ULTRATHIN LIQUID LUBRICATION OF MAGNETIC HEAD-RIGID DISK INTERFACE FOR NEAR-CONTACT RECORDING .2. SHEAR THINNING AND THERMAL THINNING

The Carreau shear thinning equation and the modified Roelands thermal thinning equation are combined by using the generalized master curve a pproach to construct a new thermal non-Newtonian rheology model. The N ewton-Raphson method is then used to curve-fit existing experimental d ata for two perfluoropolyethers to this new model. The thermophysical properties thus found are then used to calculate thermal and shear thi nning correction factors for the ultrathin liquid lubrication of magne tic head-rigid disk interfaces. The results of rheology modeling show excellent fits of the widely ranging raw data with the new thermal non -Newtonian model. The results of hydrodynamic analysis indicate that t he friction force-isothermal Newtonian shear stress curve for these in terfaces is simply a lubricant characteristic curve of thermal-shear t hinning.