AFM of titanium nitride layers prepared under glow discharge conditions

Hollow cathode plasma nitriding of medical grade Ti6Al4V: A comprehensive study

“…Since the nitrided layer is formed to improve biocompatibility, the electrochemical results showed that such treatment can be performed without worries about the corrosion behavior of the alloy. Similar results have previously been found in the literature 18,77 and this decrease in corrosion properties is attributed to: a) a thin oxide layer formed under the compound layer before HCPN, which rises chemical activity and b) the uneven distribution of nitrogen on the surfaces of plasma-treated samples, which result in uneven corrosion properties. As aforementioned, if corrosion rate is taken as the main decisive factor, it is still under proposed values for metallic implants, with a limit of 1 μm per year.…”

“…This is further confirmed through three-dimensional scanned surfaces, Figure 7, where the micro-grooves and micro-ridges can be seen in detail in Figure 7(d) for HCPN sample. Previous studies showed that the HCPN temperature creates more diffuse grains, which may be due to agglomeration of minor grains and a concealment of polishing lines, 77,78 something not achieved here. Rather, the texturing roughly followed the polishing lines (Figure 7(c) and (d) expounds this effect).…”