ΜΗΧΑΝΙΚΗ ΚΑΙ ΗΛΕΚΤΡΟΧΗΜΙΚΗ ΣΥΜΠΕΡΙΦΟΡΑ ΜΕΤΑΛΛΙΚΩΝ ΚΑΙ ΚΕΡΑΜΙΚΩΝ ΕΠΙΣΤΡΩΜΑΤΩΝ ΠΛΑΣΜΑΤΟΣ

Abstract

ALUMINA (AI2O3) AND MOLYBDENUM WERE PLASMA SPRAYED ON VARIOUS SUBSTRATES. THE MECHANICAL BEHAVIOUR OF THE COATED SYSTEMS WAS EXAMINED. THE TENSILE STRENGTH WAS FOUND TO DECREASE WITH INCREASING COATING THICKNESS. THE BOND STRENGTH OF THEALUMINA COATING WAS FOUND INDEPENDENT OF THE SUBSTRATE'S ROUGHNESS. ABRASSIVE WEAR RATE OF THE ALUMINA COATING WAS INITIALLY HIGH AND WAS DEPENDENT OF THE COATING'S ROUGHNESS. EXCIMER LASER (KRF) WAS EMPLOYED FOR THE MODIFICATION OF THECOATINGS SURFACES. THE LASER CAUSED A WAVY TOPOGRAPHY ON THE COATING SURFACE. ROUGHNESS OF THE COATING WAS INCREASING WITH INCREASING LASER POWER DENSITY ANDTHE NUMBER OF PULSES. FINALLY, THE CORROSION BEHAVIOUR OF THE MOLYBDENUM COATING WAS THOROUGLY STUDIED AND THE MECHANISMS OF THE CORROSION WERE EXAMINED. LASER TREATMENT OF THE COATING IMPROVED ITS CORROSION RESISTANCE.