In the present work, processing and hot corrosion behaviour of Inconel718-nano-Al₂O₃ based composite coatings with varying nano-Al₂O₃ contents (10, 20 and 30 wt. %) was studied. The nano-Al₂O₃ powders were synthesised by using manual granulation technique. The composite coatings were deposited on grey cast iron (GCI) substrate by using a high-velocity oxy-fuel process (HVOF). Hot corrosion behaviour of bare and coated specimens was determined at 900 °C in a high-temperature furnace for 50 h. The weight change data was used to establish the oxidation kinetics of bare and coated specimens. The coating with the highest proportion of nano-Al₂O₃ content exhibited the maximum hardness and corrosion resistance. The nano-sized alumina particles enhanced the hardness of the coatings by posing a higher constraint to the plastic deformation during the indentation. The presence of nano-Al₂O₃ and various protective oxides (Cr₂O₃, NiCr₂O₄, and TiO₂) resulted in the improved corrosion resistance of coatings in comparison to the GCI substrate.

在目前的工作中，研究了具有不同纳米Al ₂ O ₃含量（10、20和30 wt％）的Inconel718-纳米Al ₂ O ₃基复合涂层的加工和热腐蚀行为。采用人工造粒技术合成了纳米Al ₂ O ₃粉末。通过使用高速氧燃料工艺（HVOF）将复合涂层沉积在灰铸铁（GCI）基底上。在900℃的高温炉中50小时确定裸露和涂层样品的热腐蚀行为。重量变化数据用于建立裸露和涂层样品的氧化动力学。纳米Al ₂ O ₃比例最高的涂层含量表现出最大的硬度和耐腐蚀性。纳米氧化铝颗粒通过在压痕过程中对塑性变形施加更高的约束来提高涂层的硬度。与GCI基材相比，纳米Al ₂ O ₃和各种保护性氧化物（Cr ₂ O ₃，NiCr ₂ O ₄和TiO ₂）的存在导致涂层的耐腐蚀性提高。