Effect of cerium on mechanical, metallurgical and biomedical properties of NiCrMoB dental alloy

Abstract

NiCrMo alloys are popular as non-precious dental casting alloys and appreciated specially in developing nations. A number of elements may be alloyed to achieve enhanced characteristics suitable for dental restorations. In this study NiCrMo dental casting alloy was alloyed with cerium to improve mechanical, metallurgical and biomedical characteristics. Three alloys were produced by vacuum induction melting technique. These cast alloys were tested for melting range, phase analysis, microstructure, mechanical and wear characteristics, corrosion behavior, coefficient of thermal expansion and biocompatibility properties. Test results revealed that 0.4% cerium addition in NiCrMoB alloy substantially improved the mechanical, metallurgical and corrosion characteristics of the cast alloy without compromising the biocompatibility and melting characteristics of the alloy. Mechanical testing and tribological results pointed out that the NiCrMoB alloy with 0.4% addition of cerium possessed tensile strength up to 515 MPa with impact strength around 7 J, while average coefficient of friction was calculated to be 0.1715; that was least of the investigated alloys. Corrosion rate for the alloy was found to be 25.92 × 10−3 mils per year that was also the least among the investigated alloy samples.