A Comparison of the Family of AlTiB Refiners and their Ability to Achieve a Fully Equiaxed Grain Structure in DC Casting

There are a number of grain refiners based on the AlTiB system used in DC casting. These vary in both concentration and Ti:B ratio. An in depth experimental programme has been performed to compare the effectiveness of some of these refiners in DC casting. One of the key success criteria used was to compare the amount of TiB(2) from the different refiners required to achieve a fully equiaxed grain structure. The key role of TiB(2) particles is highlighted. The results are discussed in relation to recent theories and modelling on the key characteristics of the TiB(2) particles. In particular, the particle size distributions of the different refiners are used to interpret the effectiveness of the refiners.