Corrosion Performance of the Shot-Peened High Strength Cu-alloy CuNi3SiMg in 0.1M NaCl

摘要

The present work was aimed at evaluating the effects of shot peening on corrosion performance of CuNi3SiMg alloy in 0.1M NaCl solution. A combination of rotary swaging and optimized precipitation hardening was applied to generate ultra-fine grained (UFG) microstructure. Shot peening to full coverage (100%) was performed using spherically conditioned cut wire (SCCW 14) with an average shot size of 0.36 mm at Almen intensities of 0.1, 0.17 and 0.25 mmA for solutionized, UFG and precipitation hardening conditions, respectively. After applying this mechanical treatment, the change in the surface and near surface layers was determined by surface roughness and microhardness measurements. Experimental investigations showed that an optimized combination of mechanical surface treatment and precipitation hardening condition reduces the corrosion rate in 0.1M NaCl solution by generating more favorable thermodynamic conditions for more proper formation of passive oxide layer with higher corrosion resistance.