J. Lagerbom, H. T. Koivuluoto, P. Vuoristo, Tampere University of Technology, Tampere, Finland; J. Larjo, Oseir ltd, Tampere, Finland
Alternative to cold spraying (CS), low-pressure cold spraying (LPCS) has raised interest during recent years. LPCS uses less than 10 bar compressed air compared to even 40 bar nitrogen or helium with high flow rate of CS. Only very ductile metals can be sprayed with LPCS and most often only with some added hard powder (usually Al2O3). On the other hand cold spraying using high gas pressures can accelerate pure metals powder particles beyond critical velocity, which is essential for high quality coating formation. There has been discussion about the comparability of LPCS and CS. In this paper comparison between the two methods and especially coatings is conducted in order to find their strong sections.. Deposition efficiencies, particle velocities and overall spraying manageability is discussed. Microstructures, hardness values, adhesion strenghts and other characteristics are investicated. These coating methods have clear differences in coating formation, composition, properties and probably quite different technical applications. At the best these methods can support and complete each other and have their own strengths.
Summary: In this paper comparison between the two methods and especially coatings is conducted in order to find their strong sections.. Deposition efficiencies, particle velocities and overall spraying manageability is discussed. Microstructures, hardness values, adhesion strenghts and other characteristics are investicated. These coating methods have clear differences in coating formation, composition, properties and probably quite different technical applications. At the best these methods can support and complete each other and have their own strengths.
