The microstructural evolution and corrosion behavior of Ni_(62)Nb_(33)Zr_(5)bulk metallic glasses(BMGs)after annealing treatment(AT)at different crystallization temperatures and cryogenic treatment(CT)at−100℃are expe...The microstructural evolution and corrosion behavior of Ni_(62)Nb_(33)Zr_(5)bulk metallic glasses(BMGs)after annealing treatment(AT)at different crystallization temperatures and cryogenic treatment(CT)at−100℃are experimen-tally investigated.Appropriate AT and CT can both improve the thermal stability and comprehensive corrosion resistance of as-cast BMG in 3.5 wt.%NaCl solution.The annealed and cryo-treated BMGs exhibit one more finite diffusion layer loop in the electrical equivalent circuit than the as-cast BMG,indicating the complexity of the corrosion behavior.Superior corrosion resistance is obtained in the cryo-treated BMG because the high degree of amorphization caused by CT reduces the structural inhomogeneity.Lower C_(d)and higher R_(d)values are obtained for the cryo-treated BMG,revealing the formation of a more stable passive film.Among the annealed BMGs,the fully crystallized sample exhibits a higher anti-corrosion performance owing to the existence of Nb-rich oxides in the crystallization products.The passive film is found to be composed mainly of Nb_(2)O_(5)and ZrO_(2),demonstrating that Nb and Zr are conducive to reacting with oxygen to form a passive film.Based on the goal of maintaining a fully amorphous phase,appropriate CT causing structural homogeneity of the BMG is a simple and effective means to improve the comprehensive corrosion resistance.展开更多
基金the National Natu-ral Science Foundation of China(No.51971102)Open Research Fund of Songshan Lake Materials Laboratory(No.2021SLABFK08)Sci-ence and Technology Program of University of Jinan(No.XKY2117).
文摘The microstructural evolution and corrosion behavior of Ni_(62)Nb_(33)Zr_(5)bulk metallic glasses(BMGs)after annealing treatment(AT)at different crystallization temperatures and cryogenic treatment(CT)at−100℃are experimen-tally investigated.Appropriate AT and CT can both improve the thermal stability and comprehensive corrosion resistance of as-cast BMG in 3.5 wt.%NaCl solution.The annealed and cryo-treated BMGs exhibit one more finite diffusion layer loop in the electrical equivalent circuit than the as-cast BMG,indicating the complexity of the corrosion behavior.Superior corrosion resistance is obtained in the cryo-treated BMG because the high degree of amorphization caused by CT reduces the structural inhomogeneity.Lower C_(d)and higher R_(d)values are obtained for the cryo-treated BMG,revealing the formation of a more stable passive film.Among the annealed BMGs,the fully crystallized sample exhibits a higher anti-corrosion performance owing to the existence of Nb-rich oxides in the crystallization products.The passive film is found to be composed mainly of Nb_(2)O_(5)and ZrO_(2),demonstrating that Nb and Zr are conducive to reacting with oxygen to form a passive film.Based on the goal of maintaining a fully amorphous phase,appropriate CT causing structural homogeneity of the BMG is a simple and effective means to improve the comprehensive corrosion resistance.
