Cu-bearing, martensitic stainless steels for applications in biological environments

Effect of Aging Temperature on the Microstructure and Properties of Economical Duplex Stainless Steel

“…The copper-rich phase with rods growing up to 300 nm reportedly exceeded the thickness of the passivation film [34]; hence, the exposed ε-Cu phase on the surface did not form a passivation film. During sterilization, Cu 2+ was formed by the action of the ε-Cu phase with water covering the passivation film, and the released Cu 2+ was mainly sterilized by two routes: First, the cell wall was perforated when the Cu 2+ penetrated to the bacteria and some intracellular substances leaked out, leading to bacterial death [35]. Second, when Cu 2+ entered the microbial cells, it was bound to the enzymes in the bacteria and destroyed the enzymatic system in the bacterial cells.…”

Morphology and Antibacterial Properties of Copper Precipitates in Ferrite Stainless Steel

“…The antibacterial function can be attributed to the presence of Cu 2+ , which can kill Escherichia coli and Staphylococcus aureus (Ref 14 , 15 ). Thus, Cu solid solution into a matrix cannot provide the antibacterial function unless copper is precipitated and grown to a certain size (Ref 16 , 17 ).…”

A Novel Design to Enhance the Mechanical Properties in Cu-Bearing Antibacterial Stainless Steel

“…However, only if the copper element precipitates out as copper precipitation and grows to a certain size can the copper precipitation kill the bacteria. When the copper element dissolved in the matrix or the size of copper precipitation is too small, the material cannot receive the antibacterial function [12][13][14]. So far, most copper-bearing ferritic antibacterial stainless steels are annealed at 800 • C to obtain rod-shaped copper precipitation with lengths of about 500 nm and widths of about 50 nm.…”