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A Recommendation for an Inspection Standard to Control Sub-Surface Damage in Single-Crystal Sapphire Components

Published

Author(s)

Robert S. Polvani

Abstract

A variety of characterization techniques have been investigated to study surface and subsurface damage in single-crystal sapphire. To characterize the damage in ground surfaces we found that dimpling was the most useful tool. Surfaces with damage intermediate between that of ground surfaces and optically polished (specular) surfaces need to be addressed on a case by case basis. For optically polished surfaces an inspection protocol has been established consisting of optical characterization by bright light inspection, optical microscopy and surface finish measurements and x ray inspection using diffraction topography. A correlation was found between the microstructure imaged in topographs from a series of MOR bars and their fracture strength. Residual damage from the fabrication process reduced the average strength of the bars by 30%.
Citation
A Recommendation for an Inspection Standard to Control Sub-Surface Damage in Single-Crystal Sapphire Components

Keywords

microscopy, microstructure, sapphire, surface damage, surface finish, x-ray topography

Citation

Polvani, R. (2000), A Recommendation for an Inspection Standard to Control Sub-Surface Damage in Single-Crystal Sapphire Components, A Recommendation for an Inspection Standard to Control Sub-Surface Damage in Single-Crystal Sapphire Components (Accessed April 23, 2024)
Created January 1, 2000, Updated February 19, 2017