Effect of plasma nitrocarburizing process on surface hardness and surface roughness of commercially pure titanium.

Plasma nitrocarburizing is a surface hardening method by depositing nitrogen ions and carbon ions on the material's surface to form a hard nitride and carbide phase. This research was aimed to determine the plasma nitrocarburizing's effect on the surface hardness and surface roughness of commercially pure titanium. Phases present in untreated commercially pure titanium were observed with an optical microscope. Then the plasma nitrocarburizing process was performed on commercially pure titanium at an elevated temperature of 450 ^oC and process duration 4 hours. Surface hardness on untreated and plasma nitrocarburized commercially pure titanium was tested with a micro-Vickers tester. Meanwhile, the surface roughness test was carried out before and after the plasma nitrocarburizing process. The thickness of the thin film was observed with a Scanning Electron Microscope. X-Ray Diffraction Testing was applied to determine the compounds formed on a thin layer. Metallographic testing with an optical microscope showed that the material had only phases α. A thin layer thickness of 1.88 µm was observed with a Scanning Electron Microscope. This thin layer was known to be formed from titanium nitride (TiN) and titanium carbide (TiC) compounds based on the results of X-Ray Diffraction testing. The surface hardness of untreated and plasma nitrocarburized were 105.75 VHN and 312.68 VHN, respectively. The surface roughness of untreated and plasma nitrocarburized were 0.11 R_a and 0.13 R_a, respectively. According to the findings of this study, the plasma nitrocarburizing process increased the surface hardness and surface roughness of commercially pure titanium. [ABSTRACT FROM AUTHOR]