An approach for selecting alloying elements to control the size of an in situ formed phase is proposed based on a G–D map, which is derived from basic thermodynamic and kinetic principles. The G–D map is divided into four zones. Elements in Zone III are potential refiners whereas those in Zone II should be avoided in processing. When applied to the Mg₂Si/Mg system, we find that Sr, P, Sb and Sn refine Mg₂Si by increasing the nucleation rate and inhibiting the growth rate. Conversely, Ti, Mn, Zr and V contribute to coarse-shaped Mg₂Si by postponing nucleation. The content of alloying elements should be matched with the Si content, and the required amount can be pre-estimated from the G–D map. Mg₂Si formed in Mg-Al and Mg-Zn alloy is smaller than that in Mg-Si and Mg-Mn alloy, because Al and Zn suppress the diffusion of Si, particularly at high Si contents. The predictions of this approach are consistent with experimental observations. Hence, the G–D map can provide useful guidance for quantitative phase refinement design.

基于G-D图，提出了一种选择合金元素来控制原位形成相尺寸的方法，该图是从基本的热力学和动力学原理得出的。的G-d地图被分成四个区。III区中的元素是潜在的提炼者，而II区中的元素应避免在加工中使用。当应用于Mg ₂ Si / Mg系统时，我们发现Sr，P，Sb和Sn通过增加成核速率和抑制生长速率来细化Mg ₂ Si。相反，Ti，Mn，Zr和V有助于形成粗大的Mg ₂Si通过推迟成核。合金元素的含量应与Si含量匹配，所需量可以从G–D图中预先估算。在Mg-Al和Mg-Zn合金中形成的Mg ₂ Si小于在Mg-Si和Mg-Mn合金中形成的Mg ₂ Si，这是因为Al和Zn抑制了Si的扩散，特别是在高Si含量下。这种方法的预测与实验观察一致。因此，G–D图可以为定量相优化设计提供有用的指导。