Potential of electrical discharge treatment to enhance the in vitro cytocompatibility and tribological performance of Co
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Ph.D. Research Scholar, IKG Punjab Technical University, Kapurthala, Punjab 144603, India; and Department of Mechanical Engineering, Khalsa College of Engineering & Technology, Amritsar, Punjab 143001, India 2 Department of Mechanical Engineering, Beant College of Engineering & Technology, Gurdaspur, Punjab 143521, India a) Address all correspondence to this author. e-mail: amitmahajan291@gmail.com Received: 7 March 2019; accepted: 8 July 2019
In the current research, the application and capability of electric discharge treatment (EDT) for enhancing the cytocompatibility and tribological properties of medical-grade Co–Cr alloy were investigated. The Co–Cr specimens were treated by copper tungsten (Cu–W) electrode in a deionized water tank (dielectric medium) at different spark energy levels. To examine the cytocompatibility of substrates, the MTT [3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide] assay was performed to evaluate the substrate cell viability. Furthermore, the wear rate and coefficient of friction of the substrates were examined on a pin-on-disc tribometer. In vitro cytocompatibility results revealed that the % viability of the MG-63 cells on EDT sample was approximately two times improved compared with that on the untreated surface. The tribological results showed that the treated samples have better friction reducing properties and four times higher wear resistance compared with unmachined Co–Cr samples. The surface modification at 10 A current and 60 ls pulse on-time and 150 ls offtime were found as significant parameters in both assessments.
Introduction Biotribology is an integrative research with an aim to assess biological structures and scrutinize their role and characteristics, which eventually focus on improving the aspect and durability of human life [1]. In reconstructive orthopedic surgeries, metals and their alloys have significantly played a preponderant role as constitutional biomaterials [2]. Metals such as stainless steel, magnesium, titanium, and chromium– cobalt are routinely used as implant materials [3]. However, orthopedic doctors and engineers have been continually scuffling for deterrence of early failure of the artificial knee and hip implants. The biomedical science community claimed that the service life of biomaterial implants in the human body has reduced from 30 years to approximately 10–12 years [4]. The duration of the metallic implant is evaluated by its toxic nature and abrasion and wear behavior [5]. Therefore, cytotoxicity, corrosion resistance, and wear resistance are the major considerable aspect to be taken care of to produce a further efficient joint. Wear failure may occur due to the release of
ª Materials Research Society 2019
incompatible metal ions or wear debris in the bone–implant interface [6, 7]. Among the metals and alloys, cobalt–chromium (Co–Cr) alloys provide the best services in the domain of biomaterials for the last 50 years. The Co–Cr alloys, such as F75 (Co–Cr–Mo), F90 (Co–Cr–W–Ni), and F562 (Co–Ni–Cr– Mo), are extensively utilized in den
