Effect of Age Hardening Treatment on the Corrosion Resistance of AA6061, SiC and Fly ash Powder Metallurgy Composites

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
S. Muthukumar
Keyword(s):  
Silicon Carbide ◽  
Corrosion Resistance ◽  
Fly Ash ◽  
Powder Metallurgy ◽  
Hybrid Composites ◽  
Base Material ◽  
Age Hardening ◽  
Localized Corrosion ◽  
General Corrosion ◽  
Hardening Treatment

Identification of corrosion resistance through electrochemical methods for silicon carbide and fly ash reinforced metal matrix composites in automobiles is mandatory. In the present work, the composite developed through powder metallurgy process is studied for corrosion resistance. The effect of constant proportion of fly ash (10% wt.) and varying proportion of silicon carbide (5% wt., 10% wt., 15% wt.) on electrochemical corrosion resistance of aluminium alloy AA6061 base material is investigated. The sintered hybrid composites as well as age hardened composites particles were examined under Scanning Electron Microscope (SEM-EDS) to verify the elemental nature of the corroded material. The potentiodynamic polarization technique based corrosion rate measurements exhibited localized corrosion in the sintered hybrid composites. Severely corroded material closer to interface of reinforcements and matrix was observed in addition to attack on the matrix. Age hardening treatment improved the corrosion resistance of hybrid composites in which only general corrosion was observed.

scholarly journals Assessment of nickel titanium and beta titanium corrosion resistance behavior in fluoride and chloride environments

2013 ◽  
Vol 83 (5) ◽  
pp. 864-869 ◽  
Author(s):  
Elisa J. Kassab ◽  
José Ponciano Gomes
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Fluoride Concentration ◽  
Nickel Titanium ◽  
Localized Corrosion ◽  
General Corrosion ◽  
Nacl Solution ◽  
Galvanic Coupling ◽  
Beta Titanium

ABSTRACT Objective: To assess the influence of fluoride concentration on the corrosion behavior of nickel titanium (NiTi) superelastic wire and to compare the corrosion resistance of NiTi with that of beta titanium alloy in physiological solution with and without addition of fluoride. Materials and Methods: NiTi corrosion resistance was investigated through electrochemical impedance spectroscopy and anodic polarization in sodium chloride (NaCl 0.15 M) with and without addition of 0.02 M sodium fluoride (NaF), and the results were compared with those associated with beta titanium. The influence of fluoride concentration on NiTi corrosion behavior was assessed in NaCl (0.15 M) with and without 0.02, 0.04, 0.05, 0.07, and 0.12 M NaF solution. Galvanic corrosion between NiTi and beta titanium were investigated. All samples were characterized by scanning electron microscopy. Results: Polarization resistance decreased when NaF concentration was increased, and, depending on NaF concentration, NiTi can suffer localized or generalized corrosion. In NaCl solution with 0.02 M NaF, NiTi suffer localized corrosion, while beta titanium alloys remained passive. Current values near zero were observed by galvanic coupling of NiTi and beta titanium. Conclusions: There is a decrease in NiTi corrosion resistance in the presence of fluoride. The corrosion behavior of NiTi alloy depends on fluoride concentration. When 0.02 and 0.04 M of NaF were added to the NaCl solution, NiTi presented localized corrosion. When NaF concentration increased to 0.05, 0.07, and 0.12 M, the alloy presented general corrosion. NiTi corrosion resistance behavior is lower than that of beta titanium. Galvanic coupling of these alloys does not increase corrosion rates.

scholarly journals Study on Microstructure and Mechanical Properties of Al7068 Reinforced with Silicon Carbide and Fly Ash by Powder Metallurgy

2021 ◽  
Vol 7 (09) ◽  
pp. 47-53
Author(s):  
Md Mehtab Alam and B.S Motgi
Keyword(s):  
Mechanical Properties ◽  
Silicon Carbide ◽  
Fly Ash ◽  
Powder Metallurgy ◽  
Aluminum Matrix ◽  
Hydraulic Press ◽  
Powder Form ◽  
X Ray ◽  
Microstructure And Mechanical Properties ◽  
Scanning Electron

The paper deals with detailed study on microstructure and mechanical properties of aluminum 7068 reinforced with fly ash and silicon carbide by powder metallurgy, aluminum 7068, silicon carbide and fly ash were taken in powder form of required size and mixed together in varying proportion according to specification and compacted with pressure of 400MPa using hydraulic press to make samples and then samples were sintered at 600°c for 2 hours, the samples were tested for density, compressive strength, hardness and microstructure was analyzed using scanning electron microscope, energy dispersive x-ray study was carried out in order to confirm presence of silicon carbide and fly ash in aluminum matrix.

General Corrosion Behavior of N06022 in Super Concentrated Brines at Temperatures Higher than 100°C

2008 ◽  
Vol 1124 ◽  
Author(s):  
Raul B. Rebak
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Localized Corrosion ◽  
General Corrosion ◽  
Short Term ◽  
Corrosion Resistant ◽  
Electrochemical Tests ◽  
Alloy 22 ◽  
Nickel Based Alloy ◽  
Anions And Cations

AbstractAlloy 22 (N06022) is a highly corrosion resistant nickel based alloy. Extensive research has been conducted in the last eight years on the corrosion behavior of Alloy 22, mainly regarding its resistance to localized corrosion. Less attention has been paid to the general corrosion resistance in highly concentrated brines that may result from the deliquescence of salts contained in dust. Salts such as mixtures of NaCl, KCl, CaCl2, NaNO3, and KNO3 may deliquesce at temperatures above 100°C through absorption of moisture from the air. Electrochemical tests were used to assess the general corrosion behavior of Alloy 22 in brines with chloride and nitrate concentrations ranging from 8 molal to 100 molal in the temperature range 100 to 160°C. The effect of mixed anions and cations was also studied. Results show that, even for short-term immersion periods, the corrosion rate of Alloy 22 in high temperatures super concentrated brines is generally below 10 μm/year.

The Effect of Alloying Cu on Pitting Corrosion Resistance of Copper-Bearing Ferritic Stainless Steel

2008 ◽  
Vol 569 ◽  
pp. 197-200 ◽  
Author(s):  
Wei Zhang ◽  
De Ning Zou ◽  
Hong Hong Yao ◽  
Jun Yang
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Pitting Corrosion ◽  
Stainless Steels ◽  
Antibacterial Properties ◽  
Ferrite Matrix ◽  
Localized Corrosion ◽  
General Corrosion ◽  
Pitting Corrosion Resistance ◽  
Effect Of Alloying

Copper is a well-known alloying element which is used to improve the resistance to general corrosion of stainless steels. Our previous experiments show that the increase of copper content can acquire the excellent antibacterial properties and can also increase the tendency to cold formability of the ferritic stainless steels. However, the effect of alloying Cu on the resistance to localized corrosion has not been clarified sufficiently. In order to understand the effect of copper on pitting corrosion resistance of the ferritic antibacterial stainless steel, the electrochemical experiments were carried out and the anodic polarization curves were performed in 3.5% NaCl solution for two kinds of steels. The results reveal that the ε-Cu phase in ferrite matrix diminishes pitting corrosion resistance of the antibacterial stainless steel in the chlorides medium. It is connected with the poor passive behavior of the ε-Cu phase inclusions.

scholarly journals Effect of Nitrogen on the Corrosion Behavior of Austenitic Stainless Steel in Chloride Solutions

2015 ◽  
Vol 9 (11) ◽  
pp. 119 ◽  
Author(s):  
W. A. Ghanem ◽  
W. A. Hussein ◽  
S. N. Saeed ◽  
S. M. Bader ◽  
R. M. Abou Shahba
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Austenitic Stainless Steel ◽  
Electrochemical Impedance ◽  
Open Circuit ◽  
Localized Corrosion ◽  
Partial Replacement ◽  
General Corrosion ◽  
Heat Treated ◽  
The Difference

The effect of partial replacement of nickel with nitrogen on the corrosion resistance of newly designed austenitic stainless steel samples without and with heat treated was investigated in 3.5wt% and 5wt% NaCl solution using open-circuit, potentiodynamic, cyclic anodic polarization and electrochemical impedance spectroscopy techniques. The results showed that, passivation in sample 1 where the highest addition of nickel and low addition of nitrogen is different from that for sample 4 where the nitrogen is greatest and the nickel is reduced almost to the third comparing sample 1. The difference in responses of heat treated samples to localized and general corrosion could be attributed to the difference in their phase compositions. The appearance of ferrite phase for samples (2, 4, 5 and 6) after heat treatment resulted in lowering the general and localized corrosion resistance than as forged samples in contrast with samples 1 and 3, where they still pure austenite. The obtained results are confirmed by surface examination.

Effect of Silicon Carbide Boron Carbide and Fly-Ash Particles on Aluminium Metal Matrix Composite

2021 ◽  
Vol 106 ◽  
pp. 26-30
Author(s):  
C. Thirupathaiah ◽  
Sanjeev Reddy K. Hudgikar
Keyword(s):  
Silicon Carbide ◽  
Tensile Strength ◽  
Composite Material ◽  
Fly Ash ◽  
Boron Carbide ◽  
Base Material ◽  
Stir Casting ◽  
Pure Aluminium ◽  
Weight Percentage ◽  
Percentage Ratio

The current paper deals about the fabrication of composite material is to combine the desirable attributes of metals and ceramics. Aluminium 6063 used as a base material in combination with the Silicon carbide ,Boron carbide and fly-ash were used as reinforcement material. Our intention is to increased or enhanced properties of pure Aluminium 6063 by addition of Silicon Carbide ,Boron Carbide and fly-ash. The process of fabrication composite material is prepared by using stir casting method. In this paper, addition of Silicon Carbide 1% , Boron Carbide 1% and fly-ash1% with aluminium increasing percentage ratio the mechanical properties of composite material is enhanced, so it is clear that the effect of Silicon Carbide , Boron Carbide and fly-ash were helpful to increasing properties of pure Aluminium by addition. The influence of reinforced ratio of silicon carbide, Boron carbide and fly-ash particles on mechanical behavior was examined. The effect of different weight percentage of silicon carbide, Boron carbide and fly-ash in composite on tensile strength, hardness, microstructure was studied. It was observed that the hardness & tensile strength of the composites increased with increasing reinforcement elements addition in it. The distribution of silicon carbide, Boron carbide and fly-ash particles was uniform in aluminum.

Corrosion Behaviors for Galvanizing, Galvalume and Chromate Treated Steels in 1% NaOH Solution

2017 ◽  
Vol 744 ◽  
pp. 217-222 ◽  
Author(s):  
Kyung Man Moon ◽  
Sung Yul Lee ◽  
Jae Hyun Jeong ◽  
Myeong Hoon Lee
Keyword(s):  
Corrosion Resistance ◽  
Rapid Development ◽  
Steel Structures ◽  
Galvanized Steel ◽  
Localized Corrosion ◽  
Industrial Society ◽  
General Corrosion ◽  
Naoh Solution ◽  
Corrosive Environments ◽  
Chromate Treatment

The galvanized steel structures may be inevitably corroded rapidly in the case of exposed to corrosive environments for long time, and these corrosive environments has been accelerated with increasing the environmental contamination due to the rapid development of industrial society. However, since the galvanizing method have the various merits compared to surface coating treatment in economical point of view, the galvanized steel have been extensively used to the numerous constructional steels such as a guard rail of high way, various types of structural steel for manufacturing ship and various industrial fields etc.. Therefore, it has been made an effort to improve the corrosion resistance of the galvanizing film through various methods such as variation of chemical composition of galvanizing bath, chromate treatment and coating treatment etc.. In this study, comparison evaluation on the corrosion resistance of three types of the test specimens, that is, three samples of pure galvanizing, galvalume and chromate treatment were investigated using electrochemical methods in 1% NaOH solution. The samples of chromate treatment and of galvalume exhibited the lowest and highest corrosion current density respectively in 1% NaOHsolution. In addition, the sample of chromate treatment revealed the highest impedance at 0.01Hz, which is considered that the oxide film by chromate treatment is deposited on the surface of pure galvanizing sample. After drawing polarization curves, the corroded surface of the pure galvanizing specimen indicated pattern like as localized corrosion, moreover, the large amount of corrosive products was observed on the surface of galvalume sample. However, the smooth pattern nearly similar to general corrosion was observed at the corroded surface of the sample of chromate treatment. Consequently, it is considered that the chromate treatment is an optimum method compared to pure galvanizing and, galvalume treatment to improve corrosion resistance in 1% NaOH solution.

scholarly journals Comparative Analysis of the Corrosion Resistance of Titanium Alloys Intended to Come into Direct or Prolonged Contact with Live Tissues

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2841 ◽  
Author(s):  
Florina Ionescu ◽  
Lucien Reclaru ◽  
Lavinia Cosmina Ardelean ◽  
Andreas Blatter
Keyword(s):  
Corrosion Resistance ◽  
Inductively Coupled Plasma ◽  
Surface Oxidation ◽  
Melting Process ◽  
Open Circuit ◽  
Localized Corrosion ◽  
General Corrosion ◽  
Electrochemical Tests ◽  
Inductively Coupled ◽  
Prolonged Contact

The evaluation of the biological safety and degradation of materials is quite important for risk assessment in various biomedical applications. In this study, two procedures were followed to characterize the corrosion resistance of different Ti-based alloys. The first one consisted of performing specific electrochemical tests (open circuit potential, linear resistance polarization, Tafel plots, potentiodynamic polarization) in order to highlight their behavior to the general and localized corrosion. The static and dynamic fatigue cycles combined with crevice corrosion conducted on a new prototype have completed the study. The second procedure followed was a cations extraction investigation (by inductively coupled plasma mass spectrometry) in order to verify the ionic permeability of the oxides layers formed on the surfaces. Optical and scanning electron microscopy were used for surface analysis. It was noticed that in these two electrolytes, the bulk Ti-based alloys presented an almost similar general corrosion behavior. The small differences of behavior for Ti6Al4V scaffolds were correlated to the surface oxidation and roughness (owing to the selective laser melting process). The Ti alloys presented no traces of localized corrosion at the end of the test. The fatigue cycles revealed that a strong and adhesive oxides film was formed during the static cycles (difficult to remove even during the depassivation steps). The concentration of cations released was at the detection limit, revealing very good passivation films, in adequacy with the all the other results.

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