Peculiarities of crystallization of alumina, yttria and rare-earth element oxides of yttria subgroup in an optical furnace

Anomalous increase in specific volume upon crystallization of some alloys in the zirconia–yttria–erbia system

“…The porosity was measured by using the method of hydrostatic weighing with preliminary samples vacuum treatment. 22 The weighing accuracy was up to 0.0001 g and the weighing error did not exceed 0.5-1%.…”

“…In this paper, we propose to esti- mate changing of true specific volume (( V/V ) true ) with the use of the melt pool and ingot side views at axial symmetry approximation. 22 According to (1)…”

“…The obtained results showed that there was no open porosity in the fused samples. The closed porosity was 22 :…”

“…Such substances are the heavy lanthanides Ho 2 O 3 , Tm 2 O 3 , and Yb 2 O 3 oxides. 22 It is possible that the alloys of the above mentioned oxides with each other and with Er 2 O 3 and Y 2 O 3 can have the similar properties. The addition of ZrO 2 or HfO 2 into such substances in the concentration area of the H phase primary crystallization leads to an additional volume increase due to the appearance of chemically induced vacancies in the metal sublattice.…”