Tribological properties of gold matrix composite coatings with carbon nanocapsules containing ionic liquid lubricants

•Production of new self-lubricating coatings by electrochemical deposition on nickel substrate.•Coatings produced by incorporating carbon nanocapsules with ionic liquid (IL) in a gold matrix.•Release of IL lubricant during sliding increases the lifetime of the new galvanic coatings.•Coefficient of friction of the composite coatings is lower than the pure gold coatings. Self-lubricating, gold matrix composite coatings were produced by electrochemical codeposition of carbon nanocapsules filled with ionic liquid (IL) from a colloidal galvanic bath on a nickel electrode. The tribological response of the composite coatings was analysed under sliding conditions against an alumina counterpart. The incorporation of carbon nanocapsules in the coatings decreases the coefficient of friction (CoF) by the release of the IL through a mechanical triggered mechanism. This is based on the cyclic loading of the coating that produces the smearing of gold and breaks the lubricant nanocontainers allowing for the IL to reach the contact surfaces. Lifetime of the galvanic coating, limited by the upsurgence of the nickel substrate when the gold locally breaks, was defined to be around 2.500 cycles while the lifetime of the self-lubricating composite coating could not be determined in the present study (longer than 20.000 cycles).