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Some Physical Properties of High‐Density Thorium Dioxide
Author(s) -
LANG S. M.,
KNUDSEN F. P.
Publication year - 1956
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1956.tb15615.x
Subject(s) - shear modulus , bulk modulus , materials science , modulus , aggregate modulus , composite material , young's modulus , dynamic modulus , poisson's ratio , brittleness , thermal expansion , tangent modulus , thermodynamics , dynamic mechanical analysis , poisson distribution , mathematics , statistics , physics , polymer
The values for a number of physical properties are reported for a very high density form of thorium dioxide. When specimens of a mixture of 99½% ThO 2 and ½% CaO, by weight, were hydrostatically pressed at 30,000 lb. per sq. in. and heat‐treated for 1 hour at 1800°C., they attained 99.0% of theoretical density. All the test specimens were extremely brittle. Physical‐property values determined at room tempera‐ ture were the following: lattice constant; bulk and theoretical (X‐ray) densities; compressive and impact strengths; Knoop hardness; modulus of rupture and Young's modulus, determined by a static method; Young's modulus and the shear modulus, determined by a dynamic method; Poisson's ratio and the bulk modulus, calculated from the dynamic‐test data; and the velocity of sound through the material. The properties determined at elevated temperatures were the following : linear thermal expansion modulus of rupture and Young's modulus, determined by a static method; Young's modulus and the shear modulus, determined by a dynamic method; and Poisson's ratio, calculated from the elevated‐temperature dynamic‐test data. “Martin's diameter” grain counts were taken for the material both before and after heat‐treatment.