research(IMR),Chinese Academy of Sciences(CAS)the National Basic Research Program of China(“973 Program”)(No.2013CB632205)。
文摘By performing the immersion,hydrogen evolution and electrochemical corrosion testing in a 0.1 mol/L NaCl solution,the corrosion performance of differently oriented samples cut from an as-rolled Mg-8wt.%Li alloy plate has been investigated and compared.It demonstrated that obvious anisotropy in corrosion resistance existed between the sample surfaces with different orientations.Among them,the corrosion rate of"ND"(the normal direction)samples with their surfaces perpendicular to the normal direction of the plate was the highest.The corrosion rate of"TD"(the transverse direction)samples with their surfaces perpendicular to the transverse direction of the plate took the second place.For the"RD"(the rolling direction)samples with their surfaces perpendicular to the rolling direction of the plate,they had the lowest corrosion rate.For all the samples,their corrosion performance and the pitting severity were mainly ascribed to the crystallographic texture ofα-Mg matrix phases because the formed surface films onβ-Li phases could provide good protection to the substrate.For the"ND"and"TD"samples,the exposed surfaces were composed of{0002},{1010}and{1120}planes ofα-Mg phases and subsequently resulted in their severe corrosion attack due to the corrosion couples between basal and prism planes.Since the crystallographic planes of exposedα-Mg phases on the surfaces of"RD"samples were mainly{1010}and{1120}prism planes,the pitting severity was the weakest.
基金Supported by the National Natural Science Foundation of China（Nos.61223005, 61376046）, the Program for New Century Excellent Talents in University of China（Nos.NCET-12-0236, NCET-13-0254）, the Science and Technology Developing Project of Jilin Province, China （No.20130204032GX） and the Opening Project of Science and Technology on Reliability Physics and Application Technology of Electronic Component Laboratory in the Fifth Electronics Research Institute of Ministry of Industry and Information Technology of China（No.ZHD201204）.
文摘Cone-shaped patterned sapphire substrate was prepared by inductively coupled plasma etching and GaN nucleation layer was grown on it by metal-organic chemical vapor deposition.A selective growth of GaN nucleation layer was found on the slope of the cone-shaped patterned sapphire substrat,and the distribution morphology of GaN had significantly changed after it was recrystallized.GaN selective growth and redistribution were analyzed by investigating the distribution of crystallographic planes on the cone surface and the atom array of specific planes at atom level.
