The ASTM F-75 (Co-28%Cr-6%Mo) is widely used as a biocompatible alloy in medicine for manufacturing implants. In this study, effect of mold preheating on the as-cast microstructure of the alloy was investigated using the solid investment casting process. Several mold preheating temperatures of 550, 700, 850 and 1000 °C were selected at the same melt superheat. The samples were characterized by ...

PURPOSE The aim of this study was to evaluate the effects of repeated porcelain firing process on the corrosion rates of the dental alloys. MATERIALS AND METHODS Cr-Co, Cr-Ni and Pd-Ag alloys were used for this study. Each metal supported porcelain consisted of 30 specimens of 10 for 7, 9 and 11 firing each. Disc-shaped specimens 10 mm diameter and 3 mm thickness were formed by melting alloys...

The effect of pre-heat treatments, followed by a hot forging process, on the microstructure and strength of Co–Cr–Mo alloys was investigated. Four pre-heat treatments were conducted at 1170, 1200, 1230 and 1260 C for three different time condition: 2, 6 and 15 h and then water cooled to room temperature. Tensile tests and XRD analyses were carried out on both as-cast alloy and heat-treated allo...

The main aim of this research was to find the mechanism for the failure of the CoCrMo porous nano-composite by characterizing microstructural changes and fractured surface after compression test. For this purpose, porous nano-composites were prepared with the addition of bioactive glass nano-powder to Co-base alloy with 22.5% porosity by the combination of space-holder and powder metallurgy tec...

Removable partial dentures (RPD) are traditionally made of casted alloys using the lostwax technique. Laser-sintering is a new additive manufacturing technique for processing RPD metal frameworks that can produce RPDs frameworks quickly with high precision and at low cost. The objective of this study was to characterize the mechanical, crystallographic, and biocompatibility properties of RPD Co...

Corrosion and metal release mechanisms of CoCrMo alloys are at human biological conditions not fully understood. The main objective of this master thesis was to investigate whether the Vroman effect influences the extent of metal release from CoCrMo alloy in mixed protein solutions. The project focuses on the corrosion properties and release of cobalt (Co), chromium (Cr) and molybdenum (Mo) fro...

A base aluminium-silicon alloy AlSi25Cu5Cr was used to investigate the possibility of alloying aluminium alloys with hard-to-melt elements. The elements Co, Cr and Mo were introduced into melt using metal powder from a hard-melting dental cobalt-chromium-molybdenum alloy. packed in foil studied at temperature 810º C. After mechanical stirring melt, it stood for 30 min. temperature, raised 850º ...

The microstructural and mechanical properties of the hard phases in CoCrMo prosthetic alloys in both cast and wrought conditions were examined using transmission electron microscopy and nanoindentation. Besides the known carbides of M(23)C(6)-type (M=Cr, Mo, Co) and M(6)C-type which are formed by either eutectic solidification or precipitation, a new mixed-phase hard constituent has been found ...