scholarly journals New Titanium Alloys, Promising Materials for Medical Devices

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5934
Author(s):  
Madalina Simona Baltatu ◽  
Petrica Vizureanu ◽  
Andrei Victor Sandu ◽  
Nestor Florido-Suarez ◽  
Mircea Vicentiu Saceleanu ◽  
...  

Titanium alloys are used in medical devices due to their mechanical properties, but also for their corrosion resistance. The natural passivation of titanium-based biomaterials, on the surface of which a dense and coherent film of nanometric thickness is formed, composed mainly of TiO2, determines an apparent bioactivity of them. In this paper, the method of obtaining new Ti20MoxSi alloys (x = 0.0, 0.5, 0.75, and 1.0) is presented, their microstructure is analyzed, and their electrochemical responses in Ringer´s solution were systematically investigated by linear polarization, cyclic potential dynamic polarization, and electrochemical impedance spectroscopy (EIS). The alloys corrosion resistance is high, and no evidence of localized breakdown of the passive layer was observed. There is no regularity determined by the composition of the alloys, in terms of corrosion resistance, but it seems that the most resistant is Ti20Mo1.0Si.

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaoxing Yan ◽  
Yunting Cai ◽  
Rong Lu ◽  
Tetsuo Miyakoshi

This study investigated the effects of aluminum (Al) mass fraction on the performance of an epoxy-lacquer based coating. The conductivity increased and IR emissivity and gloss decreased with increased Al mass fraction. When the Al mass fraction was decreased from 40% to 30%, the adhesion and impact strength of epoxy-lacquer based coatings increased and were grade 1 and 50 Kg·cm, respectively. When the Al mass fraction was decreased to 10%, the mechanical properties of epoxy-lacquer based coatings decreased. Potentiodynamic polarization and electrochemical impedance spectroscopy of coatings showed that epoxy-lacquer based coating with 30% Al mass fraction has the best corrosion resistance and the lowest porosity. The epoxy-lacquer based coating with the best stability was that of 30% Al mass fraction. Comparing epoxy-lacquer based coating with polyurethane based coating, the epoxy-lacquer based coating presents not only lower emissivity and gloss but also better mechanical properties and corrosion resistance.


2014 ◽  
Vol 789 ◽  
pp. 495-500
Author(s):  
Bing Ying Wang ◽  
Qing Hao Shi ◽  
Wen Long Zhang

The polyurea was modified by adding different amounts of nanometer ZnO. The corrosion behavior of polyurea/primer composite coating system in wet-dry cyclic environment of 3.5% NaCl solution was studied by using the Electrochemical Impedance Spectroscopy (EIS) measurement and adhesion test technology. The experimental result showed that, different mass fractions of nanometer ZnO had different influences on the corrosion resistance property of coating. When the mass fraction of nanometer ZnO was 5%, the composite coating had the largest protective action. The corrosion resistance property of nanometer ZnO can be improved by increasing the density of polyurea coating, however, the corrosion resistance property of polyurea coating will be weakened in case of exceeding the critical adding amount.


Author(s):  
Sajjad Sadeghi ◽  
Hadi Ebrahimifar

Abstract The use of ceramic particles in the matrix of alloy coatings during the electroplating process has received considerable attention. These particles can create properties such as high corrosion resistance, insolubility, high-temperature stability, strong hardness, and self-lubrication capability. Herein, an Ni–P–W–TiO2 coating was deposited on an AISI 304L steel substrate using the electroplating method. Electroplating was performed at current densities of 10, 15, 20, and 25 mA · cm–2, and the effect of current density on microstructure, corrosion behavior, and wear behavior was investigated. The coatings were characterized by means of scanning electron microscopy. To investigate corrosion resistance, potentiodynamic polarization and electrochemical impedance spectroscopy tests were performed in a 3.5% NaCl aqueous solution. A pin-on-disk test was conducted to test the wear resistance of uncoated and coated samples. Sample micro-hardness was also measured by Vickers hardness testing. Examination of the microstructure revealed that the best coating was produced at a current density of 20 mA · cm–2. The results of potentiodynamic polarization and electrochemical impedance spectroscopy tests were consistent with microscopic images. The coating created at the current density of 20 mA · cm–2 had the highest corrosion resistance compared to other coated and non-coated samples. Furthermore, the results of the wear test showed that increasing the current density of the electroplating path up to 20 mA · cm–2 enhances micro-hardness and wear resistance.


2012 ◽  
Vol 585 ◽  
pp. 488-492
Author(s):  
Adeeba F. Khan ◽  
Awanikumar P. Patil ◽  
T. Subba Rao

Cu-10Ni alloy suffers accelerated corrosion in sulfide polluted seawater. As an alternative, a new single phased, Cu-28%Zn-5%Ni-5%Mn-2%Fe alloy (hereby referred as CNZ-alloy) is developed and tested for the corrosion resistance in clean and sulfide polluted synthetic seawater. The CNZ-alloy showed better corrosion resistance than the standard Cu-10Ni alloy in both the test solutions i.e. clean and sulfide polluted synthetic seawater with . The results are discussed on the basis of polarization and electrochemical impedance spectroscopy. The better corrosion resistance of CNZ-alloy is attributed to the formation of protective ZnS and MnS2 films.


2018 ◽  
Vol 4 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Nilesh S. Bagal ◽  
Vaibhav S. Kathavate ◽  
Pravin P. Deshpande

AbstractThe present study aims at deposition of zinc phosphate coatings on low carbon steel with incorporated nano- TiO2 particles by chemical phosphating method. The coated low carbon steel samples were assessed in corrosion studies using electrochemical impedance spectroscopy and potentiodynamic polarization techniques (Tafel) in 3.5% NaCl solution. Morphology and chemical composition of the coatings were analyzed by scanning electron microscopy and energy dispersive X-ray spectroscopy in order to observe growth of coating. Significant variations in the coating weight, porosity and corrosion resistance were observed with the addition of nano- TiO2 in the phosphating bath. Corrosion rate of nano-TiO2 chemical phosphate coated samples was found to be 3.5 milli inches per year which was 3 times less than the normal phosphate-coated sample (8 mpy). Electrochemical impedance spectroscopy studies reveal reduction of porosity of nano-TiO2 phosphate coated samples. It was found that nano-TiO2 particles in the phosphating solution yielded uniform phosphate coatings of higher coating weight, fewer defects and enhanced corrosion resistance than the normal zinc phosphate coatings (developed using normal phosphating bath).


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