Effect of Heat Treatment on the Corrosion Behaviour of Rapidly Solidified Al-8Ni-2Co Alloy in NaCl Solution.(Dept.M)

Fawzy El-Sabbahy,R Ramadan,M Kussem

doi:10.21608/bfemu.2021.160683

Fawzy El-Sabbahy, R Ramadan + Show 1 more

Open Access

https://doi.org/10.21608/bfemu.2021.160683

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Abstract

The corrosion behaviour of as-rapidly solidified and heat treated AI 8Ni-2Co alloy ribbons produced using melt spinning technique was investigated. The decomposition behaviour of the rapidly solidified ribbons was followed up using x-ray diffraction, differentialscanningcalometry. microhardness, and metallography. The stable phases which are generally formed in conventional solidified alloy in the as cast condition, were not detected in the as-rapidly solidified specimens. Instead, super-saturated solid solution α-AI was present in addition to fine dispersoids of A19(CoNi)2. The corrosion behaviour was investigated through potentiostatic technique in 3.5% NaCL aqueons solution. The corrosion rate was the lowest in the as-rapidly solidified condition and increased with increasing the annealing temperature as a result of the formation and coarsening of the intermetallic Al3Ni.

Highlights

Introduction: it is generally agreed that aluminium alloys acquire good corrosio.. resistance to. marine environments. many are susceptible to localized corrosion [1,2,3]
Micro-constituents are usually the source of most problems with electrochemical corrosion as they lead to localized attack resulting from the potential difference between the microconstituents and the aluminium matrix
Rapid solidification extends the solid solubility with a consequent homogeneolls distribution of dispersoids in addition to the tonnation of microcrystalline alloys

Summary

Introduction

It is generally agreed that aluminium alloys acquire good corrosio.. resistance to. marine environments. many are susceptible to localized corrosion [1,2,3]. Micro-constituents are usually the source of most problems with electrochemical corrosion as they lead to localized attack resulting from the potential difference between the microconstituents and the aluminium matrix. A solid solution IS the most corrosion resistance form in which an alloy may exist.

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