Wire arc spraying is a coating process in which minor modifications of the configuration and spray parameters
can have a strong impact on coating characteristics. A study on the effects of the fluid dynamics
of the atomizing gas on the coating properties is presented. Different types of nozzles, shrouds, and gases
have been used to provide various flow velocities and reactive environments in the metal atomization region.
The effects on particle velocity, coating density, composition, and interface characteristics between
the coating and the substrate have been evaluated. It is clear that higher gas velocities improve practically
all coating properties, but also increase oxide content in the coating. However, the oxidation can be
drastically reduced if nonoxidizing gases are used for atomization in combination with a shroud. A discussion
on the physical effects contributing to the observed adhesion improvements and interfacial properties
is provided.