Accession Number : ADA317087

Title :   Laser-Induced Controlled Flaw Testing in Ceramics.

Descriptive Note : Final rept. 1 Apr 91-31 Aug 96,

Corporate Author : LEHIGH UNIV BETHLEHEM PA DEPT OF MATERIALS SCIENCE AND ENGINEERING

Personal Author(s) : Chou, Y. T. ; Harmer, M. P. ; Huennekens, J. P.

PDF Url : ADA317087

Report Date : 30 SEP 1996

Pagination or Media Count : 8

Abstract : The present investigation yields significant results in controlling crack formation in transparent ceramic crystals (LiF, MgO, ZrO2, and Al2O3), as well as in amorphous solids (fused quartz and PMMA) through a series of systematic experimentations and theoretical modeling of the laser-solid interaction. The impact of such success is the extension of another dimension in the investigation of many mechanical and physical problems from the current two-dimensional simplifications to three-dimensional phenomena. The critical control of the formation of internal cracks allowed us, for the first time to examine the interaction of three-dimensional cracks in PMMA and fused quartz, and to validate the general predictions of the available theoretical analyses. We also studied the interaction of a penny-shaped internal crack and dislocations in lithium fluoride single crystals, a phenomenon currently under renewed extensive investigation for fundamental understanding of the ductile vs. brittle behavior of solids.

Descriptors :   *CERAMIC MATERIALS, *LASER APPLICATIONS, *LITHIUM FLUORIDES, TEST AND EVALUATION, CONTROL, MODELS, INTERACTIONS, PHYSICAL PROPERTIES, CRACKS, POLYMETHYL METHACRYLATE, TRANSPARENCE, SINGLE CRYSTALS, AMORPHOUS MATERIALS, SOLIDS, MECHANICS, THREE DIMENSIONAL, DEFECTS(MATERIALS), BRITTLENESS, DISLOCATIONS, ALUMINUM OXIDES, INTERNAL, ZIRCONIUM OXIDES, MAGNESIUM OXIDES.

Subject Categories : Ceramics, Refractories and Glass
      Inorganic Chemistry
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE