The Effects of Various Types of Fluid Motion on the Structure of Ingots

摘要

A number of questions regarding the structure of ingots and the effects of fluid motion on this structure have long remained a puzzle to those involved in this area of solidification. In particular, the origin of the equiaxed grains has not yet been established. Likewise, no determination has been made of the mechanism by which structures are refined through mechanical or electromagnetic stirring of the liquid during freezing. Recent experimental results have shed new light on both of these areas, particularly with respect to the effect of fluid motion on grain size effects and also the presence of natural convection in ingots. A comprehensive picture of ingot solidification has resulted, along with a much more detailed knowledge of the effects of fluid motion on structure. The experiments, results and conclusions reached in these investigations are described in this survey. (Author)