• 1 Department of Mechanical Engineering, Universiti Teknologi Petronas, Seri Iskandar 32610, Malaysia
  • 2 Department of Mechanical and Materials Engineering, University of Jeddah, Jeddah 21589, Saudi Arabia
  • 3 Chemical Engineering Department, University of Jeddah, Jeddah 21589, Saudi Arabia
  • 4 School of Mechanical Engineering, University of Leeds, Leeds LS2 9JT, UK
  • 5 School of Mechanical & Manufacturing Engineering, National University of Sciences and Technology (NUST), H-12, Islamabad 44000, Pakistan
  • 6 Department of Materials Science and Engineering, INSIGNEO Institute of in Silico Medicine, University of Sheffield, Sheffield S1 3BJ, UK
  • 7 Department of Materials Science and Engineering, Kulliyah of Engineering, International Islamic University Malaysia, Kuala Lumpur 50728, Malaysia
Materials (Basel), 2021 Jun 28;14(13).
PMID: 34203154 DOI: 10.3390/ma14133597


Together, 316L steel, magnesium-alloy, Ni-Ti, titanium-alloy, and cobalt-alloy are commonly employed biomaterials for biomedical applications due to their excellent mechanical characteristics and resistance to corrosion, even though at times they can be incompatible with the body. This is attributed to their poor biofunction, whereby they tend to release contaminants from their attenuated surfaces. Coating of the surface is therefore required to mitigate the release of contaminants. The coating of biomaterials can be achieved through either physical or chemical deposition techniques. However, a newly developed manufacturing process, known as powder mixed-electro discharge machining (PM-EDM), is enabling these biomaterials to be concurrently machined and coated. Thermoelectrical processes allow the migration and removal of the materials from the machined surface caused by melting and chemical reactions during the machining. Hydroxyapatite powder (HAp), yielding Ca, P, and O, is widely used to form biocompatible coatings. The HAp added-EDM process has been reported to significantly improve the coating properties, corrosion, and wear resistance, and biofunctions of biomaterials. This article extensively explores the current development of bio-coatings and the wear and corrosion characteristics of biomaterials through the HAp mixed-EDM process, including the importance of these for biomaterial performance. This review presents a comparative analysis of machined surface properties using the existing deposition methods and the EDM technique employing HAp. The dominance of the process factors over the performance is discussed thoroughly. This study also discusses challenges and areas for future research.

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.