Investigation on tribological behaviors of biodegradable pure Zn and Zn-X (Li, Cu, Ge) binary alloys

Huafang Li,Qi Zhang,Jinyan Huang,Peng Zhang

doi:10.1007/s10856-021-06625-4

Huafang Li, Qi Zhang + Show 2 more

Open Access

https://doi.org/10.1007/s10856-021-06625-4

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Abstract

As a potential biodegradable implant material, zinc (Zn) alloys have attracted increasing attention due to their good biocompatibility and moderate degradation rate. Zn and its alloys are expected to become candidate materials for medical devices. The metals implanted in the human body will inevitably undergo friction in the human body before it is completely degraded. Friction and wear are essential factors which may cause medical devices’ service failure. However, there are still few studies on the friction and wear properties of biodegradable Zn-based alloys in the human body, and most studies just focus on the mechanical properties, degradation properties and biocompatibility of the alloys. Thus, it is crucial to study the friction and wear properties of Zn and its alloys. In the present work, we investigated the tribological properties of biodegradable pure Zn and Zn-X (Li, Cu, Ge) alloys. Our study found that under simulated body fluid and dry friction conditions, the addition of alloying elements Li and Cu can improve the friction properties of Zn. Among the four metals, Zn-0.5Li alloy has the lowest friction coefficient and the best wear resistance. Hank’s solution has lubricating and corrosive effects. That is to say, when the alloy is rubbed in Hank’s solution, it can not only be protected by the lubrication of the solution, but also tribocorrosion will occur as well.

Highlights

Biomedical metallic materials include traditional bioinert metallic materials for load-bearing and biodegradable metals
Traditional bioinert metals that are permanently implanted in the body require a second operation to be removed from the patient after implantation
It can be seen that coefficient of friction of the four metals presented some fluctuation during sliding

Summary

Introduction

Biomedical metallic materials include traditional bioinert metallic materials for load-bearing and biodegradable metals. Biodegradable metals (BMs) are ideal temporary implant materials because of their good degradability and biocompatibility [1]. Due to good mechanical properties and corrosion resistance, many traditional bioinert metals (such as Ni-Ti, Ti-Nb, Ti-6Al-4V, etc.) have been used in biomedical applications for bone implants and heart valves [2]. BMs degrade gradually after implantation and promote complete healing of local tissues. It avoids the need for a second removal surgery, thereby reducing patient’s medical costs and physical pains [1, 3]. As a new type of biodegradable metal, Zn-based alloys have attracted increasing attentions due to their moderate corrosion rate, good biocompatibility, and physical properties [11, 12]. Pure zinc can improve its mechanical properties through alloying treatment (such as adding elements Li [14], Mg [15], Ca [16], Ge [17] and Cu [18])

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