@article{oai:mdu.repo.nii.ac.jp:00000746, author = {OHNO, TAKAFUMI and KUROIWA, AKIHIRO and IGARASHI, YOSHIMASA and YONEDA, TAKANORI and INOUE, YOSHIHISA and SEKIGUCHI, YUUJI and MIGO, SHINYA}, issue = {1}, journal = {松本歯学}, month = {Apr}, note = {application/pdf, The purpose of this study was to evaluate the influence of casting molds with low permeability on the castability of pure titanium with an all directional pressured type casting machine. Two types of phosphate bonded casting molds were used, T-INVEST and T-INVEST C&B. We reported high performance of castability of pure titanium with an all directional pressured type casting machine, if the permeability of the investment was lower as possible. Specially prepared metal sealed rings to decrease gas permeability of casting mold were used. Two sizes of sprue condition were prepared, 1.26 and 1.48mm, under a casting pressure of 8kgf/cm^2. Five sizes of casting molds were prepared with mold diameters of 25, 35,45,55 and 65mm. The following results were obtained: A high percentage of castability was gained in T-INVEST using a high gas permeability casting mold with the sealed ring. A low percentage of castability was gained in T-INVEST C&B using a low gas permeability casting mold with the sealed ring. Back pressure action in the casting mold of T-INVEST C&B seemed to produce negative effects regarding the castability. These results indicated that the sealed ring was effective to promote pure titanium castability with a mold of high permeability.}, pages = {101--108}, title = {Studies on the Castability of Pure Titanium (Part 4) Castability in case of casting molds with low gas permeability}, volume = {24}, year = {1998} }