Heat treatment of thermally sprayed Ni-based wear and corrosion coatings

Currently there are various types of thermal spray coatings available for wear and corrosion protection and their performance is greatly dependant on the level of porosity inherent in these coatings. This study focuses on Nickel-based coatings produced by Thermal spray technology followed by Flame or Laser heat treatment to produce a dense, well adhered, and relatively porous free microstructure that enhances corrosion and wear resistance. The results show that heat treatment produces a strong metallurgical bond with the substrate which in turn increased the coating adhesion and reduces porosity. A unique coating adhesion test was developed to measure the high coating strengths and the microstructure and mechanical properties compared with coatings produced without heat treatment. It is believed that laser heat treatment of thermal spray coatings can produce cost effective coatings with enhanced corrosion and wear properties for the manufacturing industry.