【作者】 王晓鹏；

【导师】 魏尊杰； 王宏伟；

【作者基本信息】 哈尔滨工业大学 ， 材料加工工程， 2007， 硕士

【摘要】 本文采用微弧氧化方法在TB2钛合金表面制备氧化陶瓷层,分别在Na₂SiO₃-（NaPO₃）₆和NaAlO₂两种电解液体系中实验。并在氧化过程中改变氧化电源的电参数,观察电参数对微弧氧化过程和陶瓷层最终形貌的影响。利用XRD、SEM、EDS等分析方法对微弧氧化陶瓷层的微观组织结构进行分析,并测试了陶瓷层在滑动摩擦条件下的摩擦学性能。实验表明,微弧氧化陶瓷层表面呈现微孔镶嵌的网格状结构,孔径平均在3⁹μm之间。在同一电解液中,单脉冲的放电能量是决定陶瓷层组织结构的主要因素。电流密度、脉冲电压、脉冲宽度的增加或者脉冲频率的减少都会引起陶瓷层表面粗糙度的增加。陶瓷层的组织成分主要取决于电解液体系。Na₂SiO₃-（NaPO₃）₆电解液体系中陶瓷层主要由金红石相和锐钛矿相组成,并有少量的SiO₂和非晶化合物。在NaAlO₂电解液体系中陶瓷层主要是由Ti₂AlO₅和少量金红石相构成,并有少量白色Al₂O₃晶粒分布在陶瓷层表面。对微弧氧化陶瓷层进行滑动干摩擦实验时,未抛光的陶瓷层与GCr15钢球对磨的摩擦系数都比较大,在0.7⁰.8之间。对陶瓷层进行处理,抛光除去疏松层后陶瓷层与GCr15钢球对磨时的摩擦系数显著降低,在0.2⁰.4之间,但是当摩擦进入后期,对偶钢球发生的氧化磨损机制导致了摩擦系数逐渐增大。陶瓷层涂抹润滑油后,与钢球对磨的摩擦系数降低至0.12。更多还原

【Abstract】 In this paper, in order to obtain good friction characteristic coating on surface of TB2 alloy, Na₂SiO₃-（NaPO₃）₆ and NaAlO₂ coatings were prepared in the corresponding electrolyte system by micro-arc oxidation（MAO） way. During the MAO we also change the parameters of the electrical source, to observe the effect of electrical parameters for the MAO process and morphology. Microstructure of the coatings were analyzed using XRD, SEM, EPMA techniques. The tribological properties of the coatings were evaluated in sliding contact conditions.Experimental results show that MAO coating is puff in the outer layer, with many microspores structure（pore size 3⁹μm）. The microstructures of the coating are mainly dependent on discharging energy of a single pulse in the same electrolyte.The increase of electrical current、impulse voltage、impulse width and the reduce of impulse frequency all can change the smoothness of surface.The microstructure of coatings depends mainly on the type of electrolyte. Coatings which are formed in Na₂SiO₃-（NaPO₃）₆ electrolyte are mainly composed of nano-structure rutile and anatase TiO₂ with small quantity of SiO₂ and some other compounds. The coatings which are formed in NaAlO₂ electrolyte are mainly composed of Al₂TiO₅, with a small amount of Al₂O₃ and rutile TiO₂ compounds.Under dry sliding contact conditions, the unpolished coatings against GCr15 steel ball have high coefficient of friction of about 0.7, which are significantly reduced to 0.25 after polished. The chemical oxidation ware occurring on the GCr15 steel ball surface leads to the gradual increase of coefficient of friction in the later sliding stage. When the coatings were in lubricated wear test, the coefficient of friction rapid reduce to 0.12.更多还原