Characterising of internal stresses in duplex coating by FEM

Abstract

The internal stresses in a duplex coating involving a prequenched layer are believed to change if it is exposed to thermal loading. To characterise the internal stresses in such a duplex coating, a gradient model of finite element method is set up. The initial stress within the substrate developed in as quenching and the internal stresses due to the tempering of the prequenched layer (TPQL) in such a duplex coating are calculated. The synthetical internal stresses in coating can be estimated by superposing uniform initial stresses developed during plating. The results indicate that the residual tensile stresses due to fabrication in coating will be decreased greatly, or even synthetical compressive internal stresses may arise in the coating.

Structure and properties of PVD coatings deposited on aluminium alloys

“…Giving new operating characteristics to the commonly known non-ferrous alloys may be frequently obtained by depositing simple monolayer, multilayer, gradient or nanocomposite coatings using the PVD methods. [4][5][6][7][8][9][10] Functional gradient coatings create a new class of coatings, with properties and structure changing gradually. Frequently, a rapid difference between the top coating and substrate properties occurs, causing a stress concentration in this area, both during the manufacturing and operation of the element.…”