Analysis of Two-phase flows for Spraying Processes

热喷涂广泛应用于航空航天、汽车、发电和生物医学行业，为暴露于热、腐蚀和磨损的起落架、发动机、涡轮机和植入物部件提供保护涂层。在传统的热喷涂系统中，例如等离子体、高速氧燃料（HVOF）或冷喷涂，具有数十微米尺寸的涂层颗粒被供给到喷嘴中，在喷嘴中它们被加热并加速到高速。因此，热喷涂涂层通过熔融或半熔融颗粒流在表面上的冲击和固化而形成。我们设计并制造了一种护罩附件，该附件大大扩展了HVOF工艺在沉积效率和灵活性方面的能力，允许使用陶瓷粉末进行涂覆（美国专利号6，845，929）。

Thermal sprays are extensively used in the aerospace, automotive, power generation, and biomedical industries to provide protective coatings on landing gear, engine, turbine, and implant components that are exposed to heat, corrosion, and wear. In a conventional thermal spray system such as plasma, high velocity oxygen fuel (HVOF), or cold spray, coating particles with a size of tens of microns are fed into the spray nozzle where they are heated and accelerated to high velocities. Consequently, thermally sprayed coatings are formed by the impact and solidification of a stream of molten or semi-molten particles on a surface. We have designed and built a shroud attachment which considerably expands the capabilities of the HVOF process in the areas of deposition efficiency and flexibility to allow coating with ceramic powders (U.S. Patent No. 6,845,929).