THERMAL MEASUREMENTS: STANDARD MEASURES OF THERMAL EXPANSION MADE OF MONOCRYSTALLINE ALUMINUM OXIDE FOR A BROAD RANGE OF TEMPERATURES

摘要

Standard measures of linear thermal expansion made of moncrystalline aluminum oxide have been developed. The measures have a 59 deg orientation relative to the trigonal axis of the crystalline lattice. The raw material for making the measures in obtained by the Stepanov's method of growing shaped monocrystalline semifinished products with a highly accurate crystallographic orientation from a melt. The parameters of the measures are optimized for testing high-temperature relative dilatometers with transducers made of polycrystalline corundum. The coefficient of linear expansion of the new measures was checked in the range 90-1800 K and exact values of the coefficient were obtained for a broad range of temperatures.