1. Wear
   
   1. Wear of Mechanical Systems
      
   2. Wear of nanoComposites
      
2. Friction and Lubrication
   
   1. Granular Lubrication and Wear
      
   2. Gas Surface Interactions
      
3. Biomaterials Tribology
   
   1. Wear of Total Knee Replacements
      
   2. Hydrogels
      

ccurate measurements of wear rates under abrasive conditions such as those experienced by the equipment used in crop harvesting and military equipment operated in arid sandy environments required the development of a new and specialized abrasion tribometer. The goal of this project was to establish the needed technology to quantify the suitability of the existing suite of available coatings and materials for use in agriculture equipment.  The tribometer was developed the Tribology Laboratory at the University of Florida.  Further, limited Finite Element Modeling of the abrasive wear tribometer will be performed with the aim of being able to include this in future computer aided design tools.

The tribometer is capable of monitoring friction coefficient, normal load, and temperature continuously. The wheel material is variable and can be fibrous to mimic the stalk material that entrains the abrasives in harvesting. The open design allows us to introduce water and other fluids to alter the tribochemical conditions.

The Rheological Behavior of Powders

HE FLOW OF granular materials, trapped between two surfaces in motion, has been proposed as a suitable lubrication method for extremely high temperature applications where fluid lubricants are unavailable. It is proposed that the kinetic energy of the particle system and the collisions of particles with the containing surfaces results in both a load carrying normal stress and a tangential shear stress on the surfaces. It has been experimentally shown that glass beads trapped in an annular shear cell apparatus can generate significant load carrying normal stresses. 

There are numerous difficulties in using large granules for lubrication, however fine powders may offer an opportunity to provide lubricous materials to a bearing system.  One of the major difficulties will be transporting these powders to the bearing contact.  We are developing a micro-shear cell Rheometer to investigate the rheological behaviors of cohesive nano-particles with the hope that a better understanding of the rheology of these powders will aide in the development of a powder delivery system. This work is supported by Inhale Therapeutics.

Oxford English Dictionary

Where observation is concerned, chance favors only the prepared mind.

Louis Pasteur