Accession Number : ADA309969

Title :   Fracture Toughness and Crack Growth of Zerodur.

Descriptive Note : Technical memo.,

Corporate Author : NATIONAL AERONAUTICS AND SPACE ADMINISTRATION GREENBELT MD GODDARD SPACE FLIG HT CENTER

Personal Author(s) : Viens, MIchael J.

PDF Url : ADA309969

Report Date : APR 1990

Pagination or Media Count : 27

Abstract : The fracture toughness and crack growth parameters of Zerodur, a low expansion glass ceramic material, were determined. The fracture toughness was determined using indentation techniques and was found to be 0.9 MPa.m1/2. The crack growth parameters were determined using indented biaxial specimens subjected to static and dynamic loading in an aqueous environment. The crack growth parameters n and ln(B) were found to be 30.7 and -6.837, respectively. The crack growth parameters were also determined using indented biaxial specimens subjected to dynamic loading in an ambient 50% relative humidity environment. The crack growth parameters n and ln(B) at 50% relative humidity were found to be 59.3 and -17.51, respectively.

Descriptors :   *TOUGHNESS, *GLASS, *FRACTURE(MECHANICS), *CERAMIC MATERIALS, MICROSTRUCTURE, MODULUS OF ELASTICITY, THERMAL STABILITY, STRENGTH(MECHANICS), CRACK PROPAGATION, DEFECTS(MATERIALS), FATIGUE(MECHANICS), BIAXIAL STRESSES, HARDNESS, POISSON RATIO, LITHIUM ALLOYS.

Subject Categories : Ceramics, Refractories and Glass

Distribution Statement : APPROVED FOR PUBLIC RELEASE