ANALYSIS OF OVERFLOW CRITICAL VALUE FOR TiAl BASED ALLOY MELT DURING PROCESS OF CENTRIFUGAL CASTING
(Institute of Materials Science and Engineering, Harbin Institute of Technology,Harbin 150001, P. R. China)
Abstract: The method combining theoretical analysis with experimental verification was adopted, and the pressure distribution of TiAl based alloy melt poured in permanent mould during the process of centrifugal casting was analyzed. The expression of extra pressure itemΔpand the relations between the maximum angular velocityω0maxand melt heightH, pouring basin diameterD0were concluded. It provided theoretical guide for actual casting process. The analytical results showed that the pressure item affecting castings consists of static pressure and extra pressure during the process of centrifugal casting. The static pressure was determined by melt height, while the extra pressure was controlled by metal liquid density and rotating angular velocity. The pouring basin height and diameter should follow certain functional relation. Also, it showed that the value of maximum angular velocity decreased with increasing metal liquid height and pouring basin diameter.
Key words: angular velocity TiAl base alloy pressure distribution centrifugal casting