Isotropic etching polishing(IEP)based on the merging of isotropic etch pits has been proposed as a generic metal finishing approach.In this work,the tuning of the etching isotropy of various metals,which is the key to...Isotropic etching polishing(IEP)based on the merging of isotropic etch pits has been proposed as a generic metal finishing approach.In this work,the tuning of the etching isotropy of various metals,which is the key to realizing the finishing effect of IEP,is studied by theoretical analysis and etching experiments.The isotropic etching of various metals can be realized through mass transfer polarization by adjusting the electrochemical parameters.The addition of sulfuric acid in the electrolyte is the most effective for tuning the isotropy of electrochemical etching.It can decrease the diffusion coefficient of metal ions,thereby increasing the resistance of mass transfer and transforming the electrochemical dissolution of metal into mass transfer polarization.In this study,the atomic and close-to-atomic scale surface finishing of various metals and alloys has been successfully achieved through isotropic etching.After etching at a current of 1.5 A for 3 min,the surface Sa roughness of TA2 is drastically reduced from 242 to 3.98 nm.After etching for 1 min at a current of 3 A,the surface Sa roughness of pure tungsten,NiTi,and CoCrNi decreases from 9.33,76.4,and 37.6 nm,respectively,to 1.16,2.01,and 2.51 nm,respectively.展开更多
Studying primary platinum minerals in chromite ores from an ultrabasic mass in Xizang in 1975, we discovered a bright-white isotropic metallic mineral with high hardness and high reflectance. The mineral was determine...Studying primary platinum minerals in chromite ores from an ultrabasic mass in Xizang in 1975, we discovered a bright-white isotropic metallic mineral with high hardness and high reflectance. The mineral was determined as pure chromium by the electron probe in 1976. In 1977, we also discovered some more pure chromium grains in展开更多
基金the National Natural Science Foundation of China(52035009,52005243)the Science and Technology Innovation Committee of Shenzhen Municipality(JCYJ20200109141003910,JCYJ20210324120402007,KQTD20170810110250357).
文摘Isotropic etching polishing(IEP)based on the merging of isotropic etch pits has been proposed as a generic metal finishing approach.In this work,the tuning of the etching isotropy of various metals,which is the key to realizing the finishing effect of IEP,is studied by theoretical analysis and etching experiments.The isotropic etching of various metals can be realized through mass transfer polarization by adjusting the electrochemical parameters.The addition of sulfuric acid in the electrolyte is the most effective for tuning the isotropy of electrochemical etching.It can decrease the diffusion coefficient of metal ions,thereby increasing the resistance of mass transfer and transforming the electrochemical dissolution of metal into mass transfer polarization.In this study,the atomic and close-to-atomic scale surface finishing of various metals and alloys has been successfully achieved through isotropic etching.After etching at a current of 1.5 A for 3 min,the surface Sa roughness of TA2 is drastically reduced from 242 to 3.98 nm.After etching for 1 min at a current of 3 A,the surface Sa roughness of pure tungsten,NiTi,and CoCrNi decreases from 9.33,76.4,and 37.6 nm,respectively,to 1.16,2.01,and 2.51 nm,respectively.
基金supported by the National Natural Science Foundation of China(Grant Nos.11932007,11772134,11972162,12072115,12072116)the Natural Science Foundation of Guangdong Province,China(Grant No.2023A1515012942)+1 种基金the Science and Technology Program of Guangzhou,China(Grant No.202102020678)the State Key Laboratory of Subtropical Building Science,South China University of Technology(Grant No.2022KA05).
文摘Studying primary platinum minerals in chromite ores from an ultrabasic mass in Xizang in 1975, we discovered a bright-white isotropic metallic mineral with high hardness and high reflectance. The mineral was determined as pure chromium by the electron probe in 1976. In 1977, we also discovered some more pure chromium grains in
