| 摘要 |
PCT No. PCT/FI88/00192 Sec. 371 Date Jun. 5, 1990 Sec. 102(e) Date Jun. 5, 1990 PCT Filed Nov. 30, 1988 PCT Pub. No. WO89/05204 PCT Pub. Date Jun. 15, 1989.The invention concerns a method for the preparation of moulds and cores used in the casting of metals. In the method the moulds and cores are prepared out of a granular moulding material as well as out of a binder agent that binds the moulding-material granules together. The binder agent used for the moulding mix is an anorganic salt, sodium aluminate, soluble in water and having a high melting point, as a rule higher than the casting temperature, which said salt is mixed with the granular moulding material as binder-agent solution dissolved in water. In the moulding process the binder agent is crystallized out of its water solution by microwave energy so that the binder agent forms a solid bridge between the granules of moulding material, said bridge binding the granules of moulding material together. The combination formed by the binder agent and the moulding material is chosen so that the binder agent and the main minerals of the moulding material are chemically unreactive with each other at the moulding and casting temperatures. |
