Abstract
The development of coatings has become a technologically significant aspect in many industries. A common approach in high temperature applications is the production of new thermal barrier coatings (TBCs) [1]. The Laser cladding (LC) can be an alternative method to thermal spraying for the production of high quality bond coats in TBCs [2]. In this work, dense coatings with adequate metallurgical bond with the substrate by overlap coaxial laser cladding were obtained. The oxidation behavior of the coatings specimens was assessed by air furnace oxidation tests at 1100 °C for up to 200 h. The coatings microstructure is composed of a γ matrix phase and β dendritic phase, confirmed by DRX. At high temperature, the growth and formation of oxides layers provide protection of the underlying coating and substrate from oxidation at elevated temperature. The possible formation and morphology of oxides on the oxidized surface has been evaluated by Scanning Electron Microscopy (SEM) and Atom Force Microscopy (AFM). The evaluation of thickness and phases presents in thermally grown oxide scale was evaluated by Field Emission Scanning Electron Microscopy (FESEM) and Energy Dispersive Spectroscopy microanalysis (EDS), with previous cut by Focused Ion Beam Ga Column (FIB) method.
