MS Thesis Defense by Rick Kalil
Friday, May 21, 2004

( Dr. Shreyes N. Melkote, Chair)

"Evaluation of Frictional Characteristics of Precision Machined Surfaces"

Abstract

Precision surface finishes are used in a wide variety of applications. From bearing races and rolling elements to parallel slide ways, the frictional characteristics of these surfaces are critical to the performance of the products. Experimental trial and error has shown that certain surfaces outperform others in certain applications, but the specific surface characteristics that make this true have yet to be fully understood. The research goal is to develop an apparatus that can test the coefficient of rolling and/or sliding friction of different precision machined surfaces and to combine this data with topographic analysis of the surfaces to create a model that relates the surface texture to the frictional performance of a surface.


The sample treatments will consist of four different surface textures (hard-turned, ground, honed and isotropic finish) and four different relative
surface speeds. By monitoring the torque in the sample mounting shaft under lubricated conditions the coefficient of rolling/sliding friction of each
surface will be found. Utilizing white light interferometry measurement of the surfaces, a highly detailed map of each surface will be obtained. Using
different characteristic values of each machined surface (RMS roughness, asperity density, lay direction, etc.), the frictional behavior of the
surfaces will be compared to the surface characteristics yielding insight into the relationship between surface finish and friction in rolling/sliding
contact.