The Vickers indentation technique used to evaluate thermal shock resistance of brittle materials
- Lab. d`Etudes et de Recherches sur les Materiaux-CNRS, Caen (France)
The establishment of transient thermal stresses during quenching brittle materials involves a number of parameters, such as Young`s modulus E, Poisson`s ratio v, coefficient of thermal expansion {alpha}, thermal conductivity of the material k, the size and shape of the sample, the quenching temperature difference {Delta}T, and the coefficient of heat transfer in the quenching medium h. The damage resulting from a critical thermal shock is governed by the toughness, the statistical distribution of initial surface flaws and thus by the rupture stress. It is shown here that, additionally to the preliminary determination of the material`s toughness and the quantification of the maximum value of the thermal transient stress, the combination of toughness and these thermal stresses yields descriptions of a new thermal shock resistance parameter for temperature differences {Delta}T lower than the critical one {Delta}{Tc}. The derivations will be verified on various microstructures of high-temperature superconducting ceramics, YBaCuO, and on alumina.
- OSTI ID:
- 529517
- Journal Information:
- Scripta Materialia, Vol. 37, Issue 4; Other Information: PBD: 15 Aug 1997
- Country of Publication:
- United States
- Language:
- English
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