ABSTRACT

High-velocity oxyfuel (HVOF) sprayed ceramic coatings possess less porosity and exceptional cohesive strength as compared to the air plasma sprayed ceramic coatings. In particular, the HVOF-sprayed tungsten carbide-cobalt (WC-Co) coatings have the disadvantage of unexpected brittle fracture. These coatings usually fail at higher levels of stress because of their lower fracture toughness that results due to decarburization occurring during the deposition of the coatings. In this work, the HVOF-sprayed nanostructured WC-25wt-%Co coatings have been investigated with and without the addition of rGO. It was found in the microstructure of 1.5% rGO-added WC-25wt-%Co coatings that the rGO has been pulled out from the matrix and wrapped in the fractured regions. It was also observed with an increasing percentage of rGO addition that the porosity in the WC-25wt-%Co coatings has been reduced due to a reduction in the number of pores.

摘要

与空气等离子喷涂陶瓷涂层相比，高速火焰 (HVOF) 喷涂陶瓷涂层具有较小的孔隙率和出色的内聚强度。特别是，HVOF喷涂碳化钨钴（WC-Co）涂层具有意外脆性断裂的缺点。这些涂层通常在较高的应力水平下失效，因为它们的断裂韧性较低，这是由于涂层沉积过程中发生的脱碳造成的。在这项工作中，我们对添加和不添加 rGO 的 HVOF 喷涂纳米结构 WC-25wt-%Co 涂层进行了研究。在添加 1.5% rGO 的 WC-25wt-%Co 涂层的微观结构中发现，rGO 已从基体中拉出并包裹在断裂区域中。