Understanding crystallographic orientation dependent dissolution rates of 90Cu-10Ni alloy: New insights based on AFM/SKPFM measurements and coordination number/electronic structure calculations

摘要

The purpose of this paper is to provide a new understanding of the anisotropic corrosion behavior of 90Cu-10Ni alloy. A clear correlation between grain orientations, SKPFM derived work functions (WF), and dissolution rate is demonstrated. Grains close to (100) exhibited lower WF with lower dissolution rate, whereas grains close to (111) with higher WF dissolved faster. A surface step dissolution model is proposed for faster dissolution of the closest packed (111) planes. Calculations based on coordination number and the first-principles were performed to evaluate the proposed model. Calculation results correspond well with each other, and supported the experimental results observed.