title: Fracture Toughness of Advanced Ceramics at Room Temperature.
abstract: This report presents the results obtained by the five U.S. participating laboratories in the Versailles Advanced Materials and Standards (VAMAS) round-robin for fracture toughness of advanced ceramics. Three test methods were used: indentation fracture, indentation strength, and single-edge pre-cracked beam. Two materials were tested: a gas-pressure sintered silicon nitride and a zirconia toughened alumina. Consistent results were obtained with the latter two test methods. Interpretation of fracture toughness in the zirconia alumina composite was complicated by R-curve and environmentally-assisted crack growth phenomena.
authors.affiliation: National Institute of Standards and Technology, Gaithersburg, MD 20899.
authors.forename: George D
authors.initials: GD
authors.lastname: Quinn
authors.affiliation: National Aeronautics and Space Administration, Lewis Research Center, Cleveland, OH 44135.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Salem
authors.affiliation: Worcester Polytechnic Institute, Worcester, MA 01609.
authors.forename: Isa
authors.initials: I
authors.lastname: Bar-On
authors.affiliation: Worcester Polytechnic Institute, Worcester, MA 01609.
authors.forename: Kyu
authors.initials: K
authors.lastname: Cho
authors.affiliation: St. Gobain, Norton Industrial Ceramics Corp., Northboro, MA 01532.
authors.forename: Michael
authors.initials: M
authors.lastname: Foley
authors.affiliation: Allied-Signal, Garrett Auxiliary Power Division, Phoenix, AZ 85010.
authors.forename: Ho
authors.initials: H
authors.lastname: Fang
keywords: advanced ceramic; alumina; fracture; fracture toughness; indentation; round-robin; silicon nitride; zirconia