Nano-wear-induced behavior of selective laser melting commercial pure titanium

In this work, the nano-wear-induced behavior of selective laser melting (SLM) processed commercial pure titanium was investigated under several applied loads from 1 mN to 100 mN. The dense (over 99%) commercial pure titanium sample was manufactured using SLM process with optimized process parameters (900 J m-1). Nano-wear testing was performed on the polished surface of SLM processed commercial pure titanium. The friction coefficient increased from 0.04 to 0.9 as the load increased from 1 mN to 100 mN. Additionally, the sliding behavior changed along with the applied loads, from elastic to plastic and unstable friction behaviors. The elastic-plastic transition appeared at applied load of 50 mN, which was also confirmed by the calculation results. While the applied load ranged between 50 mN and 80 mN (plastic friction), the average friction coefficient was light smaller than that of the macroscopic ball-on-disc test. During the sliding, a friction vibration appeared and its mechanism was also investigated and discussed combine the wear surface morphologies.