Influences of 17-4PH Stainless Steel and α + β Titanium Alloy Powders for Corrosion Susceptibility on Friction Stir-Processed AA7075-T651 Aluminium Matrix Composites

O. M. Ikumapayi*, E. T. Akinlabi, J. D. Majumdar, S. A. Akinlabi

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

12 Citations (Scopus)

Abstract

Stainless steel (17-4PH) and α + β titanium alloy (Ti–6Al–2Sn–2Zr–2Mo–2Cr–0.25Si) powders have been known for their high strength with low density as well as promising mechanical properties and remarkable corrosion resistance. In view of this, a comparative performance assessment was carried out to evaluate their percentage inhibition performance efficiencies (%IPEs) on the friction stir-processed 7075-T651 aluminium matrix composites (AMC) reinforced with 17-4PH and Ti–6Al–2Sn–2Zr–2Mo–2Cr–0.25Si powders. The process parameters used were the plunge depth of 0.3 mm, processing speed of 20 mm/min, the tilt angle of 3°, the rotational speed of 1500 rpm and 100% inter-pass overlap with double passes. Corrosion study was carried out in a concentration of 3.5% NaCl medium at an ambient temperature of 25 °C using potentiodynamic polarization technique on AA7075-T651/17-4PH AMC and AA7075-T651/Ti–6Al–2Sn–2Zr–2Mo–2Cr–0.25Si AMC with reference to the processed and unprocessed base metal. It was revealed that the AA7075-T651/Ti–6Al–2Sn–2Zr–2Mo–2Cr–0.25Si AMC has higher %IPE of 98.26%, while AA7075-T651/17-4PH AMC exhibited %IPE of 90.57%. The corrosion rate was extraordinarily reduced from 5.0718 to 0.087675 mm/year using α + β titanium alloy powder as corrosion resistance while that of 17-4PH stainless steel reduced to 0.47744 mm/year. The polarization resistance was greatly high when inhibition α + β titanium alloy powder was used and found to be 2240.7 Ω as against 191.06 Ω when 17-4PH stainless steel was used as a corrosion barrier. The SEM images of the corroded samples revealed the presences of pits and intergranular corrosion attack with the trace of flakes on the surfaces.

Original languageEnglish
Article number98
Pages (from-to)1-11
Number of pages11
JournalJournal of Bio- and Tribo-Corrosion
Volume5
Issue number4
DOIs
Publication statusPublished - 10 Oct 2019
Externally publishedYes

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