Ivchenko Z. Theoretical and technological fundamentals of formation of centrifugal castings of the ВТ5Л titanium alloy in graphite shell moulds

The thesis is dedicated to investigation of laws of formation of castings of the titanium alloy manufactured by the centrifugal casting with vertical axis of rotation in the graphite shell moulds in order to prevent occurrence of surface flaws on these castings. The paper describes investigation of changes in the linear dimensions and ability of the graphite shell mould to create gas in case of its preliminary calcinations in the gaseous atmosphere with reducing properties, determination of value of its resistance to rupture during static bending depending on several parameters of the used resin and graphite suspension, fraction of the granular pitch coke, drying temperature of coating layers. Mechanism of occurrence of the surface flaws of the graphite shell mould is described. Production process for manufacture of consumable electrodes made of the melted titanium alloy and pouring unit is developed. Level of mechanical properties of the alloy in the electrodes and castings is determined. Analytical expressions are developed for calculation of the level of mechanical properties of the titanium alloy and content of the oxygen and nitrogen in the alloy as the factors controlling the level of mechanical properties of the alloy. ted.