Interfacial adsorption of solute atoms is a promising means to tune heterogeneous nucleation. In this study, a new method has been established to theoretically evaluate the effect of solute addition on the nucleation potency of heterogeneous nucleation interfaces. The evaluation consists of three steps: (1) analyzing the solute adsorption behavior; (2) determining the nucleation mode; and (3) evaluating the effect of solute adsorption on nucleation potency using the solute-adsorbed interface model. A combination of the ab initio and molecular dynamics methods together with the two-phase thermodynamic model was used to evaluate a prototype Al–Cu/(0001) sapphire interface. It is found that solute Cu atoms adsorb at the interface between the melt and (0001) sapphire interface. The adsorption is driven by the strengthening of the Cu–Al bonds as revealed by the Bader charge analysis which is demonstrated to reduce interfacial energy. Furthermore, it is revealed that the interfacial adoption of Cu results in the formation of an Al–Cu adsorption layer, which enhances the interfacial chemical affinity thus enlarging the nucleation driving force. Meanwhile, the lattice mismatch between the sapphire substrate and the primary Al (α-Al) nucleus is decreased by Cu addition, which lowers the barrier for nucleation. The above two effects together increase the nucleation potency of the studied interface, which is in good agreement with previous experiments. It is proposed that the effect of solute adsorption shall be considered in the search for effective substrates for tuning the nucleation.

Chamfer technology, with funnel-shaped curved surface on the narrow side of the mold, is a novel technology that can effectively improve the quality of continuously cast products. This study reviews the available literature on the theoretical and applied research in chamfer technology to provide an in depth analysis of the employed approaches and the obtained results. According to theoretical research results, combined with the working conditions of slab caster, patented technologies and related equipment were developed. The research has broken the technology bottlenecks of the industrial application, while ensuring a long-life operation of the chamfer mold. In recent years, chamfer technology, which is used in slab casting processes, can prevent transverse corner cracks to form at the slab surface of micro-alloyed steel completely. Chamfer technology, which is used in thin slab casting processes, can reduce the occurrence of longitudinal surface crack of the slabs and straight edge seam defects of the rolled strip. In addition, chamfer technology, which is used in a continuous casting bloom, can reduce the risk of internal cracks and avoid the off-corner cracks occurring in as-cast bloom.

Dendritic morphology was investigated in a directionally solidified magnesium-zinc alloy using synchrotron X-ray tomography and electron backscattered diffraction. Unexpectedly, primary dendrites grew along $$ {\langle}21\overline{3}1 {\rangle}$$ ⟨ 21 3 ¯ 1 ⟩ , rather than the previously reported $${\langle} 11\overline{2} 0{\rangle} $$ ⟨ 11 2 ¯ 0 ⟩ and $${\langle} 22\overline{4}5 {\rangle}$$ ⟨ 22 4 ¯ 5 ⟩ directions. Further, seven asymmetric sets of side branches formed, instead of six-fold symmetric arms, evolving with three coexisting morphologies per trunk of: traditional, seaweed structure, and free growth. The anomalous growth is attributed to the imposed thermal gradient and zinc-induced interfacial energy anisotropy variations.