Plasma spraying is now a standard coating process to deposit ceramic coatings for applications in automotive, aviation, medical and health care and others. This study deals with a hybrid thermal spray technique to deposit ceramic coatings. This technique named “hybrid-LVOF” (low-velocity oxyfuel) makes it possible to deposit uniform thin or thick ceramic coatings on metallic or ceramic substrates. In this work, the microstructural and mechanical properties of Al2O3 coating deposited by hybrid-LVOF were compared with those of Al2O3 coating deposited by the conventional plasma spray technique. The Rietveld refinement of XRD patterns was used to quantify the α-Al2O3 and γ-Al2O3 coating content. Hybrid-LVOF as-sprayed coatings have a smoother surface, lower porosity (2–3%), higher hardness and better adhesion strength than conventional plasma-sprayed coatings. The hybrid-LVOF coatings also exhibit better fracture toughness probably because of a high inter-splat bonding and low porosity.

中文翻译：

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采用混合 LVOF（低速氧气燃料）工艺的高性能 Al2O3 涂层

等离子喷涂现在是一种标准的涂层工艺，用于沉积陶瓷涂层，用于汽车、航空、医疗和保健等领域。本研究涉及一种混合热喷涂技术来沉积陶瓷涂层。这种名为“混合 LVOF”（低速氧燃料）的技术可以在金属或陶瓷基材上沉积均匀的薄或厚陶瓷涂层。在这项工作中，混合 LVOF 沉积的 Al2O3 涂层的微观结构和机械性能与传统等离子喷涂技术沉积的 Al2O3 涂层的微观结构和机械性能进行了比较。XRD 图案的 Rietveld 细化用于量化 α-Al2O3 和 γ-Al2O3 涂层含量。混合 LVOF 喷涂涂层具有更光滑的表面、更低的孔隙率 (2-3%)、比传统的等离子喷涂涂层具有更高的硬度和更好的附着力。混合 LVOF 涂层也表现出更好的断裂韧性，这可能是因为高的板间结合和低孔隙率。