| Abstrakt: |
Proceeding from the results of the performed package of research work, it was established that the chemical composition of metal in the surface-melted layer of high-temperature titanium alloy VT9 corresponds to standard requirements; and a lowering of aluminium content, an alloying element with vapour pressure higher, and an increase in the content of molybdenum and zirconium, alloying elements with vapour pressure lower than that of titanium, is observed. Investigations of the surface-melted layer showed that the penetration depth of the surface layer in ingots of high-temperature titanium alloy VT9 of 600 mm diameter reaches 8 mm, the ingot surface is high-quality mirror-like with characteristic vacuum etching, even microrelief without cracks, tears or lacks-of-fusion, its roughness is within the range of 3-4 class at a waviness of 0.2-0.6 mm. The surface-melted layer of the ingot has a finer structure, compared to base metal, and it consists of areas with isolated a-plates of 1.0-2.5 µm thickness, where the a-plates are gathered into colonies of 10-50 µm width, and the gaps between them are taken up by dispersed particles of 1-2 μm size, which can be the products of metastable phase decomposition. [ABSTRACT FROM AUTHOR] |
