Influence of Plastic Deformation on the Corrosion Behaviour of As-Cast AlMg2 and AlCu4Mg1 Aluminium Alloys in NaCl Solution

The influence of plastic deformation on the corrosion behavior of as-cast AlMg2 and AlCu4Mg1 aluminum alloys was studied at the microscale using the Electrochemical Microcell Technique and surface microgauges. It was shown that large strain gradients develop locally. The corrosion behavior of both alloys was affected by plastic deformation. The most active sites contain large strain gradients in AlMg2 and cracks with damage in the matrix in AlCu4Mg1.

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Investigations on strain distribution, stress-based fracture limit and corrosion behaviour of titanium Grade 2 sheets during single point incremental forming

Anti-Corrosion Methods and Materials ◽

10.1108/acmm-04-2019-2113 ◽

2020 ◽

Vol 67 (1) ◽

pp. 119-127 ◽

Cited By ~ 2

Author(s):

G. Yoganjaneyulu ◽

V.V. Ravikumar ◽

C. Sathiya Narayanan

Keyword(s):

Plastic Deformation ◽

Corrosion Rate ◽

Strain Distribution ◽

Incremental Forming ◽

Corrosion Behaviour ◽

Single Point ◽

Single Point Incremental Forming ◽

Nacl Solution ◽

Content Type ◽

Titanium Grade

Purpose The purpose of this paper is to investigate the strain distribution, stress-based fracture limit and corrosion behaviour of titanium Grade 2 sheets during single point incremental forming (SPIF) process, with various computerized numerical control (CNC) spindle rotational speeds and step depths. The development of corrosion pits in 3.5 (%) NaCl solution has also been studied during the SPIF process. Design/methodology/approach A potentiodynamic polarization (PDP) study was performed to investigate the corrosion behaviour of titanium Grade 2 deformed samples, with various spindle rotational speeds in 3.5 (%) NaCl solution. The scanning electron microscope (SEM) and transmission electron microscope (TEM) analysis was carried out to study the fracture behaviour, dislocation densities and corrosion morphology of deformed samples. Findings The titanium Grade 2 sheets exhibited better strain distribution, fracture limit and corrosion resistance by increasing the CNC spindle rotational speeds, tool diameters and vertical step depths (VSD). It was recorded that varying the spindle speed affected plastic deformation which in turn affected corrosion rate. Research limitations/implications In this study, poor corrosion rate was observed for the as-received condition, and better corrosion rate was achieved at maximum speed of 600 rpm and 0.6 mm of VSD in the deformed sheet. This indicates that corrosion rate improved with increase in the plastic deformation. The EDS analysis report of corroded surface revealed the composition to be mainly of titanium and oxides. Practical implications This study discusses the strain distribution, stress-based fracture limit and corrosion behaviour by using titanium Grade 2 sheets during SPIF process. Social implications This study is useful in the field of automobile and industrial applications. Originality/value With an increase in the spindle rotational speeds and VSD, the titanium Grade 2 sheets showed better strain distribution, fracture limit and corrosion behaviour; the same is evidenced in fracture limit curve and PDP curves.

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Corrosion Behavior of Mg-Al/TiC Composites in NaCl Solution

International Journal of Corrosion ◽

10.1155/2011/896845 ◽

2011 ◽

Vol 2011 ◽

pp. 1-7 ◽

Cited By ~ 14

Author(s):

L. A. Falcon ◽

E. Bedolla B. ◽

J. Lemus ◽

C. Leon ◽

I. Rosales ◽

...

Keyword(s):

Corrosion Rate ◽

Corrosion Behavior ◽

Electrochemical Impedance ◽

Base Alloy ◽

Electrochemical Techniques ◽

Al Alloy ◽

Nacl Solution ◽

The Matrix ◽

Diffusion Phenomena ◽

Lower Corrosion Rate

The corrosion behavior of TiC particles reinforced Mg-Al alloy in 3.5% NaCl solution has been evaluated using electrochemical techniques. Tested alloys included an Mg-9Al (Mg AZ91E) alloy with and without 56 wt. % TiC particles. Electrochemical techniques included potentiodynamic polarization curves, linear polarization resistance, electrochemical noise, and electrochemical impedance spectroscopy measurements. All techniques showed that the composite exhibited a lower corrosion rate than the base alloy. Evidence of galvanic effects that increased the composite corrosion rate was found between the matrix and the TiC particles. Additionally, the tendency to suffer from pitting corrosion was higher for the base alloy than that for the composite. Electrochemical impedance results showed the importance of adsorption/diffusion phenomena in both materials.

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Evaluation of Corrosion Behaviour for Aluminium Alloy 7075 in 5% NaCl Solution under Slightly Varying Temperature

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.984-985.557 ◽

2014 ◽

Vol 984-985 ◽

pp. 557-563

Author(s):

D.S. Manoj Abraham ◽

H. Kanagasabapathy ◽

Richu John ◽

Muthu Yasar ◽

Shobin Paul

Keyword(s):

Corrosion Resistance ◽

Aluminium Alloy ◽

Corrosion Behavior ◽

Low Temperatures ◽

Penetration Rate ◽

Corrosion Behaviour ◽

Nacl Solution ◽

Small Temperature ◽

Temperature Changes ◽

Logarithmic Law

The main focus of this work is to study and evaluate the corrosion behavior of aluminium alloy 7075 under slightly varying temperature conditions. The corrosion behavior was found out using the Salt Mist test. Aluminium alloy 7075 possesses better corrosion resistance, so it is important to foresee the corrosion behavior of this alloy for varied applications. The Corrosion Penetration Rate was evaluated for the small temperature changes and the results show that the penetration rate increases as temperature increases gradually along with the time for which the specimens are tested. The final result is that aluminium alloy 7075 follows logarithmic law of corrosion at low temperatures.

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EVALUATION OF PITTING CORROSION OF THE SiCP/5A06 ALUMINUM METAL COMPOSITE IN 3.5% NaCl SOLUTION BY MEANS OF ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY (EIS)

International Journal of Modern Physics B ◽

10.1142/s0217979209061160 ◽

2009 ◽

Vol 23 (06n07) ◽

pp. 1497-1502 ◽

Cited By ~ 4

Author(s):

IRFAN AZIZ ◽

QI ZHANG

Keyword(s):

Electrochemical Impedance Spectroscopy ◽

Impedance Spectroscopy ◽

Corrosion Behavior ◽

Electrochemical Impedance ◽

Matrix Alloy ◽

Metal Composite ◽

Nacl Solution ◽

Composite Surface ◽

Pitting Potential ◽

The Matrix

The corrosion behavior of the silicon carbide particulates (17.5 vol.%) reinforced 5A06 aluminum alloy metal matrix composite (MMC) and the 5A06 aluminum matrix alloy has been studied in 3.5% NaCl solution at 35°C by using electrochemical impedance spectroscopy (EIS). Analysis of the results, which were obtained from optical (OM) and scanning electron microscopy (SEM) attached with energy dispersion spectroscopy (EDS), indicate that the corrosion behavior of the materials studied was mainly localized corrosion due to the presence of intermetallics ( Al ( Mn , Fe ), Al ( Si , Mg )) on the surface and crevices at the interface of SiCp/matrix . More numerous, wider spread, smaller and shallower pits were noted on the composite surface relative to the unreinforced matrix alloy during immersion. However, the pitting morphology on both materials was completely different from crystallographic type of pitting. Crystallographic pitting occurred by anodically polarizing the materials above the pitting potential. Further, the occurrence of an inductive time constant at lower frequencies region and the lower impedance as compared to that of the matrix alloy indicate that the corrosion extent of the composite was more severe than that of the matrix alloy, both materials were immersed for varied periods. Two different equivalent circuits were proposed and applied to analyze the EIS measurements, which can simulate the impedance of the composite and the matrix alloy under corrosive environment.

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Effect of Sealing Treatments on the Corrosion Behavior of Micro-arc Oxidation Coating on Aluminum Alloy in Acid NaCl Solution

Journal of Inorganic Materials ◽

10.15541/jim20140582 ◽

2015 ◽

Vol 30 (6) ◽

pp. 627

Author(s):

YE Zuo-Yan ◽

LIU Dao-Xin ◽

LI Chong-Yang ◽

ZHANG Xiao-Hua ◽

ZANG Xiao-Ming ◽

...

Keyword(s):

Aluminum Alloy ◽

Corrosion Behavior ◽

Nacl Solution ◽

Micro Arc Oxidation

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Studies and Research on the Corrosion Behavior of Ni-Al2O3 Compound Coatings Obtained by Electrochemical Methods

The Annals of “Dunarea de Jos” University of Galati. Fascicle IX, Metallurgy and Materials Science ◽

10.35219/mms.2020.3.04 ◽

2020 ◽

Vol 43 (3) ◽

pp. 21-25

Author(s):

Simona BOICIUC ◽

◽

Keyword(s):

Corrosion Resistance ◽

Corrosion Behavior ◽

Corrosion Behaviour ◽

Composite Coatings ◽

Point Of View ◽

Electrochemical Methods ◽

Dispersed Phase ◽

Nickel Matrix ◽

Technical Alumina ◽

Compound Coatings

The undertaken research which is described in this paper aims at the corrosion behaviour of composite coatings in nickel matrix using as dispersed phase technical alumina with dimensions of 5 μm and their characterization from a microstructural point of view. The corrosion resistance in the saline fog of the coatings is influenced by the microstructure, the stresses developed in the layer and the roughness.

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Microstructural Design of an AlMgSi Alloy via ECAP Processing: An Advanced SPD Manufacturing Technique for NC/UFG Materials

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1114.143 ◽

2015 ◽

Vol 1114 ◽

pp. 143-148

Author(s):

Nicolae Serban ◽

Doina Răducanu ◽

Vasile Danut Cojocaru ◽

Nicolae Ghiban

Keyword(s):

Plastic Deformation ◽

Severe Plastic Deformation ◽

Grain Refinement ◽

Shape Change ◽

Large Strain ◽

Metallographic Analysis ◽

Cross Sectional ◽

Ecap Processing ◽

Microstructural Design ◽

Almgsi Alloy

Severe plastic deformation (SPD) has received enormous interest over the last two decades as a method capable of producing fully dense and bulk ultra-fine grained (UFG) and nanocrystalline (NC) materials. Significant grain refinement obtained by SPD leads to improvement of mechanical, microstructural and physical properties. Compared to classical deformation processes, the big advantage of SPD manufacturing techniques, represented in particular by equal channel angular pressing (ECAP) is the lack of shape-change deformation and the consequent possibility to impart extremely large strain. In ECAP processing, the workpiece is pressed through a die in which two channels of equal cross-section intersect at an angle of ϕ and an additional angle of ψ define the arc of curvature at the outer point of intersection of the two channels. As a result of pressing, the sample theoretically deforms by simple shear and retains the same cross-sectional area to allow repeated pressings for several cycles. A commercial AlMgSi alloy was investigated in our study. The specimens were processed at room temperature for multiple passes, using three different ECAP dies. All samples (ECAP processed and as-received) were subjected to metallographic analysis and mechanical testing. Several correlations between the main processing parameters and the resulting microstructural aspect and mechanical features for the processed material were established. It was shown that severe plastic deformation by means of ECAP processing can be used in aluminum alloys microstructural design as an advanced tool for grain refinement in order to attain the desired microstructure and mechanical properties.

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