Developing high strength and ductility in biomedical Co–Cr cast alloys by simultaneous doping with nitrogen and carbon

Abstract

The present study suggested a novel alloy design concept for realizing high-strength Co-Cr-based cast alloys. The proposed strategy is beneficial from the practical point of view because it uses conventional casting approach-a simpler, more cost-effective, industrially friendly manufacturing process than other manufacturing processes such as thermomechanical processing or powder metallurgy. The developed alloys showed the excellent strength-ductility balance and significantly high strength comparable to that of wrought Co-Cr-Mo alloys, while maintaining acceptable ductility and good corrosion resistance. We described the relationship between microstructures and mechanical and corrosion prosperities of the developed alloys; this provides the fundamental aspect of the proposed strategy and will be helpful for further investigations or industrial realization of the proposed strategy.

Biomedical Alloys and Physical Surface Modifications: A Mini-Review

“…Therefore, Co–Cr alloys are commonly used to prepare bone substitutes, usually surrounded by Cl-rich body fluids, which could cause stress- and corrosion-related cracking if 316L stainless steel is used instead of Co–Cr alloy. When Co–Cr alloys are enriched with Cr, stable Cr 2 O 3 film forms and protects the alloy from Cl-ion attacks [ 23 , 42 ]. Yamanaka et al [ 24 ] even used a Co–Cr-based cast alloy for dental applications because of its high strength (comparable to wrought Co–Cr alloys) without ductility loss.…”

Effect of Four Manufacturing Techniques (Casting, Laser Directed Energy Deposition, Milling and Selective Laser Melting) on Microstructural, Mechanical and Electrochemical Properties of Co-Cr Dental Alloys, Before and After PFM Firing Process

“…In the past few years Co-Cr dental alloys have been under continuous development aiming at improving and studying mechanical (such as elastic modulus, yield strength, or ultimate tensile strength) [15,16] and electrochemical properties (corrosion resistance) [17,18]. Moreover, other investigations such as the machinability of these dental alloys [19], their interaction with ceramics used for dental restorations [20] and the effects of cyclic heat treatments [21] have also been performed.…”

CoCrMo alloy as biomaterial for bone reconstruction in oral and maxillofacial surgery: A scoping review.

“…On the other hand, the addition of nitrogen to CoCrMo alloys increases their mechanical strength. 38,39 Better elongation and workability were achieved in the alloy with a nitrogen content of 0.10% of its mass, where the γ-to-ε martensitic transformation was completely suppressed. However, further addition of nitrogen was reported to slightly decrease the elongation to failure because of the enhanced formation of annealing twins.…”