Effect of severe plastic deformation by ECAP on corrosion behaviour of aluminium alloy AA 7075
Journal Title: Archives of Materials Science and Engineering - Year 2016, Vol 81, Issue 2
Abstract
Purpose: The present study compares the corrosion behaviour of overaged AA 7075 before and after equal channel angular pressing ECAP in two media, containing chlorides, in order to answer the question how grain refinement of aluminium alloys influences their corrosion properties.Design/methodology/approach: The effect of equal channel angular pressing ECAP on corrosion behaviour of aluminium alloy AA 7075 was studied in two water solutions, containing chloride ions: 1) 0.01 M Na2SO4 with addition of 0.01%Cl-, and 2) 3g/l H2O2 and 57g/l NaCl. The changes in electrochemical characteristics, provoked by grain size refinement after equal channel angular pressing ECAP, were found using potentiodynamic polarisation. Steady state potential, corrosion potential, corrosion current density; breakdown (pitting) potential of overaged and deformed by equal channel angular pressing ECAP aluminium alloy AA 7075 were measured.Findings: In the environment with lower chloride concentration equal channel angular pressing ECAP process led to increase in pitting corrosion resistance and in the medium with higher chloride concentration - to decrease in pitting corrosion resistance. That way grain refinement does not demonstrate a uni-directional influence on corrosion resistance of AA 70775.Research limitations/implications: The results suggest the possibility for development of materials having the same chemical composition but with different corrosion resistance to different environments.Originality/value: The paper presents the corrosion behaviour of ultrafine-grained aluminium alloy AA 7075 and the influence of the chloride ions concentration in the corrosion medium on this behaviour.
Authors and Affiliations
M. Ilieva, R. Radev
Keywords
Related Articles
- EP ID EP189894
- DOI 10.5604/01.3001.0009.7099
- Views 89
- Downloads 0
Temperature changes influenced by different types of light curing units during polymerization of resin-based dental composite materials
Purpose: of this study was to evaluate the influence of LCU type on temperature changesduring polymerization of two resin-based composites with different matrices (silorane-basedand methacrylate-based).Design/methodology...
Combined effects of strain and cooling path on hot deformation response and microstructure of low-carbon structural steel
Purpose: The aim of the paper is to analyse the effect of thermomechanical process with different cooling paths on microstructure and mechanical properties of low-carbon structural steel. Design/methodology/approach: The...
Use of machine learning algorithm for the better prediction of SR peculiarities of WEDM of Nimonic-90 superalloy
Purpose: With the end goal to fulfil stringent structural shape of the component in aeronautics industry, machining of Nimonic-90 super alloy turns out to be exceptionally troublesome and costly by customary procedures,...
Abrasion resistance of Ni-B/Si3N4 composite layers produced by electroless method
Purpose: The paper presents the results of investigations of Ni-B/Si3N4 composite layers produced on steel substrate by electroless method. Design/methodology/approach: Amorphous silicon nitride powder (Si3N4) with nanom...
Application of polymer impression masses for the obtaining of dental working models for the stereolithographic 3D printing
Purpose: The aim of the work is to execute measurements of digital dental models taken by scanning prosthetic impressions using the engineering CAD software and finding dimensional differences and scale factor for precis...