Investigation of Cu coatings deposited by kinetic metallization

Interfacial characterisation of Kinetic Metallization (KM) sprayed Cu coatings applied on metal substrates was performed using optical and electron microscopy as well as microindentation hardness testing and microchemical analysis The interfacial characterisation of KM coatings remains scarce to date Cross sectional observations of KM coatings on light metal substrates revealed an undulating, patelliforrn profile with thin lipped cusps at the interface Pure Al and Mg substrates exhibited a mechanically impinged zone <similar to 5 mu m on the substrate material, approximately the size of deformed Cu powder particles Examination of the Cu side of the interface indicated there was no long range interaction in the coating On the substrate side of the interface the KM process induced phase transformations e recrystallisation and an alloyed zone) in thin layers contiguous to the interface on pure Al and Mg substrates Zones of elemental interdiffusion were identified at the interface upon Al and Mg substrates using scanning TEM The width of intermixing zones was in the vicinity of <1 mu m This metallurgical interaction at the interface occurred on the length scales involving the initial single layer of Cu particles bonded on the substrate (C) 2010 Elsevier Inc All rights reserved