Title: Micro-EDM induced surface modification of titanium alloy for biocompatibility

Authors: M.P. Jahan; Farshid Alavi; Roan Kirwin; Rashef Mahbub

Addresses: Department of Mechanical and Manufacturing Engineering, Miami University, Oxford, OH 45056, USA ' Department of Architectural and Manufacturing Sciences, Western Kentucky University, Bowling Green, KY 42101, USA ' Department of Mechanical and Manufacturing Engineering, Miami University, Oxford, OH 45056, USA ' Department of Mechanical and Manufacturing Engineering, Miami University, Oxford, OH 45056, USA

Abstract: The objective of the current study is to investigate the surface modifications of an implant material Ti-6Al-4V with respect to biocompatibility after machined by micro-electro-discharge machining (micro-EDM). The machined surface characteristics were evaluated by the surface topography, crater sizes, elemental composition, and surface microhardness. It was found that micro-EDM can produce surface roughness lower than 100 microns, which is necessary on the implant surface to promote cell growth around the implant. The roughness of the machined surface can be controlled by controlling the crater sizes, as a direct relationship between crater sizes and discharge energy was observed. A porous and thick titanium oxide (TiO₂) layer was observed on the machined surface, which can induce bony ingrowth into the porous structure, resulting in morphological fixation of the implants to the bone. No known toxic substances were observed on the machined surface of Ti-6Al-4V that could be harmful for human body. Moreover, slight increase in microhardness of the machined surface was observed after micro-EDM, which could be beneficial in biomedical orthodontic applications for wear resistance.

Keywords: Ti-6Al-4V; micro-EDM; surface modification; crater sizes; elemental composition; surface microhardness; biocompatibility.

DOI: 10.1504/IJMMM.2018.093548

International Journal of Machining and Machinability of Materials, 2018 Vol.20 No.3, pp.274 - 298

Received: 19 Aug 2017
Accepted: 02 Nov 2017
Published online: 27 Jul 2018 *

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