Layered Atomic Structures of Double Oxides for Low Shear Strength at High Temperatures
Double oxide phases combining a transition metal and a noble metal have recently become a subject of investigation as solid lubricant materials for high-temperature tribological applications. Here, we study the changes in chemistry and crystal structure of silver molybdate (Ag2Mo2O7) and silver tungstate (Ag2WO4) thin films and powders from 25 to 600 °C. We show, using ab initio molecular dynamics, high-temperature X-ray diffraction, high-temperature Raman spectroscopy and differential scanning calorimetry in combination with sliding tests, that the layered atomic structure of silver molybdate facilitates sliding, resulting in a low coefficient of friction (<0.2) from 300 to 500 °C.
Copyright © 2010, Elsevier
Stone, D'Arcy S.; Liu, Jia; Singh, Dinesh P.; Muratore, Christopher; Voevodin, Andrey A.; Mishra, Sanjay; Rebholz, Claus; Ge, Qingfeng; and Aouadi, Samir M., "Layered Atomic Structures of Double Oxides for Low Shear Strength at High Temperatures" (2010). Chemical and Materials Engineering Faculty Publications. 140.