Effect of different sintering conditions on microstructural characterisation of Co-Cr metal laser powder

Abstract

Co-Cr alloys have been used for many years in dentistry. In recent years, the fabrication of prosthetic restorations from Co-Cr alloys by metal laser sintering method has become widespread. This method is a combination of powder metallurgy and three-dimensional printing technologies. The surface microstructure of the material and the different phases formed on the surface of the material after sintering and heat treatment are extremely important since these metal substructures are layered with dental porcelain in fixed prosthetic dentistry. In this study, characterisation of Co-Cr alloy samples produced by direct metal laser sintering (DMLS) method and sintering under various atmospheric conditions were performed with X-ray diffractometer (XRD), scanning electron microscope (SEM) and energy-dispersive X-ray diffractometer (EDX). It was observed that sintering with different methods under various atmospheric conditions affected the XRD phase intensities. The sintering in the argon gas atmosphere yielded a more significant phase separation that facilitates the identification of different phases in XRD patterns.