Processing and Tribological Properties of PEO Coatings on AlZn5.5MgCu Aluminium Alloy with Incorporated Al-Cu-Fe Quasicrystals

Abstract

The modification of ceramic PEO coatings developed for friction units is in trend of modern research aimed at the improvement of friction and wear. This study presents ceramic coatings formed on AlZn5.5MgCu aluminum alloy by microarc oxidation (PEO) in a one-stage technological process with inclusions of Al-Cu-Fe quasi-crystals. The technology of rubbing quasi-crystals into the surface of the coating during final polishing was also used. Friction and wear tests, followed by analysis of the surface and cross-sections by SEM microscopy, showed that quasicrystals affect the coating structure and frictional characteristics. The addition of a small amount of modifier to the electrolyte (0.5 percent), as well as rubbing-in technology, can reduce the coefficient of friction (up to 16 percent) and wear rate (up to 43 times) compared to pure ceramic coatings. More modifier provides a negative result.