Copper-Nickel Alloy Coating on Cast Iron by Cold Spray: Microstructure and Thermal Analysis

Glass containers are manufactured by pressing or blowing a hot glass gob (700-1200°C) onto a metallic mould. Beside forming the glass, moulds are heat exchangers for cooling down the glass final product. To this goal, moulds are made of cast iron or copper-nickel alloy due to their thermal properties. If copper-nickel (nickel aluminium bronze) is the most efficient material, cast iron is mainly used for economic purposes. To enhance the properties of the cast iron mould, cold spray coating of a copper-nickel alloy is investigated. Optimization of the parameters process such as spraying temperature (800-1000°C), pressure (40-50bar) and gun’s travel speed (200-400mm/s) lead to a dense and well-bonded “bronze” coating on cast iron. Microstructural analysis is performed thanks to Optical Microscope, Scanning Electron Microscope, Electron BackScattered Diffraction, X-Rays Diffraction and microhardness tests. Finally, a simple thermal experiment has been designed for demonstrating thermal performances of the coating-substrate couple.