Crack-free wear resistance coating on carbon steel obtained by directed energy deposition of Fe-base partial amorphous powders

Abstract

Laser Directed Energy Deposition of an Fe-base partial amorphous powder was carried out to study the feasibility of manufacturing partial amorphous coatings without macroscopic defects and high hardness values onto carbon steel substrates for wear resistance applications. Cold cracking can be avoided by preheating the substrate beyond 400 °C. Process parameters optimization can also guarantee fully dense coatings with hardness values above 800 HV. Results from x-ray diffraction correlate the high hardness to the crystallite size of the matrix phase and the presence of hardness enhancer phases, such as borides/carbo-borides and amorphous microstructure. Finally, wear resistance analyses on the coatings revealed an excellent response and confirmed the potential of combining this technology with Fe-base amorphous materials to increase wear resistance.

Keywords

• Directed energy deposition
• Coating
• Cold cracking
• Wear resistance
• Preheating