Effects of ternary metal additions on corrosion of spark plasma sintered Ni-Fe alloys in H2SO4 and NaCl

Abstract

Effect of ternary additions on electrochemical behavior of Ni-Fe binary alloys developed by Spark Plasma Sintering (SPS) were investigated and reported. All specimens revealed common passivity behavior in H₂SO₄. Both binary and ternary alloys did not reveal passivity region under saline conditions. The alloys have lower corrosion rates in NaCl than in H₂SO₄. Binary Ni₅₀Fe₅₀ alloy is characterized by large pits in H₂SO₄ and homogeneous corrosion on surface in NaCl. Ni₅₀Fe₄₀Ta₁₀ shows better passivity in 1 M H₂SO₄ and Ni₅₀Fe₄₀Al₁₀ has the lowest corrosion rate in 3.5 wt.% NaCl.

KEY WORDS: Spark plasma sintering, Corrosion, Ni-Fe based alloy, Ternary alloys, Powder metallurgy

Bull. Chem. Soc. Ethiop. 2018, 32(2), 337-349.

DOI: https://dx.doi.org/10.4314/bcse.v32i2.12