Effect of grain size on the micro-tribological behavior of pure titanium processed by high-pressure torsion

► Grain size of pure Ti was reduced to ∼130 nm from ∼8.6 μm using high pressure torsion (HPT). ► Microhardness was improved from 182 HV1 to 305 HV1. ► Micro wear behavior of HPT processed Ti was studied for the first time. ► Wear of coarse grained Ti was dominated by ploughing and wedge forming, while wear of HPT processed Ti was dominated by abrasion. ► HPT processed Ti has more homogeneous wear scar and lower wear rate.