Date of Graduation

5-2008

Document Type

Thesis

Degree Name

Bachelor of Science in Mechanical Engineering

Degree Level

Undergraduate

Department

Mechanical Engineering

Advisor

Gordon, Matthew H.

Abstract

Alpha-phase aluminum oxide thin films were created using an Isoflux ICM-10 dual target inverted cylindrical magnetron sputtering system using mid-frequency AC power supplies. Alpha alumina films were deposited at a magnetron power of 6 kW, 50% oxygen partial pressure by volume, and -35 V DC bias. Film thickness, substrate material, and position and orientation within the deposition chamber were varied. To ensure the deposition conditions are suitable for alloys, the substrate temperature was measured using temperature indicating liquids. The experimental results, supported by Explicit Euler numerical analysis, revealed a steady state temperature of ~480°C at 6kW. Transmission electron microscopy (TEM) was used to study alumina films deposited on stainless steel with and without an alpha-phase chromium oxide template layer. The selected area electron diffraction (SAED) patterns indicate that, for both cases, the films tend be predominately alpha-phase with discernable gamma-phase components. Alpha alumina thin films were deposited on titanium to assess their viability as corrosion and wear resistant biomedical implants. Corrosion resistance tests indicated that the coated titanium had improved performance and stability compared to the uncoated titanium. However, the coefficient of friction increased with the applied film. Films were deposited on surgical stainless steel substrates to investigate the adsorption of a model protein (BSA, bovine serum albumin). Results indicate that there was a 50% reduction in protein adsorption for samples with the alumina coating compared to those with no coating.

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