Preparation and Corrosion Resistance of Cold Sprayed Al - based Composite Coating

Abstract

Aluminum alloy is widely used for its light weight characteristic and excellent corrosion resistance. Cold spraying technology is one effective method to fabricate the Al anti - corrosive coatings owing to its high speed and low temperature deposition characterization. In this work, the aluminum powder was mixed with ceramic phase powder to prepare the composite powder by mechanical mixing, and Al5056/Al5056 - Al2O3/Al5056 - SiC/Al5056 - WC coatings were prepared by cold spraying on the Al1060 substrate. The porosity and content of the ceramic phase in the coating were studied through Image - Pro Plus software, and microhardness testing was carried out on the composite coatings. Meanwhile, the effects of ceramic types on the electrochemical properties of composite coatings were studied, and the corrosion resistance of the coating was analyzed in combination with the corrosion morphology. Results showed that the ceramic phase could be effectively deposited, but the self aggregation of ceramic particles during the spraying process affected the compaction of the coating. Besides, Al5056 and Al5056 - Al2O3 coatings exhibited high impedance modulus, but the self corrosion current density and corrosion rate of Al5056 - Al2O3 coatings were reduced by an order of magnitude compared with other coatings. Thus, the Al5056 - Al2O3 coating showed the best corrosion resistance performance.

Keywords

• cold spraying|ceramic phase|al - based composite coating|corrosion resistance