Structure and corrosion resistance of Ti/TiC coatings fabricated by plasma immersion ion implantation and deposition on nickel–titanium (original) (raw)
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Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2005
Nickel-titanium shape memory alloys (NiTi) are useful materials in orthopedics and orthodontics due to their unique super-elasticity and shape memory effects. However, the problem associated with the release of harmful Ni ions to human tissues and fluids has been raising safety concern. Hence, it is necessary to produce a surface barrier to impede the out-diffusion of Ni ions from the materials. We have conducted acetylene, nitrogen and oxygen plasma immersion ion implantation (PIII) into NiTi alloys in an attempt to improve the surface properties. All the implanted and annealed samples surfaces exhibit outstanding corrosion and Ni out-diffusion resistance. Besides, the implanted layers are mechanically stronger than the substrate underneath. XPS analyses disclose that the layer formed by C 2 H 2 PIII is composed of mainly TiC x with increasing Ti to C concentration ratios towards the bulk. The nitrogen PIII layer is observed to be TiN, whereas the oxygen PIII layer is composed of oxides of Ti 4+ , Ti 3+ and Ti 2+ .
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2006
Nickel-titanium shape memory alloys (NiTi) have potential applications as orthopedic implants because of their unique super-elastic properties and shape memory effects. However, the problem of out-diffusion of harmful Ni ions from the alloys during prolonged use inside a human body must be overcome before they can be widely used in orthopedic implants. In this work, we enhance the corrosion resistance of NiTi using carbon plasma immersion ion implantation and deposition (PIII&D). Our corrosion and simulated body fluid tests indicate that either an ion-mixed amorphous carbon coating fabricated by PIII&D or direct carbon PIII can drastically improve the corrosion resistance and block the out-diffusion of Ni from the materials. Results of atomic force microscopy (AFM) indicate that both C 2 H 2-PIII&D and C 2 H 2-PIII do not roughen the original flat surface to an extent that can lead to degradation in corrosion resistance.
Effect of TiO 2 -Ti and TiO 2 -TiN composite coatings on corrosion behavior of NiTi alloy
Surface and Interface Analysis, 2014
Two kinds of biocompatible coatings were produced in order to improve the corrosion resistance of nickel titanium (NiTi) alloy. A titanium oxide-titanium (TiO 2 -Ti) composite was coated on NiTi alloy using electrophoretic method. After the coating process, the samples were heat-treated at 1000°C in two tube furnaces, the first one in argon atmosphere and the second one in nitrogen atmosphere at 1000°C. The morphology and phase analysis of coatings were investigated using scanning electron microscopy and X-ray diffraction analysis, respectively. The electrochemical behavior of the NiTi and coated samples was examined using polarization and electrochemical impedance spectroscopy tests. Electrochemical tests in simulated body fluid demonstrated a considerable increase in corrosion resistance of composite-coated NiTi specimens compared to the non-coated one. The heat-treated composite coating sample in nitrogen atmosphere had a higher level of corrosion resistance compared to the heat-treated sample in argon atmosphere, which is mainly due to having nitride phases.
Wear and corrosion behaviour of Ti-based coating on biomedical implants
Surface Engineering, 2020
Biomedical implants are immensely manoeuvered devices that fix various deformities and injuries on medical grounds. With an emergent exploration in this field by researchers, countless combinations of materials have been discovered that perks global mankind. The ultimate goal of this experimentation is to appraise the characteristics of wear and corrosion resistance of Ti-Co-Cr-coated 316L grade austenitic stainless steel (SS) in contrast with TiNcoated and uncoated 316L SS. A micro-abrasion test was conducted on every single sample at 3N, 5N and 7N loads and were characterized in accordance with weight loss, coefficient of friction, surface roughness, Scanning Electron Microscope (SEM) analysis, X-ray Diffraction pattern (XRD), Energy Dispersive X-Ray Analysis (EDAX), Fourier-transform infrared spectroscopy (FTIR) and corrosion resistance. The findings showed that Ti-Co-Cr-coated substrate at 3N load have good mechanical tolerance and offers admirable performance. The corrosion resistance of the specimens divulges the biocompatibility of Ti-Co-Cr as being more distinct because of the existence of titanium metal.
Journal of Biomedical Materials Research Part A, 2007
Stainless steel and titanium alloys are the most common metallic orthopedic materials. Recently, nickel-titanium (NiTi) shape memory alloys have attracted much attention due to their shape memory effect and super-elasticity. However, this alloy consists of equal amounts of nickel and titanium, and nickel is a well known sensitizer to cause allergy or other deleterious effects in living tissues. Nickel ion leaching is correspondingly worse if the surface corrosion resistance deteriorates. We have therefore modified the NiTi surface by nitrogen plasma immersion ion implantation (PIII). The surface chemistry and corrosion resistance of the implanted samples were studied and compared with those of the untreated NiTi alloys, stainless steel, and Ti-6Al-4V alloy serving as controls. Immersion tests were carried out to investigate the extent of nickel leaching under simulated human body conditions and cytocompatibility tests were conducted using enhanced green fluorescent protein mice osteoblasts. The X-ray photoelectron spectroscopy results reveal that a thin titanium nitride (TiN) layer with higher hardness is formed on the surface after nitrogen PIII. The corrosion resistance of the implanted sample is also superior to that of the untreated NiTi and stainless steel and comparable to that of titanium alloy. The release of nickel ions is significantly reduced compared with the untreated NiTi. The sample with surface TiN exhibits the highest amount of cell proliferation whereas stainless steel fares the worst. Compared with coatings, the plasma-implanted structure does not delaminate as easily and nitrogen PIII is a viable way to improve the properties of NiTi orthopedic implants. 2007 Wiley
Corrosion and cell adhesion behavior of TiN-coated and ion-nitrided titanium for dental applications
Applied Surface Science, 2005
This study investigated the corrosion resistance and cell adhesion behavior of titanium nitride (TiN)-coated and ion-nitrided Ti substrates for dental applications. The TiN-coated specimen surface layer contained a TiN/Ti structure, while the ion-nitrided specimen contained a Ti 2 N/TiN/Ti structure. The polarization curves in artificial saliva showed that the corrosion rate and passive current for the specimens ranked as: untreated Ti > ion-nitrided Ti > TiN-coated Ti. The polarization resistance obtained from the electrochemical impedance spectroscopy ranked as: TiN-coated Ti > ion-nitrided Ti > untreated Ti. After 24 h osteoblast-like U-2 OS cell incubation on the specimens, the attached cell number occurred in the order: TiN-coated Ti > ion-nitrided Ti > untreated Ti. The TiN-coating and ion-nitriding treatments can improve the corrosion resistance and cell adhesion behavior of Ti. # 2004 Published by Elsevier B.V.
Surface and Coatings Technology, 2016
The surface characteristics and mechanism of corrosion resistance enhancement in a high temperature nitrogen ion implanted medical grade Ti was investigated. The implantations were carried out in a constant energy (80 keV) and dose (2.1 × 10 +18 Ion cm −2 ) at room temperature (~300 K, without heating the substrate) and at different elevated temperatures (473 K, 673 K and 873 K by external heating of the substrate). For implantation temperature optimization, the nitride phase formation on the implanted samples was characterized using grazing incidence X-ray diffraction (GI-XRD) method and also the electrochemical polarization tests in the Ringer's solution as a simulated body fluid were carried out. A significantly enhanced corrosion resistance was achieved for the titanium sample implanted at 473 K between different implantation temperatures, which was attributed to the higher protective performance of the nitride layer over this sample, resulted from the accelerated formation of uniform and dense nitride phases on its surface. The corroded surface of the samples was observed by a field emission scanning electron microscope (FE-SEM). Several delaminations and detachments in the nitride layer were observed over the room temperature implanted sample, however the 473 K implanted sample was relatively intact. The deteriorated corrosion resistance of the 673 K and 873 K samples was attributed to the non-uniformity of the surface and phase transition from α to β-Ti, respectively. For the 473 K implanted sample as a selected implantation temperature, the enhanced corrosion resistance mechanism was investigated more accurately. The surface layer of 473 K implanted sample was studied by a Multi-Beam Focused Ion Beam-Scanning Electron Microscope (FIB-SEM) and was compared with an unimplanted and a 300 K implanted sample. The cross section of samples was channeled using FIB method to study the distribution of nitrogen atoms by EDS mapping technique. The depth profiles of the nitrogen atoms in the implanted samples were also obtained from EDS analysis. Surface feature and roughness of samples were studied by atomic force microscopy (AFM). According to the AFM results, the surface of 473 K implanted sample with uniformly distributed nano-scaled islands, showed a higher roughness value compared to the 300 K implanted one and was predicted to have more compatibility with body tissues. Electrochemical behavior of unimplanted, 300 K and 473 K implanted samples was studied using impedance spectroscopy methods in the Ringer's solution as a simulated body fluid. The mechanism of the corrosion resistance improvement at high temperature implanted sample was developed according to the impedance spectroscopy results.
Ti/TiN MULTILAYER COATINGS FOR ORTHOPEDIC IMPLANTS
2004
Ti/TiN biocompatible multilayers were deposited on 316L stainless steel substrates by reactive magnetron sputtering in nitrogen atmosphere under various deposition conditions. The corrosion behavior of Ti/TiN coatings in artificial physiological solution was investigated using an electrochemical test. Microchemical, microstructural and mechanical characteristics of the coatings were also analyzed.
Coatings
The reactive cathodic arc deposition technique was used to produce Ti nitride and oxynitride coatings on 304 stainless steel substrates (SS). Both mono (SS/TiN, SS/TiNO) and bilayer coatings (SS/TiN/TiNO and SS/TiNO/TiN) were investigated in terms of elemental and phase composition, microstructure, grain size, morphology, and roughness. The corrosion behavior in a solution consisting of 0.10 M NaCl + 1.96 M H2O2 was evaluated, aiming for biomedical applications. The results showed that the coatings were compact, homogeneously deposited on the substrate, and displaying rough surfaces. The XRD analysis indicated that both mono and bilayer coatings showed only cubic phases with (111) and (222) preferred orientations. The highest crystallinity was shown by the SS/TiN coating, as indicated also by the largest grain size of 23.8 nm, which progressively decreased to 16.3 nm for the SS/TiNO monolayer. The oxynitride layers exhibited the best in vitro corrosion resistance either as a monolay...