摘要
The alumina composite coatings reinforced with 25% ZrO2 (denoted as AZ-25) and 3% TiO2 (denoted as AT-3) were deposited on low carbon steel using a thermal flame spraying. The microstructure, phase composition, microhardness and tribological properties of the coatings were investigated. The XRD results of the coatings reinforced by TiO2 (AT-3) revealed the presence of α-Al2O3 phase as matrix and new metastable phases of α-Al2O3 and α-Al2O3. However, the coatings reinforced by ZrO2 (AZ-25) consist of α-Al2O3 as matrix, q-ZrO2 and m-ZrO2. In most studied conditions, the AT-3 coating displays a better tribological performance, i.e., lower coefficient of frictions and wear rates, than the AZ-25 coating. It was also found that the microhardness of the coatings was decreased with the reinforcement of ZrO2 and increased with TiO2.
采用火焰热喷涂技术在低碳钢表面上沉积制备添加25%ZrO_2(简称AZ-25)和3%TiO_2(简称AT-3)增强体的Al_2O_3涂层,对涂层的显微组织、相组成、显微硬度和摩擦学性能进行了研究。X射线衍射(XRD)结果表明,AT-3涂层的主要相组成为α-Al_2O_3,此外还含有一些亚稳的β-Al_2O_3和κ-Al_2O_3相。而AZ-25涂层的主要相组成为α-Al_2O_3,还有一些q-ZrO_2和m-ZrO_2相。在大多数实验条件下,AT-3涂层的摩擦学性能(摩擦因数、磨损率)均比AZ-25涂层要好。添加ZrO_2增强体会导致涂层的显微硬度降低,而添加TiO_2会使涂层硬度增加。
作者简介
Corresponding author: Mohand Amokrane BRADAI; Tel/Fax: +213-34-21-51-05; E-mail: mokbrad@yahoo.fr