Production of High-Purity Titanium by Electron Beam Melting and Refining Process

In this study, the research aimed to produce high-purity titanium ingots using the electron beam melting technique. The semiconductor materials are required to possess a purity level of 4N5, signifying that the presence of inorganic impurities must not surpass 50 parts per million (ppm). The quantity of inorganic impurities that evaporate in titanium significantly varies based on the reactivity and vapor pressure of the inorganic impurities at elevated temperatures and pressures. The electron beam, characterized as a Gaussian beam, is currently attracting considerable interest in the industry because of its high-purity refining capabilities employed in the manufacturing of rare metals. During the refinement process employing this technology, the levels of inorganic metal impurities, particularly iron and aluminum, present in the ingot, vary depending on factors such as beam radius, and beam power density. In the case of refractory metals with high melting points, such as tungsten or tantalum, the vapor pressure is relatively lower compared to that of titanium, which is the substrate material. Therefore, the removal procedure requires acknowledging the loss of titanium. This is closely linked to the rate of product manufacturing. Therefore, it is essential to conduct research focused on predicting the thermodynamic evaporation quantity of each element. It is essential to minimize the loss of titanium and determine the threshold for removing elements with low vapor pressure. In this study, an initial evaluation was performed to assess the electron beam output and temperature fluctuations in titanium, aiming to facilitate precise impurity control. Subsequently, the equilibrium impurity composition was thermodynamically predicted using the specified temperature and chamber pressure conditions. The concentration of impurities in the titanium ingot produced using the electron beam melting technique was determined through ICP-OES analysis. This data was then compared with the composition anticipated by thermodynamic calculations.