Influence of diluent gas on the oxidation behavior of molten magnesium in atmospheres containing HFC-134a

A comparative study of oxidation behavior of molten magnesium in HFC-134a/air and HFC-134a/CO₂ atmospheres was made. It was found that the oxidation behavior of molten magnesium in HFC-134a/air mixtures was different from that of molten magnesium in HFC-134a/CO₂ mixtures, and the difference was increased with decreasing the concentration of HFC-134a. As the concentration of HFC-134a was high, the oxidation rate of molten magnesium in HFC-134a/CO₂ atmospheres was slightly slower than that in HFC-134a/air atmospheres. However, when the concentration of HFC-134a was low, the oxidation rate of molten magnesium in HFC-134a/CO₂ atmospheres was much slower than that in HFC-134a/air atmospheres. These results indicate that the atmosphere of HFC-134a with CO₂ as diluent can provide more effective protection to molten than that with air diluent at the same HFC-134a concentration, especially when HFC-134a concentration is low.