The high-quality precision casting of titanium alloys

A technique for the high-quality precision casting of titanium alloys has been developed that consists of the instantaneous dissociation of oxide at the metal-mold interface, followed by the rapid absorption and diffusion of the dissociated oxygen into the subsurface of the cast parts during solidification and cooling. In centrifugal casting trials using less molten alloy than required to completely fill the mold, the results suggest that the melt flowing in the mold cavities maintains contact with the vertical inside walls and directionally solidifies from the far end of the cavity to the gate, corresponding to the gradient in the centrifugal force on the horizontal plane. This force enhances the removal of defects, such as entrapped gas bubbles and solidification shrinkage. The results have enabled the development of a two-dimensional model to simulate melt flow during centrifugal casting. Author’s Note: Unless otherwise indicated, compositions are given in weight percent. Ken-ichiro Suzuki earned his Ph.D. at Tohoku University, Faculty of Engineering. He is currently a visiting professor at the Graduate School of Iron and Steel Technology at Pohang University of Science and Technology.