Nowadays, the events of bacterial infection, food poisoning and biological corrosion damage are increasingly arising. It is urgent to develop new antibacterial material to fight against the drug-resistant bacteria. In this work, Ag-bearing antibacterial duplex stainless steels were prepared by adding Ag or Cu-Ag alloy particles. The microstructure and distribution of Ag-rich phases and Ag electrovalence of the materials after solution treatment at different temperatures have been discussed in detail by ESEM, XRD and TEM. The antibacterial effects of the materials were tested by film-cover method, and compared with CD4MCu and Cu-bearing antibacterial duplex stainless steel. The results indicated that some Ag-bearing phases in diameter of about 8 mu m in the matrix of the material prepared by adding Ag after the solution treatment at 1050 and 1150 degrees C were observed, and increasing temperature could not improve the solution solubility of Ag-bearing phases. In addition, some Ag-bearing phases in diameter of 45 nm was found in the matrix of the material after solution treatment at 1150 degrees C. For the material prepared by adding Cu-Ag alloy particles after solution treatment at 1050 and 1150, the solubility of Ag-bearing phases increased with the solution temperature rising. And the smaller the Cu-Ag particles were, the easier the Ag-bearing phases dissolved. For the material prepared by adding Cu-Ag alloy particles in diameter of 150 similar to 300 mu m after the solution treatment at 1150, Ag-bearing particles were completely dissolved into gamma phase while some in diameter of about 18 nm were evenly distributed in a phase. Antibacterial tests showed that Ag-bearing antibacterial duplex stainless steels prepared by adding different sizes of Cu-Ag alloy particles exhibitted excellent antibacterial effect. The material prepared by adding Ag granules had the antibacterial effect.
