Grant: Alliance Grants

Mining and mineral processing are vital to the Canadian economy. Teck Resources' Trail operation is one of the largest zinc processing and refining facilities in the world, making this operation an essential part of our domestic mining sector. The refinement of zinc-ores to metals requires the use of harsh corrosive chemicals and high temperatures, both of which can be detrimental to the metallic components and systems used to refine the ores. By example, chlorides, sulphuric acid, and high temperatures can lead to rapid corrosion of steel components. Therefore, the surfaces of mineral processing equipment are usually coated with a material that possesses improved high temperature and corrosion properties, such as nickel superalloys. These coatings are usually applied to the surface using traditional arc welding technologies, depositing a relatively thick layer but also imparting considerable heat and stress to the material. Moreover, although many different superalloys are available, a select few are often used (e.g., Inconel 625). Therefore, this research project will investigate the development of higher performance coatings that have less deleterious impacts on the underlying equipment. A laser will be used in place of a welding arc to melt the superalloy material (i.e., laser cladding), in order to melt less underlying base metal, impart less residual stresses in the material, and produce coatings with less surface roughness. Moreover, Inconel 686 will be investigated as a replacement to Inconel 625 for improved corrosion resistance. Laser clad samples will be fabricated using Inconel 686 and will be assessed using advanced characterization methods (e.g., measure coating thickness, determine the extent of melting of the base metal). The laser clad samples will be compared with samples produced by arc welding. Moreover, the corrosion performance of laser clad samples will be evaluated using advanced corrosion testing equipment. Successful laser cladding of Inconel 686 will result in more resilient mining infrastructure that needs less regular cleaning and repair, and improved operating efficiencies, all of which ultimately lead to a cleaner and more competitive Canadian mining sector.