Corrosion behavior of pure titanium processed by rotary-die ECAP

The potential of rotary-die equal channel angular pressing (RD-ECAP) for improving the corrosion performance of commercially pure titanium (CP-Ti) in a 3.5% NaCl solution was studied. The microstructure and texture of CP-Ti were evaluated and linked to the corrosion performance. The results showed that as the number of RD-ECAP passes increased, the grains became more refined. A linear correlation of the corrosion current density and grain size was revealed. In addition, strong basal texture was formed after one pass of RD-ECAP, and the texture coefficient remained basically constant with increase in the number of passes. The 4-pass RD-ECAP processed samples with the smallest grain size and strong basal texture exhibited the best corrosion behavior.