DEVELOPMENT PROGRAMS IN INVESTMENT CASTING

A number of development programs were discussed during the WTEC team's visits although few details were given.

Titanium Casting

A program at Tohoku University is investigating titanium alloy casting using a calcia crucible. To prevent the crucible from decomposing during melting, pressure in the melting chamber is raised; and when the metal is poured, the pressure is lowered to avoid contaminating the metal.

Directional Solidification and Single Crystal Casting

A program at Tokyo University is investigating methods of making these products.

Nonconventional Pattern Materials

Kubota uses naphthalene as a pattern material for a lost pattern process that makes larger castings. Naphthalene is easily formed by injection molding and should burn out cleanly without forming toxic residues. However, naphthalene itself is classified as a hazardous air pollutant by the EPA and would not be permitted in U.S. foundries unless methods of removing it from the atmosphere were also implemented. There is another problem: odor --naphthalene is commonly sold in the United States as moth balls.


Published: March 1997; WTEC Hyper-Librarian