Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2018)
    Thin Films Tuesday Sessions
       Session TF-TuE

Paper TF-TuE1
Effects of Ar:N2 gas ratio on TiN and TiAlN Thin Films Synthesized via RF Magnetron Sputtering

Tuesday, December 4, 2018, 5:40 pm, Room Naupaka Salons 4

Session: Next-generation Protective Coatings and Tribological Applications
Presenter: Jason Audrey Licerio, University of the Philippines
Authors: J.P. Licerio, University of the Philippines
A.R. Alibadbad, University of the Philippines
M.R. Vasquez, University of the Philippines
Correspondent: Click to Email
There is a growing interest in using titanium nitride (TiN) and titanium aluminum nitride (TiAlN) as a hard coating in recent years because of their high hardness, low friction coefficient, and good wear and oxidation resistance. Lifetime of machining tools significantly increase when coated with these transition metal nitrides. Radio frequency (RF) magnetron sputtering was used to synthesize the films. In this study, the Ar:N2 ratio of synthesized TiN and TiAlN films were varied and characterized using a single target magnetron. That is, thin film growth is achieved using either a Ti target or 1:1 TiAl composite target. Argon:nitrogen (Ar:N2) partial pressure ratios were varied at 9:1, 8:2, and 7:3 to grow the TiN and TiAlN films. Scanning electron microscope (SEM) images of TiN showed rough, ‘pyramid-like’ grains. Higher N2 content resulted in more compact grains. The TiAlN films formed were dense ‘cauliflower-like’ grains. Cross-sectional SEM images showed both films having columnar structure with increasing grain diameter as N2 content is increased. Energy dispersive x-ray spectroscopy mapping of TiN showed over-stoichiometric TiNx. TiAlN maps showed almost 1:1 Ti:Al ratio but an abundance of N, confirming the formation of TiAlNx films. X-ray diffraction (XRD) results of TiN showed presence of (111), (220), and (311) TiN crystallographic planes. Decreasing N2 content in the system resulted in the increase in intensity of (111) and (220) planes while increase in N2 resulted in broadening of (111) plane. TiAlN XRD results showed formation of (111), (200), and (220) peaks. Increasing N2 enhances the (220) peak. The 80:20 Ar:N2 ratio resulted in increase of (200) peaks. The performance of drill bits coated with TiN showed three-fold increase in number of holes drilled while TiAlN films showed a two-fold increase as compared to that of uncoated drill bits. This work succeeded in the synthesis of TiN and TiAlN films and improving drill bit performance.