Abstract
This study evaluated the effect of mold gas permeability and casting pressure on titanium castability using an all-directional pressure-type casting machine and two different kinds of phosphate-bonded investments with different levels of gas permeability. The castability values increased with increases in the mold diameter of the higher gas permeability investment (T-invest). The influence of casting pressure on castability showed different trends, depending on mold diameter. When large mold diameters were used, casting pressure was less critical for castability. Castability was not affected by mold diameter when lower gas permeability investment (T-invest C&B), or T-invest with a sealed ring were employed. Excellent, stable castability was achieved by casting pressure over 4 kgf/cm^2.These results indicate that the influence of casting pressure on castability showed different trends, depending on the level of gas permeability in the casting mold used.
