溶胶-凝胶法制备TiO_(2)及其冷喷涂性能研究

The Cold Spraying Performance of TiO_(2) Prepared by Sol-gel Method

冷喷涂陶瓷涂层的现有研究表明,大部分商业陶瓷粉末不适合用于冷喷涂,而实验室制备的纳米团聚粉末更易于冷喷涂。溶胶-凝胶法是制备纳米TiO_(2)最常用的方法之一,具有工艺简单、重复性高、反应易控制等优点,而且可以通过实验参数的改变从分子水平对反应进行控制,从而获得结构形态各异的纳米粒子。本文采用基于钛酸四正丁酯水解反应的溶胶-凝胶法制备纳米锐钛矿TiO_(2),研究粉末的微观结构并考察其冷喷涂性能,在此基础上,分析原料粉末性能对其冷喷涂性能的影响。研究结果表明,与商业TiO_(2)粉末相比,溶胶-凝胶法制备的TiO_(2)粉末具有良好的冷喷涂工艺适应性。溶胶-凝胶法制备的TiO_(2)粉末微观结构为不规则形,经过热处理后由无定形态转变为锐钛矿相。冷喷涂TiO_(2)涂层晶体结构及涂层内部TiO_(2)颗粒的微观形貌均与溶胶-凝胶TiO_(2)粉末保持一致。冷喷涂TiO_(2)涂层的光催化活性受原始喷涂粉末影响,当原始喷涂粉末的光催化活性高时,冷喷涂TiO_(2)涂层的光催化活性也较高。

The existing research on the cold sprayed ceramic coatings indicates that the most commercial ceramic powders cannot be successfully sprayed.Whereas agglomerated nanometer powders prepared in the laboratory can achieve cold sprayed ceramic coating.Sol-gel method is one of the most common used methods to prepare nanosized TiO_(2).It has the advantages of a simple process,low equipment requirement and simple control of the reactions,etc.In order to obtain the nanoparticles of different structure and morphology,the reactions can be controlled at the molecular level through the change of the experimental parameters.In this paper,nanoanatase TiO_(2) was prepared by the hydrolysis reaction of tetrabutyl titanate,and its cold spraying performance was investigated.Moreover,the influence of the powder properties on its cold spray performance was analyzed.The results show that TiO_(2) powders prepared by sol-gel method can be deposited as coatings easier than commercial TiO_(2) powders by cold spray technology.Sol-gel TiO_(2) powders exhibit irregular morphology,and transferred to anatase phase after thermal treatment.The crystal phase and micro-morphology of cold sprayed TiO_(2) coating are the same with sol-gel TiO_(2) powders.The photocatalytic performance of cold sprayed TiO_(2) coating is affected by feed powders.The photocatalytic performance of the cold sprayed TiO_(2) coating has been improved with the increased photocatalytic activity of sol-gel TiO_(2) powders.