【作者】 王鹤峰；

【导师】 唐宾； 李秀燕；

【作者基本信息】 太原理工大学 ， 材料科学与工程， 2011， 博士

【摘要】 由于有害细菌的传播和感染,抗菌材料的研究和应用日趋广泛。不锈钢广泛应用于食品工业、厨具、医疗卫生以及日常生活中,对不锈钢进行抗菌处理有重要的意义。本论文以提高不锈钢的抗菌性为锲入点,采用等离子表面合金化和热氧化复合处理技术在316L不锈钢表面形成N掺杂TiO2薄膜。为了对比的需要,本文也在不锈钢表面制备了TiO2薄膜。分别对薄膜的组织结构、基本力学性能、光催化性能、抗菌性能、亲水性能、摩擦性能、腐蚀磨损性能及腐蚀性能进行了较为全面系统的研究。研究结果如下：1、对改性层的组织、成分及结构进行了分析。经TiO2及N掺杂TiO2表面改性后,不锈钢基体表面均形成了均匀致密的改性层,改性层由预渗元素的扩散层或扩散层+镀层组成。扩散层中欲渗元素分布呈梯度变化,增强了改性层结合强度。2、非金属N的掺杂导致TiO2的能隙变窄和吸收边红移,扩大了光响应范围,提高了TiO2的光催化性能。在可见光照射6小时后,N掺杂TiO2对亚甲基蓝溶液的降解率是纯TiO2的1.7倍。3、抗菌试验结果表明,未改性的不锈钢不具有任何抗菌效果。TiO：和N掺杂Ti02改性的不锈钢均显示出明显的抗菌作用；改性后的不锈钢对金黄色葡萄球菌的抗菌效果明显优于大肠杆菌。N掺杂TiO2改性的不锈钢对金黄色葡萄球菌和大肠杆菌的抗菌效果最好,灭菌率分别达到100%和86%。4、通过球-盘磨损试验对改性层的摩擦磨损性能及机理进行了研究。结果表明,干摩擦条件下,与GCr15对摩,Ti2和N掺杂TiO2改性层均表现出优异的减摩和抗磨损性能；与Si3N4对摩,TiO2和N掺杂TiO2改性层虽无减摩效果,但其耐磨性较基材明显改善。改性层相对较高的硬度及与基体间良好的结合强度是TiO2和N掺杂TiO2改性层耐磨性提高的主要原因。5、电化学腐蚀测试结果表明,TiO2及N掺杂TiO2两种表面改性处理均未降低不锈钢在模拟人工体液介质中的耐蚀性,并且N掺杂TiO2改性层比Ti02改性层更具良好的耐腐蚀性能。腐蚀形貌显示：不锈钢基材表面发生点蚀,而经表面改性后的不锈钢均木发生点蚀,表现为均匀腐蚀。6、对316L不锈钢基材、TiO2和N掺杂ZiO2改性层在模拟人工体液介质中的腐蚀磨损性能进行了对比研究。结果表明,TiO2及N掺杂TiO2两种表面改性处理均有不同程度的减摩效果,抗腐蚀磨损性能明显提高,其中N掺杂Ti02改性层在模拟人工体液介质中表现出更好的抗腐蚀磨损性能。更多还原

【Abstract】 The investigation and applications of antibacterial materials have been widely conducted in recent years due to the damaging effect of harmful bacteria. Stainless steel is widely used in food processing equipment, kitchenware, medical apparatus and daily appliances. Thus the development of stainless steel with excellent antibacterial properties is of great significance. With the aim of improving the antibacterial property of stainless steel, N-doped TiO2 films were prepared on stainless steel by plasma surface alloying and thermal oxidation duplex technique. For comparison, TiO2 films were prepared on stainless steel. Meanwhile, surface properties, mechanical performances, photocatalytic activities, antibacterial properties, tribological properties, corrosion-wear behaviors and corrosion properties of films have been studied. The main results have been obtained as follows:(1) The modification layers are composed of a pure diffusion layer or a duplex layer of diffusion layer and surface coating. A gradient distribution of elements existed in modification layer results in improving strength-toughness and enhances bonding strength for modification layers on stainless steel.(2) N-doped TiO2 may result in the real band gap narrowing and consequently a redshif of the optical absorption edge. The visible light photoactivities of N-doped TiO2 were greatly improved as compared with the undoped TiO2. Methylene blue aqueous solution degradation rate of N-doped TiO2 is 1.7 times compared with the undoped TiO2 under visible light for 6 hour.(3) The result of antibacterial test showed that un-modified stainless steel had no antibacterial activity. TiO2 and N-doped TiO2 modification layers increased the rate of cell reduction against Escherichia coli and Staphylococcus aureus. The antibacterial property against Staphylococcus aureus excelled to Escherichia coli obviously in the same condition. N-doped TiO2 modification layer performed excellent antibacterial property against Escherichia coli and Staphylococcus aureus, the rate of cell reduction was 100% and 86% respectively.(4) The tribological properties and mechanism of the modification layers have been studied by ball-on-disc test. TiO2 and N-doped TiO2 modification layer all increase the wear resistance of stainless steel substrate remarkably. Under unlubricated condition, N-doped TiO2 modification layer all have low coefficients of friction and high wear resistance when the coutpart is GCrl5 ball. When the courpart is Si3N4 ball, TiO2 and N-doped TiO2 modification layer have no antifriction effect on stainless steel, but TiO2 and N-doped TiO2 modification layers improve the wear resistance of stainless steel. The excellent wear resistance of TiO2 and N-doped TiO2 modification layer comes from their strong enough load-bearing capacity and bonding strength.(5) Eelectrochemistry tests show that TiO2 and N-doped TiO2 modification layers don’t reduce stainless steel’s corrosion resistance in Hanks’solution. Corrosion resistace of N-doped TiO2 modification layer is better than of TiO2 modification layer. According to the surface topography of corrosion, stainless steel has the phenomenon of pitting corrosion and suface modified stainless steel show uniform corrosion.(6) The corrosion-wear behaviors of stainless steel, TiO2 and N-doped TiO2 modification layers have been studied. In Hanks’solution, TiO2 and N-doped TiO2 modification layers all have smaller coefficients of friction and higher wear resistance than that of stainless steel substrate. Among them, N-doped TiO2 modification layer has better corrosion-wear resistance. The good corrosion-wear performances of TiO2 and N-doped TiO2 modification layers are due to their strong corrosion resistance and wear resistance.更多还原