摘要
A 304 stainless steel with the addition of 0.27 wt% Ag was found to exhibit excellent antibacterial properties. Based on Thermo-Calc calculation, a special heat treatment was introduced to obtain Ag precipitate in this steel. Anti- bacterial experiments show that the alloy can kill the adhering Escherichia coli effectively. Since the Ag element plays a key role in killing the adhered bacteria, microstructures of Ag and Ag-rich compounds were characterized by scanning electron microscopy and transmission electron microscopy. Ag-rich compounds with the size of a few microns were found to be embedded within the matrix and along grain boundaries, Moreover, pure Ag particles with a lattice parameter of 0.422 nm were found within the austenite matrix. The orientation relationship between the matrix and Ag particles was identified. Nano-sized Ag particles were precipitated during heat treatment, and the interfacial energy between Ag precipitates and matrix was determined by Becket＇s model calculation.
A 304 stainless steel with the addition of 0.27 wt% Ag was found to exhibit excellent antibacterial properties. Based on Thermo-Calc calculation, a special heat treatment was introduced to obtain Ag precipitate in this steel. Anti- bacterial experiments show that the alloy can kill the adhering Escherichia coli effectively. Since the Ag element plays a key role in killing the adhered bacteria, microstructures of Ag and Ag-rich compounds were characterized by scanning electron microscopy and transmission electron microscopy. Ag-rich compounds with the size of a few microns were found to be embedded within the matrix and along grain boundaries, Moreover, pure Ag particles with a lattice parameter of 0.422 nm were found within the austenite matrix. The orientation relationship between the matrix and Ag particles was identified. Nano-sized Ag particles were precipitated during heat treatment, and the interfacial energy between Ag precipitates and matrix was determined by Becket＇s model calculation.
基金
supported by the National Basic Research Program of China (No. 2011GB108006)
