Surface Roughness of Plasma Sprayed Coatings: A Statistical Approach

Thermal spraying produces coatings with relatively rough surfaces compared to other deposition methods. In this work, NdFeB coatings were deposited on stainless steel by plasma spraying at various standoff distances. Some of the coatings were also annealed. Surface roughness profiles of as-sprayed and heat-treated coatings were measured by contact profilometry and analyzed via statistical methods. The effect of standoff distance and annealing on roughness is discussed along with the significance of measurement direction and evaluation length.