ZHANG Xiang-yu
,
HUANG Xiao-bo
,
JIANG Li
,
MA Yong
,
FAN Ai-lan
,
TANG Bin
钢铁研究学报(英文版)
Abstract： Stainless steel (SS) is not recommended to be used in hospital environments for work surfaces and door furniture due to the lack of antibacterial properties. To this end, a novel SS surface modified layer with both a quick bacterial killing rate and relatively thick has been obtained by plasma surface alloying with Cu. The microstructure, elements distribution and phase identification were analyzed by SEM, GDS, XRD and XPS. A spread plate method was adopted for evaluation of antibacterial property of specimens against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The experimental results demonstrate that the surface modified layer with the thickness of about 26 μm is uniform and dense. The layer is mainly composed of a mixture of pure Cu, expanded austenite phase and a few Fe3O4 phase. The Cu modified layer exhibits excellent antibacterial effects against E. coli and S. aureus within 1 h. No viable E. coli and S. aureus was found after 3 h (100% killed). The modified layer is relatively thick, hence it is expected that the Cu modified SS will have a durable antibacterial function.
关键词:
Key words: plasma alloying
,
Cu
,
antimicrobial
,
AISI 304 stainless steel
WANG He-feng
,
TANG Bin
,
LI Xiu-yan
钢铁研究学报(英文版)
N-doped TiO2 (N-TiO2) coatings were obtained by oxidation of titanium nitride coatings, which were prepared by the plasma surface alloying technique on stainless steel (SS). The microstructure of N-TiO2 coatings was characterized by X-ray diffraction (XRD), glow discharge optical emission spectrometry (GDOES), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), respectively. Ball-on-disc sliding wear was applied to test and compare the tribological behaviors of the coatings and substrate. XRD patterns showed that anatase type TiO2 existed in the coatings after oxidation. GDOES showed that the resultant coatings had a layered structure, comprising of N-TiO2 layer at the top and a diffusion-type interface. Such a hybrid coatings system showed good adhesion with the substrate. According to XPS, residual N atoms partially occupied O atom sites in the TiO2 lattice. Uniform, continuous and compact coatings were observed by SEM images of coatings after oxidation. Under a load of 7.6 N, the coefficient of friction was in the range of 0.27-0.38 for the N-TiO2/Al2O3 systems and the wear rate of the coatings was only one-fourteenth of that for untreated 316L SS. N-TiO2 coatings displayed much better wear resistance and antifriction performance than SS substrate.
关键词:
plasma surface alloying technique
,
wear resistance
,
stainless steel
,
titanium dioxide
