CORROSION BEHAVIOR AND ROUGHNESS OF NI-CR/AL2O3 COMPOSITES AS DENTAL RESTORATIVE

Abstract

This work investigated on the corrosion behavior and roughness of Ni-Cr alloy as dental restorative. Alumina with three weight percentages (1, 5 and 10%) added as reinforcement to fabricate Ni-Cr/alumina composites. Corrosion behavior was tested in artificial saliva at 37+1 oC and pH=4.4. The data of corrosion indicated that the addition of alumina led to reduce the dissolution of metals in base alloy due to the enhancing of Cr2O3 passive film and producing Ni3Al phase in matrix. The roughness of surface was reduced for composites compared with base alloy (Ni-Cr) which is important factor to reduce the accumulation of bacteria on restorative materials in mouth; this reduction is due to the formation of ductile Ni3Al compared with brittle Ni2Cr3 in composites.