The development of advanced technology at this time requires good quality
materials, especially those made from metal. Mechanical properties of metal
materials such as: hardness, strength, ductility, and wear resistance which always
relates to the composition and microstructure of the material. This development
encourges the need of the metal composition and microstructure in research an
tecnology. The objective of the study is to investigate the influence of the
composition ratio of N
2
and CH
4
gases (1:1, 1:2, 1:3, and 1:4) to composition,
microstructure, hardness, and wear rate at commercially pure titanium surface. In
this study, duration process, temperature, and pressure are maintened constant at 4
hours, 450
o
C, and 1,6 mBar, respectivelly. The result shows that the hardness
increased from 105,75 VHN to 236,32 VHN. The optimum hardness occurred
under plasma nitrocarburizing at temperature of 450
o
C, pressure of 1,6 mBar, and
duration time of 4 hours. Meanwhile, wear rate decreased from 4,0148 × 10
-8
mm
2
/ kg to 6,140 × 10
−9
mm
2
/ kg. The increased hardness and the decreased wear rate
occurred because TiN and TiC compounds was formed at the surface of
commercially pure titanium
Keyword : Plasma, Nitrocarburizing, Titanium, Composition
