ABSTRACT

In this study, ZrO₂–Al₂O₃ composite ceramic coating toughened by ZrO₂ nanorods through cathode plasma electrolytic deposition (CPED) was prepared on Al–Si alloy substrate. The microstructure, heat insulation performance, and fracture toughness of the coatings were investigated with SEM, XRD, heat insulation tests, and tensile tests. The ZrO₂ nanorods prepared by the hydrothermal method consist of monoclinic m-ZrO₂ and cubic c-ZrO₂. The ZrO₂ nanorods are staggered in the ceramic coating and partially filled with plasma discharge micropores. The ZrO₂–Al₂O₃ ceramic coating, after adding zirconia nanorods, forms a high-temperature stable mixture of Zr₃Y₄O₁₂, Al₂O₃, and ZrO₂ phases. The duration of hydrothermal during the preparation of ZrO₂ nanorods correlates with the heat insulation temperature of the toughened ceramic coating. The fracture toughness of ceramic coating toughened by ZrO₂ nanorods varies with hydrothermal duration, which can be effectively improved.

摘要

在这项研究中，通过阴极等离子体电解沉积（CPED）在铝硅合金基体上制备了由 ZrO ₂纳米棒增韧的ZrO ₂ -Al ₂ O ₃复合陶瓷涂层。通过SEM、XRD、隔热试验和拉伸试验研究了涂层的微观结构、隔热性能和断裂韧性。水热法制备的ZrO ₂纳米棒由单斜晶系m-ZrO ₂和立方晶系c-ZrO _{2 组成}。ZrO ₂纳米棒在陶瓷涂层中交错排列，部分填充有等离子体放电微孔。ZrO ₂ –Al ₂ O ₃陶瓷涂层在加入氧化锆纳米棒后，形成 Zr ₃ Y ₄ O ₁₂、Al ₂ O ₃和 ZrO ₂相的高温稳定混合物。ZrO ₂纳米棒制备过程中的水热持续时间与增韧陶瓷涂层的隔热温度有关。ZrO ₂纳米棒增韧陶瓷涂层的断裂韧性随水热时间的变化而变化，可有效提高。