Abstract: A new plaster casting process for magnesium alloy is developed recently. Compared with ordinary plaster mold, the plaster mold for Mg alloy is characterized by its burning-proof. The paper describes the main properties of the molding material such as strength, shrinkage rate, resistance to cracking and reproducibility. And the tests to determine the above properties are also introduced. It is found that Mg alloy castings of small or middle size produced by this plaster mold process can get perfect surface and high dimension preciseness. It is concluded that this new process is practical and valuable to be further developed.

Key words: magnesium alloy, investment casting, plaster mold