Bogomol Y. The forming of structure and properties of the directed-crystallized alloys of systems В4С - МеIVВ2

The phase diagrams of the quasi-binary systems В4С - ТіВ2, В4С - ZrВ2, В4С - HfВ2, are explored and specify of its eutectic parameters. The three-phases directly reinforced composites LaB6-В4С-ZrВ2 are developed and shown that they consist of boron carbide matrix reinforced by zirconium diboride with including of emission-active phase of lanthanum hexaboride. Influence of additions of amorphous boron on the process of sintering of the eutectic alloys В4С - МеIVВ2 is shown. By metallographic analysis it is shown, that the directed crystallized eutectic alloys В4С-ТіB2, В4С-ZrB2 and В4С-HfB2 consist of boron carbide matrix reinforced by fiber and plate inclusions of transitional metals diborides. The influence of kinetic parameters of growth on microstructure and physico-mechanical characteristics of directed crystallized eutectic alloys are explored. Keywords: boron carbide, transitional metals diborides, powders, eutectic, directed reinforced composites, ceramic cathode assemblies.