Recycle Process for Off-Grade Ti Scrap by Using Electrochemical Deoxidation and Electron Beam Melting

The expansion of the titanium industry and the rising demand for titanium have underscored the increasing significance of technologies focusing on deoxidation, purification, and recycling of off-grade titanium scrap. The substandard titanium scrap is utilized in the production of ferro-titanium for the steel manufacturing process. The deoxidation process through electrolysis has been acknowledged as a feasible method for removing oxygen by employing a reducing agent. This theoretically enables the reduction of oxygen levels from off-grade to on-grade levels. Moreover, Electron Beam Melting (EBM) technology is employed in the production of 4N5 grade titanium utilized in semiconductor applications. This process is recognized as a refining technique involving the evaporation of organic and inorganic impurities under ultra-high energy conditions, typically in the range of several mega-watt per unit area, within an ultra-high vacuum environment. The utilization of on-grade titanium, produced via the electrolysis process, is anticipated as a viable target material for physical vapor deposition (PVD) in semiconductor applications following the EBM procedure. In this study, electrolysis was performed utilizing molten salt composed of MgCl₂. The selection of the most suitable electrode material was determined by assessing the effectiveness of the electrolyte and measuring the cell potential using Cyclic Voltammetry (CV). Additionally, the deoxidation process was confirmed by conducting Chronoamperometry (CA) measurements. Subsequently, any residual impurities were removed through post-processing. Titanium ingots were manufactured from high-quality titanium obtained through electrolysis and refined utilizing an EBM method. Real-time monitoring of oxygen partial pressure was conducted through Residual Gas Analysis (RGA) measurements to track fluctuations in oxygen concentration during the process. The oxygen concentration in the titanium samples was assessed in off-grade, on-grade, and ingot samples utilizing a Nitrogen/Oxygen content analysis. Additionally, the existence of impurities in the ingot was confirmed through the implementation of Inductively Coupled Plasma (ICP-OES) analysis.