Accession Number : AD0741810

Title :   Polariscopic Characterization of Sapphire and Spinel.

Descriptive Note : Technical rept.,

Corporate Author : ARMY MATERIALS AND MECHANICS RESEARCH CENTER WATERTOWN MASS

Personal Author(s) : McCauley,James W.

Report Date : JAN 1972

Pagination or Media Count : 20

Abstract : Research on new materials demands sophisticated concurrent characterization not only to optimize fabrication parameters, but also to insure future quality control. The use of polarized light in a modified polariscope has been used to characterize transparent ingots of sapphire (Al2O3) and spinel (MgAl2O4). Since sapphire is birefringent, the spatial distribution of grain boundaries is easily monitored and can be related to the processing parameters; several examples of cracked and uncracked sapphire disks are presented. Further, the use of the polariscope is also valuable for the characterization of cubic materials like spinel. Grain boundaries cannot be observed as with sapphire, but the distribution of strain birefringence in the ingots provides useful processing modification data. (Author)

Descriptors :   (*SAPPHIRE, OPTICAL PROPERTIES), (*SPINEL, OPTICAL PROPERTIES), (*CRYSTALS, NONDESTRUCTIVE TESTING), POLARISCOPES, CRYSTAL GROWTH, SINGLE CRYSTALS, QUALITY CONTROL, BIREFRINGENCE

Subject Categories : Test Facilities, Equipment and Methods
      Crystallography
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE