Al2O3 Coating on the polished Ti-6Al-4V disks, 16mm diameter, was carried out by HVLTS (High Voltage Low Temperature Sputtering)

The Characterization of the Coating was Performed by the Following Methods:

  • Metallographic Examination
  • EDS analysis on the coated surface
  • HRSEM to reveal surface morphology
  • Nano-hardness measurements
  • Friction coefficient measurements

Figures 1 and 2:

  • The metallographic cross-section of the coated specimen is shown in Figures 1 and 2
Fig 1: The Metallographic Cross-Section of the Coated Sample – Uniform Thickness, Adherent Layer Fig 2: The Same as in Fig 1 at Higher Magnification. The Alumina Coating Thickness 0.6µm

The dense adherent coating with uniform thickness of 0.6µm was observed. No discontinuities at the interface or within the coating were revealed.

EDS Spectrum and Nano-Hardness Measurements:

  • EDS spectrum obtained from the surface revealed Al, O peaks and the substrate contribution of Ti, V peaks.
  • The surface morphology was revealed as featureless by High Resolution SEM examination at up to x200.000 magnification. Nano-hardness measurements with the loading of L=5•10-3N yielded hardness level of ~ 20 GPa
  • The friction experiments on Ti/Al2O3- Ti pair are in processing
Fig 3: Spectrum EDS, Obtained from the Coated Surface Fig 4: The Loading-Unloading Curves of Nano-Indenter. The Measured Hardness- 20 GPa L=5•10-3N

The Other Physical Properties of the Coating are as Follows:

  • Hydrophobic (contact angle 100-103°)
  • Transparency band: γ from 0.3 to 8 µm

Possible Applications:

  • Wear and Corrosion resistant coatings with solid lubricant properties
  • Insulation coatings