Grain Boundary Characteristics Optimization of 90Cu–10Ni Copper-Nickel Alloy for Improving Corrosion Resistance

Abstract

The grain boundary character distribution and corrosion resistance of a 90% Cu 10% Ni alloy were investigated. When the rolling reduction was increased, the fraction of coincidence site lattice (CSL) grain boundaries with low-Σ index increased initially, and decreased thereafter. The highest fraction of low-Σ CSL boundaries (70%) was obtained through 9% secondary rolling reduction. Electrochemical testing indicated that the corrosion resistance improved significantly after intermediate deformation (7% and 9% reduction ratios) and high-temperature annealing. This improvement was attributed to an increase in the fraction of low-Σ CSL boundaries and the formation of triple junctions during recrystallization.