正交试验法优选正硅酸乙酯包覆铝粉的条件

Optimization of Tetraethylorthosilicate Coated Aluminum Powder by Orthogonal Tests

为提高铝粉的耐腐蚀性,研究了片状铝粉原料的表面预处理方法,以达到有效除去表面脂肪酸的目的,以正硅酸乙酯为原料,利用溶胶-凝胶法(Sol-Gel)在表面预处理后的铝粉表面包覆一层SiO2薄膜,以达到增加铝粉耐腐蚀性的目的。将包覆完的铝粉置于一定浓度的盐酸溶液中,以相同时间内的析氢量作为评价标准,通过正交试验的极差分析与方差分析优选出最佳的包覆条件。结果显示:铝粉耐腐蚀性的因素影响大小为正硅酸乙酯添加量>温度>时间>H2O添加量>催化剂添加量;包覆15 g铝粉的最佳工艺条件为温度55℃,反应时间6 h,TEOS添加量12 g,H2O添加量16 g,NH3·H2O添加量1 g;采用最佳方案制备的包覆型铝粉具有较好的耐腐蚀性能。

In order to enhance the corrosion resistance of aluminum powders, the pre - treatment method on the flake aluminum powders was studied for removing the oleic acid absorbed on the surface. Using tetraethylorthosilicate (TEOS) as precursor, a dense silica film on the surface of flake aluminum powders was prepared by sol - gel method to increase corrosion resistance. The coated aluminum powder was placed in a certain concentration of hydrochloric acid solution, by comparing the hydrogen gas released in the same time as the evaluation standard. Furthermore ,the optimum conditions for coating had been studied by designing orthogonal test, range analysis and variance analysis. Results showed that the influence order of parameters on corrosion resistance was TEOS addition > temperature > reaction time > H20 addition > catalyst addition. The optimum process conditions for coating 15 g aluminum powders were 55℃of temperature, 6 h of reaction time, 12 g of TEOS, 16 g of H20 and 1 g of NH3 . H20, and the aluminum powder coated under the optimum conditions possessed extremely high corrosion resistance.