Influence of the Increased Atomizing Gas Pressure on Microstructure and Mechanical Properties of Arc Sprayed Coatings

The cored wires of the Fe-Cr-B-C-Al system have been used and an influence of the spraying parameters on the microstructure and mechanical properties of the arc sprayed coatings have been investigated. It was established that an increase of atomizing gas pressure from 0.6 up to 1.2 MPa causes decreasing of spraying flow divergence angle and increasing of melted drops velocity up to 1.5-1.7 times. A time of interaction of the atomised drops with the oxygen strongly reduces. A formation of thinner oxide film is observed. Size of melted drops does not exceed 50 μm. These particles undergo stronger deformations during an interaction with the surface if to compare with drops, which form at spraying pressure of 0.6 MPa and have a size up to 150 μm. A displacement of surface oxide films in the contact area is more intensive and improvement of the coating’s cohesion 1.5…2 times was reached.