I&EC 113 |
| The unique tribo-chemical properties of crystalline diamond and amorphous diamond-like carbon (DLC) have stimulated substantial interests in their application ranging from NEMS/MEMS devices to machining tool coatings. In addition to their low friction and high wear resistance, the anti-sticking property of carbon coatings to the extremely chemical affinitive aluminum has generated interest in using them as coating to reduce adhesion and friction in aluminum alloy forming, machining and being operated under mechanical contacts. Various Al/carbon interfaces have been studied using Density Functional Theory to reveal the bonding nature and the strength at the interfaces. To predict the adhesive transfer, the Al/carbon interfaces were subjected to a series of tensile strain increments up to fracture. It has been found that Al tends to stick to clean diamond surface, but not the chemically passivated interfaces, on the other hand graphite will transfer to Al surface. The effect from testing atmosphere on the friction behavior of DLC against Al can also be explained through different absorption behaviors of gas molecules at the diamond surface modeled by DFT calculations. These results collectively agree with experimental observations and provide deep insight and guidance for the coating design with minimum adhesion to aluminum. |
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Computational Material Design in Chemical Industries, Sponsored by Novel Chemistry with Industrial Applications Sub-Division
1:30 PM-5:00 PM, Monday, 11 September 2006 Moscone Center -- Room 252/254, Oral
Division of Industrial & Engineering Chemistry |