Mechanical Behaviour of Functionally Graded Composite Vitreous Enamelled Steel Sheets

Among various coatings for industrial and engineering applications, vitreous enamel ones have advantages of chemical inertness, high temperature stability and superior mechanical properties with reference to abrasion or impact as a comparison to other coating materials applied by thermal spraying. The enamelled composite, due to its internal composition, functionalization and architecture can be considered as a functionally graded composite material. In the present work, a first systematic characterization of the mechanical behaviour of enamelled steel sheets is presented. Tests were performed under four-point bending load with displacement control and acoustic emission monitoring. The mechanical response of tested materials was used to determine some key elastic parameters (e.g. Young Modulus), and the First Crack Failure parameter. Moreover, the mechanical performance of tested coated specimens was also related and discussed with reference to microstructure, surface characteristics, and residual strains in the coated structure