TiAlNb合金离心铸造过程中溢出临界值分析

Analysis of the Overflow Critical Value for TiAlNb Alloy During the Centrifugal Casting Process

分析了金属型离心浇注TiAlNb2 9合金过程中浇道内压力分布情形 ,得出了离心浇注过程中产生的附加压力项ΔP的表达式以及最大转动角速度与金属液高度和浇道直径之间的关系。试验结果表明 ,离心浇注过程中 ,作用在熔体上的压力由静态压力和附加压力两部分组成 ,静态压力由金属液高度决定 ,附加压力主要由金属液密度以及旋转角速度来决定。浇道高度和直径之间应满足一定的函数关系 ,金属液高度为浇道高度的一半时较为理想。最大允许旋转角速度值随金属液高度和浇道直径的增大而减小。

Pressure distribution in pouring basin for Ti 3Al - Nb alloy during the centrifugal casting process in permanent mould is analyzed. The expression of extra pressure item ΔP during the centrifugal casting process as well as relationship between the maximum angular velocity and melt height, pouring basin diameter is concluded. The results showed that pressure acting on melt consists of static pressure and extra pressure during the centrifugal casting process. Static pressure is determined by melt height while extra pressure is determined substantially by density of molten metal and rotating angular velocity. Pouring basin height and diameter should follow a certain functional relation. It is the better choice that height of liquid metal is a half of pouring basin height. The value of allouable maximum angular velocity increased with an increase of melt height and pouring basin diameter.