A novel electromagnetic cold crucible-based continuous melting- solidification process for high-purity and highly densified Ti alloy ingots

Titanium alloys are widely used in high-end fields such as aerospace and biomedical engineering due to their outstanding specific strength and excellent corrosion resistance. However, existing titanium alloy ingot preparation technologies generally suffer from high energy consumption, poor microstructural uniformity, and a high density of internal defects. To address these challenges, this study integrates electromagnetic cold crucible melting with continuous casting and proposes a novel continuous melting-solidification technique for titanium alloys. Using this approach, two of the most widely applied titanium alloys, CP-Ti and Ti-6Al-4 V, were successfully fabricated and systematically compared with conventionally cast titanium alloy ingots. The results show that, in continuously melted-solidified titanium alloy ingots, impurity elements are preferentially segregated toward the top of the ingot, resulting in substantially lower impurity levels in the effective steady-state portion of the ingot. Notably, after removal of the impurity-enriched terminal top region, the effective portion of the continuously processed Ti-6Al-4 V ingot satisfies the corresponding Extra-Low Interstitial (ELI) compositional requirements. Compared with conventional static casting, the micro-shrinkage porosity within the continuously solidified ingots is reduced by one order of magnitude, while macroscopic casting defects are reduced by approximately two orders of magnitude. This indicates that the proposed technique is capable of enhancing ingot purity and densification while simultaneously improving production efficiency, thereby providing a more efficient and cost-effective manufacturing route for titanium alloy metallurgy.