Abstract
This study demonstrates a method of plasma spraying in which the plasma is maintained in a laminar (rather than turbulent) state, achieving a much greater jet length with less ambient air engulfment. In the experiments, NiCr coatings were produced at spraying distances between 250 mm and 500 mm, showing that specific structures can be realized by changing stand-off distance. Structures with high porosity, for example, are generated at relatively short distances; dense structures, on the other hand, are obtained at longer stand-off distances that allow feedstock powder to reach a fully melted state. XRD analysis shows that the spraying process does not change the chemical composition of the material, and EDS results indicate that chemical and metallurgical bonding are achieved.