Structural Characteristics in Cobalt Based Alloys

Résumé

In the present paper there are presented results of investigations on samples of partially removable denture made of cobalt base alloys (Co-Cr-Mo) regarding specific structural analysis: determination of structural phases by quantitative and qualitative microstructural analysis, microhardness determinations versus different casting parameters [1,2,3,4]. By metallographic analysis some important structural aspects may be pointed: the presence of lace eutectic and carbides with discontinuous precipitation in metallic matrix, non-uniform dendritic structure with interdendritic micro-porosities, interdendritic cracks in a structure with fine lace eutectic. Different types of welding were tested, which gave both structural modification and morphology of constituents. Structural modifications which can be made for repairing of prosthesis may diminish mechanical properties of prosthesis, microhardness values of two cobalt base alloys welded by laser technology being high, which may confer a brittle behaviour.