Use of CO_2-Snow for Protecting Molten Magnesium from Oxidation

摘要

When processing magnesium alloys, prevention of oxidation of the liquid metal is of prime importance, because of the high oxygen affinity of molten magnesium. A special danger of environmental pollution occurs from the usage of protective gases for molten magnesium. The protective gas SF_6, which is widely used nowadays, increases the greenhouse effect due to it's GWP of approximately 23900 relative to CO_2. At the Kyoto summit in 1997, this gas was detected as one of six gases to be restricted in use. The environmentally friendly alternatives are being examined by authors of this paper. The research goals of this group are to develop and to evaluate new methods for protecting the surface of magnesium melts. One possible alternative is covering the magnesium melt with CO_2-snow. The current results will be presented in the following paper.