The influence of prosthetic elements manufacturing technology on properties and microstructure shaping Co-Cr-Mo alloys

The presented publication discusses the test results regarding samples of a prosthetic alloy from the Co-Cr-Mo system. The test samples were obtained by means of two different methods applied in prosthetics laboratories to compare their properties and microstructure. To obtain the samples via the traditional lost wax casting method, the cast alloy Co-Cr-Mo was used, commercially known as Wironit LA. In the case of the modern technique DMLS (Direct Metal Laser Sintering), metallic powder Co-Cr-Mo, called EOS Cobalt Chrome MP1, was used. The samples of both Co-Cr-Mo alloys obtained via the two methods were prepared for metallographic tests; they also underwent microstructural observations with the use of light microscopy (LM) and scanning electron microscopy (SEM), and next they were subjected to hardness tests. The obtained samples demonstrated a dendritic structure. In the samples cast with the lost wax casting method, a segregation of the chemical composition was revealed. The samples obtained by means of the DLMS method were characterized by chemical composition homogeneity. The hardness measurements with the statistical analysis of the measurement results showed a difference between the examined alloys. On the basis of the performed studies, it was stated that the applied methods of manufacturing prosthetic elements make it possible to obtain diversified microstructural and mechanical properties of the alloys. The hardness value significantly affects the subsequent mechanical and finishing treatment of prosthetic elements, such as metal bases of crown caps, bridges, mobile prostheses or other retention elements.