Influence of Carbon Concentrations in Reducing Co and Cr Ions Release in Cobalt Based Implant: A Preliminary Report

et al. 2018

MSF

Self Cite

Surface modification of metallic implants is often required to facilitate positive interaction between the implant and the surrounding hard tissue. In the present study, an oxide layer (Cr2O3) was successfully created on a Co-Cr-Mo alloys substrate by using thermal oxidation technique in atmospheric condition. The effect of different carbon content (0.03% and 0.24%) of oxidized Co-Cr-Mo alloys was investigated in terms of its corrosion behavior using electrochemical impedance spectroscopy techniques that immersed in simulated body fluid. The corrosion tests were repeated for five times for each of sample condition. The results demonstrated that thermal oxidation and carbon content have correlation in influencing the corrosion performance in Co-Cr-Mo alloys. A high carbon content sample generates a lower corrosion-rate compared to low carbon content sample even though all samples were treated at similar oxidation temperature and time duration. Observation also showed that less diffusion of cobalt released in high carbon sample which is believed has effects in creating the uniformity and dense oxide layer without any presence of microcracks and delamination. This phenomenon can be concluded that carbon content in Co-Cr-Mo alloy have influenced in controlling the reaction of metal elements during thermal oxidation which is beneficial in formation of oxide layer. The uniformity and compact oxide layer substantially have enhanced the corrosion resistance of high carbon Co-Cr-Mo alloy.

Section: Introductionmentioning

confidence: 84%

“…The surface roughness of all substrate was measured using Mitutoyo SJ-301 surface profilometer while the average roughness of ground samples obtained was 0.1±0.02 µm. Ground samples were left to dry for overnight in the oven at 50ºC before they were taken for next process [15]. Thermal Oxidation Process.…”

Section: Methodsmentioning

confidence: 99%

Effect of Thermal Oxidation and Carbon Concentrations on Co-Cr-Mo Alloy in Enhanced Corrosion Protection

Mas-Ayu

Daud

et al. 2018

MSF

Self Cite

“…The biocompatible is one of the most fundamental requirements for choosing a metallic implant that is, involving the acceptance of an artificial implant by the surrounding tissues and biological system [1]. Currently, the metallic materials have approved and commonly used in structural implants include stainless steel, cobalt-chromium (CoCr) alloys and titanium (Ti) alloys (Table 1).…”

Section: Introductionmentioning

confidence: 99%

Performance Enhancement of Energy Saving and Machining Characteristic in Electrical Discharge Machining on Magnesium Alloy: A Review

Juraimi

Hassan

et al. 2020

ARFMTS

Self Cite

Magnesium alloys have been widely used in biodegradable applications due to it tends to corrode inside the human body and combined with its initial mechanical property. Current research revealed that the structural stability of the implant is disturbed and lost rapidly due to the increased rate of degradation of magnesium inside the human body. Because of that, non-traditional machining method such as electrical discharge machining (EDM) die sinking process is implemented to create an intricate form with a high tolerance of magnesium alloy. The advantages of EDM are that it allows a versatile adaption of implant behaviour in machining complex 3D structures along with high corrosion resistant properties of electrochemical surface treatment. Various material types with different parameters are investigated to determine the influence of input process parameters on the energy saving, and machining characteristics included surface roughness, material removal rate, and tool wear rate. In addition to improving the machining performance especially in energy-saving, input on the machining parameter needs to be considered due to interaction with added conductive particles which would affect the size of discharge energy. The objective of this paper is to summarize the findings in research of EDM's energy-saving and machining characteristics on magnesium alloy and to explore challenging issues that need to be resolved for future references and recommendations.

“…Common surface modification techniques include Chemical Vapor Deposition (CVD) [10], Physical Vapor Deposition (PVD) [11][12][13][14], Ion Implantation [15], Plasma Spray coating [16], Sol Gel [17,18], Nitriding [19], and Thermal Oxidation [20,21]. Among these, the PVD technique shows promising results by offering a low processing temperature (<500 • C) over a wide range of coating thicknesses as compared to other methods.…”

Section: Introductionmentioning

confidence: 99%

The Influence of Ultrasonic Vibration Frequency on the Properties of TiN Coated Biomedical Ti–13Zr–13Nb

Izman

Ismail

et al. 2018

Metals

Self Cite

Bare biomedical grade titanium alloys are prone to degradation when in a body fluid environment. Surface coatings such as Physical Vapor Deposition (PVD) can serve as one of the options to minimize this issue. Past reports showed that the PVD coated layer consists of pores, pinholes, and columnar growths which act as channels through which the aggressive medium attacks the substrate. Duplex and multilayer coatings seem able to address this issue to varying extents but at the expense of manufacturing time and cost. In this paper, the effect of an ultrasonic vibration frequency on PVD TiN coated Ti-13Zr-13Nb biomedical alloy was studied. Disk type samples were prepared and coated with TiN at fixed conditions: bias voltage (−125 V), substrate temperature (300 • C), and nitrogen gas flow rate (300 standard cubic centimeters per minute (SCCM)). An ultrasonic vibration was then subsequently applied to the TiN coated samples at frequencies of 8 kHz and 16 kHz for 5 min. All TiN coated samples treated with ultrasonic vibrations exhibited a higher corrosion resistance than the untreated ones. Microstructure analysis under Field Emission Scanning Electron Microscopy (FESEM) confirmed that the coated sample at frequencies of 16 kHz produced the most compact coating. It is believed that the hammering effect of the ultrasonic vibration reduced the micro channels' size in the coating and thus decelerated the corrosion's attack.