Abstract

Cobalt-based alloys are widely used in the manufacture of joint prostheses. In this study, the effect of boron additions and heat treatment on the ASTM F75 was evaluated by rotating bending fatigue. The boron ranged from 0.06–1 wt %. The alloys were tested in as-cast and heat-treated conditions. In the as-cast condition, the infinite life was observed at 380 MPa, improving to 433–615 MPa according to the amount of boron added. In the heat treatment condition, the fatigue resistance was improved only in the base alloy. The addition of 0.06 wt % boron and heat treatment led to the same resistance as in the as-cast condition. Adding large amounts of boron combined with heat treatment diminished the fatigue limit. The fracture analysis revealed primarily brittle behaviour with some ductile features even on the same sample; only the heat-treated alloy with 0.06 wt % boron was clearly ductile. This alloy also exhibited notably better toughness to crack propagation.

Highlights

  • Nowadays, the standard treatment for degenerative joints is to replace them with medical devices, such as knee and hip prostheses, 70–80% of which are made of metallic biomaterials [1]

  • Modifying thethe chemical composition of Co-based alloys via via the addition of B of increased the fatigue fatigue resistance in the as-cast condition according to the amount of B infinite added; infinite life MPa of resistance in the as-cast condition according to the amount of B added; fatigue fatigue life of 615

  • B; this represents an improvement of regarding was observed for the alloy with 1 wt % B; this represents an improvement of 60% regarding the thealloy

Read more

Summary

Introduction

The standard treatment for degenerative joints is to replace them with medical devices, such as knee and hip prostheses, 70–80% of which are made of metallic biomaterials [1]. Titanium alloys present a lower elasticity modulus compared to stainless steel and Co–Cr alloys, which reduce the stress shielding effect [4,5]. Titanium implants are fatigue damaged due to wearing and fretting, which leads to corrosion pits on the surface and a decrease in fatigue resistance [4]. The fatigue process assisted by corrosion has been reported as the failure

Objectives
Methods
Results
Conclusion
Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.