Abstract: A new, cost-efficient and on-site-applicable thermal spraying process for depositing NiAl metallic overlay or bond-coat coatings for high temperature applications by synthesizing the desired intermetallic phases in-flight during oxy-acetylene flame spraying is presented. Base-metal powders were used for spraying and, by adjusting the spraying conditions, excellent NiAl-based coatings were achieved on various substrates, including mild steel, stainless steel and aluminium alloys. Expensive, pre-alloyed or agglomerated powders are avoided and the method is very promising for in-situ work and repairs. We call the new method “Combustion-Assisted Flame Spraying” (CAFSY) and its viability has been demonstrated at a pre-industrial level for coating metallic substrates. The NiAl-based coatings produced by CAFSY exhibit very high integrity with good adhesion, very low porosity, high surface hardness and high erosion resistance at a substantially lower cost than equivalent coatings using pre-prepared alloy powders.
Keywords: combustion-assisted flame spraying (CAFSY); combustion synthesis; flame spraying; intermetallic phases
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Xanthopoulou, G.; Marinou, A.; Vekinis, G.; Lekatou, A.; Vardavoulias, M. Ni-Al and NiO-Al Composite Coatings by Combustion-Assisted Flame Spraying. Coatings 2014, 4, 231-252.
Xanthopoulou G, Marinou A, Vekinis G, Lekatou A, Vardavoulias M. Ni-Al and NiO-Al Composite Coatings by Combustion-Assisted Flame Spraying. Coatings. 2014; 4(2):231-252.
Xanthopoulou, Galina; Marinou, Amalia; Vekinis, George; Lekatou, Aggeliki; Vardavoulias, Michalis. 2014. "Ni-Al and NiO-Al Composite Coatings by Combustion-Assisted Flame Spraying." Coatings 4, no. 2: 231-252.