激冷型界面气隙的研究

用方形水冷铜型和铸铁型测试铸件－铸型界面气隙形成的时间；研究铝液压头高度Ｈ和铸型形状及表面粗糙度对气隙形成的影响。形成气隙需要的时间和坯壳厚度随 Ｈ的增加而增加；在铸铁型中，当 Ｈ＞２００ｍｍ时，二者随 Ｈ变化不大。在方形水冷铜型中，由于气隙的作用，坯壳表面角部和中部的温差由负到正，最后又变为负值；角部附近和中部的壳厚比也从大到小，然后又变大。铸型内表面的粗糙度影响形成气隙的时间，但不影响形成气隙时的壳厚。

On Gap Formation at Interface of Chilling Mould

A device has been built to detect the time of the formation of the gap between casting and mould. With this device, the effect of pressure head of melt and roughness of mould surface on the gap formation is investigated in water chilling mould and casting iron one. The results show that the time of the gap formation increases with the increase of pressure head. In the case of square mould with water chilling, the temperature difference between corner and middle on the surface of casting experiences a change of negative value through positive to negative. The solidified shell thickness in the corner, compared with that in the middle, changes from larger through smaller to larger.It is shown that the change of temperature and thickness of shell is due to the formation of the gap. It has been found that the roughness of the mould surface affects the time of the gap formation,but not the shell thickness solidified at the time of the gap formation.