PREPARATION OF COPPER AND CHROMIUM ALLOYED LAYERS ON PURE TITANIUM BY PLASMA SURFACE ALLOYING TECHNOLOGY

Abstract

Cu – Cr alloyed layers with different Cu and Cr contents on pure titanium were obtained by means of plasma surface alloying technology. The microstructure, chemical composition and phase composition of Cu – Cr alloyed layers were analyzed by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and X-ray diffraction (XRD), respectively. The experimental results demonstrate that the alloyed layers are bonded strongly to pure titanium substrate and consist of unbound Ti , CuTi , Cu 3 Ti , CuTi 3 and Cr 2 Ti . The thickness of Cu 5 Cr 5 and Cu 7 Cr 3 alloyed layer are about 18 μm and 28 μm, respectively. The antibacterial properties against gram-negative Escherichia coli (E.coli, ATCC10536) and gram-positive Staphylococcus aureus (S. aureus, ATCC6538) of untreated pure titanium and Cu – Cr alloyed specimen were investigated by live/dead fluorescence staining method. The study shows that Cu – Cr alloyed layers exhibit excellent antibacterial activities against both E.coli and S.aureus within 24 h, which may be attributed to the formation of Cu -containing phases.