1. 2010 MoSAIc cohort www.me.iastate.edu/mosaic ISU ME REU 1 Thin Film Composite for Friction and Wear Analysis Jack Stransky Dr. Sriram Sundararajan Chris Tourek

2. 2010 MoSAIc cohort www.me.iastate.edu/mosaic ISU ME REU 2 Outline Motivation and objectives Sputter Deposition Tribometry Current Status Film Deposition Film thickness measurements – Profilimetry Timeline

3. 2010 MoSAIc cohort www.me.iastate.edu/mosaic ISU ME REU 3 Motivation and objectives Motivation: to create a thin film composite material which has the best physical properties of its constituents. This coating will be compared to the single material coatings by friction and wear analysis. Objective: Create thin film composites using sputter deposition. Materials to be used are: Tungsten disulfide – Solid state lubricant, high melting point (1250 C) Titanium nitride – Extremely hard, protective material Source: wikipedia.org

4. 2010 MoSAIc cohort www.me.iastate.edu/mosaic ISU ME REU 4 Sputter Coating Free e - from electrode are accelerated at Ar atoms, driving e - off Ar, forming Ar + ions Source: http://www.ajaint.com/whatis.htm

5. 2010 MoSAIc cohort www.me.iastate.edu/mosaic ISU ME REU 5 Sputter Coating Ar + ions are accelerated into negatively charged electrode, blasting target material loose Source: http://www.ajaint.com/whatis.htm

6. 2010 MoSAIc cohort www.me.iastate.edu/mosaic ISU ME REU 6 Sputter Coating Free e - recombine with Ar – ions, causing release of photons causing the glow of the plasma Source: http://www.ajaint.com/whatis.htm

7. 2010 MoSAIc cohort www.me.iastate.edu/mosaic ISU ME REU 7 Tribometer Friction and wear analysis Friction is determined by applying normal load and comparing this to the lateral force on the sample. The slope between these is the coefficient of friction. Wear is determined by applying a normal force back and forth against the sample and determining the amount of material that has been worn away using profilometry or AFM

8. 2010 MoSAIc cohort www.me.iastate.edu/mosaic ISU ME REU 8 Current status Depositing, analyzing, and optimizing properties of films of pure WS 2 and TiN Using AFM and Profilometer to determine film thickness Too much dispersion in samples to obtain accurate film thickness, new samples will be deposited using a method to reduce dispersion between glass and film to better analyize thickness

9. 2010 MoSAIc cohort www.me.iastate.edu/mosaic ISU ME REU 9 Profilometer Average = 276.8 nmStandard deviationSurface roughness Ra 276.8 nm86.3 nm56.9 nm

10. 2010 MoSAIc cohort www.me.iastate.edu/mosaic ISU ME REU 10 Timeline This Week Deposit and analyze better WS2 coatings Begin TiN coatings Week of July 19 th Deposit and Analyze TiN coatings Begin composite film deposition Week of July 26th Begin frictional tests of coatings Week of August 2nd Friction and wear testing

11. 2010 MoSAIc cohort www.me.iastate.edu/mosaic ISU ME REU 11 Extra: AFM Currently using AFM to determine film thickness

12. 2010 MoSAIc cohort www.me.iastate.edu/mosaic ISU ME REU 12 Extra: Ra Arithmetic average of absolute values of height deviations from the mean or the average of the peaks and valleys A term used to describe surface roughness L = evaluation length Z(x) = profile height function Source: http://www.harrisonep.com/resources/faq.html#ra