The nature of phase binding in the Al2O3-W cermet

The formation mechanism of bonds between the phases in the cermet Al2O3-W was studied by microstructure, local x-ray structure and mass spectrometric analyses. It is established that W and Al2O3 interact chemically at temperatures above 1800 deg C with the evolution of gaseous O2, WO3 and Al2O3. The interaction is intensified in the presence of liquid Al2O3. The phases feature a strong mutual adhesion due, probably, to a directional chemical bond between the atoms of W and the non-saturated bonds on the surface of Al2O3 of a structure imperfect as regards oxygen