AVS 50th International Symposium
    Advanced Surface Engineering Tuesday Sessions
       Session SE-TuA

Paper SE-TuA2
Synthesis and Characterization of Nanolayered TiO@sub x@/Al@sub 2@O@sub 3@ Coatings for Possible Elevated Temperature Applications

Tuesday, November 4, 2003, 2:20 pm, Room 323

Session: High Temperature Protective Coatings
Presenter: K.W. Lee, Northwestern University
Authors: K.W. Lee, Northwestern University
M. Sturino, Northwestern University
Y.W. Chung, Northwestern University
L.M. Keer, Northwestern University
Correspondent: Click to Email
It was demonstrated from previous studies that nanolayered coatings with the correct choice of components and layer thicknesses have enhanced hardness, due to interfaces providing barriers against dislocation motion and multiplication. We expect superlattice coatings made of two immiscible components to be stable against interdiffusion. Therefore, the layer structure and reasonable hardness for such nanolayered coatings should be preserved at high temperatures. These thermally stable coatings are desirable for protection of cutting tools in dry machining applications, which may operate at temperatures in the 800-1000@super o@C regime or higher. For this reason, TiO@sub 2@ and a-Al@sub 2@O@sub 3@ were chosen for this investigation. Nanolayered coatings made of these two immiscible components were synthesized by dc dual-cathode reactive magnetron sputtering. Substrate rotation was used to enhance uniformity of the coating. Substrates include M2 steel and Si(001). These coatings were exposed to air at 1000@super o@C. Coatings deposited on silicon were characterized before and after the heat treatment in terms of surface roughness, residual stress, and nanoindentation hardness. Actual dry machining will be performed to evaluate the performance of these coatings. These results will be presented and discussed in terms of the coating potential in dry machining and high-temperature tribological applications.