磷酸盐溶液中纯铝微弧氧化陶瓷层磨损特性研究

Study on Wear Characteristics of Micro-arc Oxidation Coating on Pure Aluminum in Phosphate Electrolyte

研究了纯铝在磷酸盐处理液中微弧氧化陶瓷层的生长机理,并分析了陶瓷层的磨损特性。采用扫描电镜和能谱分析仪观察和分析了陶瓷层磨损前后的微观形貌和元素分布,结合TT260测厚仪、数显千分尺分析了陶瓷层的生长规律。利用盘-盘式磨损试验机测试了陶瓷层磨损性能,分析了磨损机理。结果表明:陶瓷层由Al、O、Si、Fe构成,无处理液中的Na、P、N、C、F存在,说明在磷酸盐处理液中纯铝微弧氧化陶瓷层是由基体成分与氧反应烧结形成的氧化物组成。在相同磨损条件下,微弧氧化陶瓷层试样比纯铝试样的耐磨性显著提高,磨损机理为磨粒磨损并带有从裂纹处的片状剥落。

Growth mechanisms of micro-arc oxidation coating on pure aluminum were investigated in phosphate electrolyte and the wear characteristics were analyzed. The microstructure and elements distribution of the coating before and after wearing were observed using SEM and EDS. The growth process of ceramic coating was analyzed using TT260 thickness gauge and digital micrometer. The wear characteristics were measured with disk-on-disk abrasion tester, then wear mechanism was discussed. The results show that the micro-arc oxidation ceramic coating contains A1, O, Si and Fe elements without Na, P, N, C and F elements in the treatment solution, resulting in formation of ceramic coating through oxidation combining with substrate and oxygen. Under the same dry wear condition, the wear performance of micro-arc oxidation samples is notable higher than pure aluminum samples. The wear mechanism of micro-arc oxidation coating is abrasive wear with lamellar structure stripping from initial micro-cracks.