Solid Slider Bearings Lubricated by Their Own Melting or Sublimation

We study the steady-state hydrodynamic lubrication of a solid-solid sliding bearing with spontaneous fusion or sublimation of the solid slider substance. Lubrication is sustained by the fluid film produced by fusion or sublimation. Our analysis extends the recent literature on liquid film lubrication of a melting solid slider to the interesting case of gaseous film lubrication of a sublimating solid slider. The results are in the form of analytical expressions showing the explicit influence of every parameter of the problem, together with conditions specifying the range of validity, and conditions guaranteeing that fusion or sublimation develop the necessary supply of lubricant. For substances like water and bismuth that contract upon melting, we extend the results to the interesting range of conditions dominated by the effect of pressure on the melting temperature.