FY07 LDRD Final Report A Fracture Mechanics and Tribology Approach to Understanding Subsurface Damage on Fused Silica during Grinding and Polishing (open access)

FY07 LDRD Final Report A Fracture Mechanics and Tribology Approach to Understanding Subsurface Damage on Fused Silica during Grinding and Polishing

The objective of this work is to develop a solid scientific understanding of the creation and characteristics of surface fractures formed during the grinding and polishing of brittle materials, specifically glass. In this study, we have experimentally characterized the morphology, number density, and depth distribution of various surface cracks as a function of various grinding and polishing processes (blanchard, fixed abrasive grinding, loose abrasive, pitch polishing and pad polishing). Also, the effects of load, abrasive particle (size, distribution, foreign particles, geometry, velocity), and lap material (pitch, pad) were examined. The resulting data were evaluated in terms of indentation fracture mechanics and tribological interactions (science of interacting surfaces) leading to several models to explain crack distribution behavior of ground surfaces and to explain the characteristics of scratches formed during polishing. This project has greatly advanced the scientific knowledge of microscopic mechanical damage occurring during grinding and polishing and has been of general interest. This knowledge-base has also enabled the design and optimization of surface finishing processes to create optical surfaces with far superior laser damage resistance. There are five major areas of scientific progress as a result of this LDRD. They are listed in Figure 1 and described briefly in this …
Date: February 5, 2008
Creator: Suratwala, T I; Miller, P E; Menapace, J A; Wong, L L; Steele, R A; Feit, M D et al.
System: The UNT Digital Library
Homeland Security Department: FY2007 Appropriations (open access)

Homeland Security Department: FY2007 Appropriations

This report is a guide to one of the regular appropriations bills that Congress considers each year.
Date: July 5, 2006
Creator: Lake, Jennifer E.; Nuñez-Neto, Blas; Lister, Sarah A.; Masse, Todd; Wasem, Ruth E.; Bea, Keith et al.
System: The UNT Digital Library