ABSTRACT

In the present work, the effects of oxidising and standard flame spray techniques on microstructure and wear performance of Low Velocity Oxygen Fuel NiWCrBSi coatings produced onto mild steel substrate were studied. Results showed that coating microstructure was dependent on the stoichiometry of the reacting gas mixture. Coatings produced in oxidising flame conditions showed higher amounts of semi-molten particles and high quantity of WC phases. Those coatings showed a good behaviour in dry sliding wear test, due to their higher hardness and the formation of compact and adherent oxide tribofilms. The wear behaviour of non-molten particles against friction forces is discussed, with the aim of establishing relationships between the tribological response of the material and its process-induced microstructure defects.

摘要

在目前的工作中，研究了氧化和标准火焰喷涂技术对低碳钢基材上产生的低速氧气燃料 NiWCrBSi 涂层的微观结构和磨损性能的影响。结果表明涂层微观结构取决于反应气体混合物的化学计量。在氧化火焰条件下生产的涂层显示出更多的半熔融颗粒和大量的 WC 相。这些涂层在干滑动磨损试验中表现出良好的性能，因为它们具有较高的硬度和致密且粘附的氧化物摩擦膜的形成。讨论了非熔融颗粒对摩擦力的磨损行为，目的是建立材料的摩擦学响应与其过程引起的微观结构缺陷之间的关系。