Corrosion Behavior of Fe-Al Alloy Modified with Cr and Ti in Simulated Physiological Human Media (original) (raw)
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Effect of Ni on the corrosion behavior of Fe–Al intermetallics in simulated human body fluid
Journal of Solid State Electrochemistry, 2007
The corrosion behavior of FeAl-type intermetallic alloy in the Hank's solution has been investigated after additions of 1, 3, and 5 at.% Ni with or without thermal annealing at 400°C for 144 h. Techniques included potentiodynamic polarization curves, linear polarization resistance, and change of the free corrosion potential with time and electrochemical noise in current. Regardless of the heat treatment, additions of Ni increased both the free corrosion potential and the pitting potential values. Additionally, both the corrosion current and the passive current densities were reduced with this element. The alloys which did not suffer from pitting type of corrosion were the heattreated FeAL base alloy and the one containing 5Ni. Both additions of Ni and thermal annealing improved the adhesion of external protective layer either by avoiding the formation of voids or by lowering the number of precipitates and making them more homogenously distributed.
Journal of Bio- and Tribo-Corrosion, 2020
The stainless steel alloys are greatly utilized for human orthopaedic and implants. The electrochemical behaviour of the stainless steel of Fe-17Cr-xNi alloys (x = 8, 10, 14) has been studied in simulated body fluid containing H 2 O 2 and albumin at 37 °C. The electrochemical behaviour of the Fe-17Cr-8Ni, Fe-17Cr-10Ni and Fe-17Cr-14Ni has been investigated using the potentiodynamic polarization and electrochemical impedance spectroscopy, EIS. The surface morphology of the three alloys was examined before and after immersion in the simulated body fluid containing H 2 O 2 and albumin using scanning electron microscope. The elemental composition of the oxide layer formed on the surface of the alloys after immersion in the electrolyte was obtained using energy dispersive X-ray analysis, EDX, technique. The metals released into the electrolyte has been determined using atomic absorption spectrophotometry. The EIS and potentiodynamic polarization results demonstrate that the Fe-Cr-14Ni alloy attains highest polarization resistance and the smallest rate of corrosion than Fe-17Cr-8Ni and Fe-17Cr-10Ni alloys. Fe-17Cr-14Ni is slightly influenced by immersion in simulated body fluid containing H 2 O 2 and albumin which is confirmed by SEM images and metal release via formation of protective passive film. The surface analysis has shown the participation of the different alloying elements in the passive film.
Electrochemical corrosion properties of metal alloys
This study concerns an investigation of the corrosion behavior of 316 stainless steel, CoCrMo and Ti6Al4V alloys in simulated body conditions (ringer lactate) at 37 C by the use of Tafel plots, mixed potential and electrochemical impedance spectroscopy (EIS). Ti6Al4V alloy has the highest corrosion resistance followed by CoCr alloy. Ti6Al4V–CoCrMO was the best couple for galvanic corrosion with the minimum galvanic potential and current values according to mixed potential theory and Tafel method. It was concluded that Ti6Al4V was the most suitable material for implant applications in the human body.
Electrochemical Performance of Fe40Al-X (X = Cr, Ti, Co, Ni) Alloys Exposed to Artificial Saliva
Materials, 2020
Fe–Al intermetallic compounds have been considered excellent candidates as alternative alloys for various applications in corrosive environments compared to other Fe-based alloys. Their excellent corrosion resistance is due to the development of an Al-based passive layer. The performance of the passive layer can be improved by adding a third alloy element. Therefore, in this study the electrochemical performance of the Fe40Al intermetallic alloy modified by the addition of a third alloy element (Cr, Ti, Co, Ni) is evaluated. The corrosion resistance of intermetallic alloys has been evaluated by electrochemical tests (potentiodynamic polarization curves, and measurements of open circuit potential, linear polarization and electrochemical impedance) in artificial saliva. The performance of intermetallic alloys was compared with that of Ti. The results obtained showed that the addition of Ni and Ti substantially improves the corrosion resistance of the base intermetallic. The corrosion ...
Electrochemical behavior of Ni-Al-Fe alloys in simulated human body solution
Journal of Solid State Electrochemistry, 2010
An investigation about the corrosion resistance of Ni-Al-Fe intermetallic alloys in simulated human body fluid environments has been carried out using electrochemical techniques. Tested alloys included 57 (wt%) Ni-(20 to 30) Al-(12 to 23) Fe using the Hank's solution because the high corrosion resistance provided by protective Al 2 O 3 external layer. For comparison, AISI 316L type stainless steel has also been used. Electrochemical techniques included potentiodynamic polarization curves, electrochemical impedance spectroscopy, and electrochemical noise measurements. The different techniques have shown that these alloys showed a similar or higher corrosion resistance than conventional AISI 316L type stainless steel, and this corrosion resistance decreased as the Al content in the alloy increased. The alloys were susceptible to pitting type of corrosion on the interdendritic Ni-rich phases.
Purpose: The paper presented results of corrosion resistance investigations with FeAl intermetallic phase matrix and different aluminium content (38%, 40% and 42%). Design/methodology/approach: In the corrosion research electrolyser, potentiostat "Solartron 1285" and computer with "CorrWare 2" software were used. Results of the research were worked out with "CorrView" software. The potential's values were determined in relation to normal hydrogen electrode (NEW). The temperature of the solutions was kept on 21ºC level. The recording of potential/density of current-time curve was conducted for 300 s. Sample polarization ranges from potential smaller by 300 mV from normal potential to 0 mV in case of the test in 0.2% HCl solution as well as to 1500 mV in case of 3% H 2 SO 4 solution. Rate of changing the potential amounted 10 mV/min in each case. Observations of the surface state were conducted using scanning electron microscope (JSM-35) with magnifications from 30 to 1000. Findings: The results were showed that electrochemical corrosion conducted in 0,2% HCl and 3% H 2 SO 4 solution depend on aluminium content. The best electrochemical corrosion resistance in 0.2%HCl have samples of Fe-38Al intermetallic phase based alloy and in 3% H 2 SO 4 have Fe-40Al. It was confirmed by the lowest value of corrosion current density, low value of passive current density, pitting corrosion resistance much higher than in other samples. Research limitations/implications: The results of potentiodynamic research of alloy examined in 0.2% HCl solution are presented in table 1, these for 3% H 2 SO 4 in table 2. Results of the potentiostatic and galvanostatic tests are presented in table 3. In figures 1, 2 the potentiodynamic curve are presented. Table 4 presents results of the surface state after corrosion tests. Figures 3-8 present surface state of the samples after corrosion research, which was observed using the scanning electron microscope. Originality/value: Corrosion resistance in liquid media of FeAl intermetallic phase.
Corrosion Behavior of Ni-Al-Cu Alloys in Simulated Human Body Solution
2011
An investigation about the corrosion resistance of Ni-Al-Cu intermetallic alloys in simulated human body fluid environments has been carried out by using electrochemical techniques. Tested alloys included 50 (wt %) Ni-(20 and 25) Al-(20 and 25) Cu using the Hank ́s solution. For comparison, 316L type stainless steel has also been evaluated. Electrochemical techniques included potentiodynamic polarization curves, linear polarization resistance (LPR), electrochemical impedance spectroscopy (EIS), and electrochemical noise measurements, EN. Different techniques have shown that, generally speaking, Ni-Al-Cu alloys showed a lower corrosion resistance than conventional 316L type stainless steel only during a few days. Their corrosion resistance decreased as the Cu content in the alloy decreased. The alloys were susceptible to pitting type of corrosion on the ’-(Ni, Cu)3Al Curich phases.
Corrosion study of Fe-Al Intermetallic Alloys in Simulated Acid Rain
This paper presents an investigation on the corrosion resistance of iron aluminides FeAl-based alloys, in an environment that simulates acid rain water in temperature room. Potentiodynamic Polarization, Linear polarization resistance curves Rp, Nyquist data and Bode curves obtained by electrochemical impedance spectroscopy were used to study the corrosion behavior of two intermetallic compounds. Showed that the binary alloy FeAl exhibited the greatest resistance to corrosion while the alloy Fe 3 Al showed the lowest resistance to corrosion. Intermetallic Fe 3 Al alloys had greater susceptibility to pitting corrosion. While FeAl intermetallic alloys showed low corrosion rate.
Electrochemical Behavior of Cu-Al-Ni Alloy in Simulated Body Fluids
— The electrochemical comparative studies between, Cu-Al-Ni alloy as a non-precious casting alloy and a pure Ti as a common biomaterial were investigated in simulated body fluid (SBF). The aim of the work was to evaluate the corrosion resistivity of these alloys in the simulated body fluids, using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements. The surface morphology of the alloys was examined via the scanning electron microscopy. This comparison was focused on the effect of the solution chemistry and immersion time on the passivity of the alloys. The influence of albumin, as a model protein, and a fluoride ion with its simulated dose in a human body, on both biomaterials was investigated. The Albumin has enhanced the corrosion resistance of both samples. On the contrary, fluoride ion increased their corrosion rate in all the tested solutions. The electrochemical behavior of Ti has shown a higher transfer resistance and a lower capacitance compared with the copper alloy. However, the resistivity of both materials increased with immersion time in the different solutions.
Corrosion of Al2O3-Ti composites under inflammatory condition in simulated physiological solution
Materials Science and Engineering: C, 2019
Alumina-titanium composites have shown good mechanical properties which makes them promising for orthopedic applications. The placement of an orthopedic implant involves an invasive procedure which stimulates a localized inflammatory response causing an acidic environment around the implant. This makes the study on corrosion more critical. Therefore, the aim of the present paper was to study the corrosion behavior of the composites with 75vol.% and 50vol.% Ti content (with alumina balance) fabricated by Spark Plasma Sintering under acidic condition representing inflammation and in two elapsed times (1h and 1-day) using polarization and electrochemical impedance spectroscopy tests. For comparison, the experiments were also conducted in normal physiological solution after 1h, and pure Ti (100vol.%Ti) was fabricated by the same process and analyzed, similarly. Furthermore, behavior of the samples was studied after 48 days of immersion in the acidic and normal solutions using SEM, ATR-FTIR, AFM, and ICP-OES. The results of corrosion tests showed very good passivation behavior of 100vol.%Ti and the composite containing 75vol.%Ti. The superiority of the 75vol.%Ti composite in corrosion characteristics in both solutions was also found. Its corrosion resistance was 20.3 MΩcm 2 under the inflammatory condition after 1-day, which was 39% higher than that of 100vol.%Ti under the same condition. The results of SEM indicated both corroded and mineral deposition zones on all materials' surfaces and the ATR-FTIR results revealed additional adsorbed bands related to water adsorption, OH and carbonate groups after immersion. The AFM analysis showed rougher morphology, particularly for 75vol.% Ti where the Rq was increased about 50 nm, and the ICP-OES results indicated 65.87% and 61.94% deposition of solution calcium on 75vol.%Ti and 50vol.%Ti, respectively. The acidic/inflammatory condition influenced the corrosion processes of all materials. Lower pH caused the passivation to occur sooner and the corrosion resistance to be higher.