한국주조공학회

The effect of Al2Ca on the oxidation resistance and tensile property of Al-5Mg alloys was investigated. According to the TGA (Thermogravimetric analysis) result at 550oC after 24hrs, the Al-5Mg alloy showed parabolic behavior with weight gain. On the other han other hand, there was almost no difference in the weight changes of the Al2Ca added Al-5Mg allo 5Mg alloys during the oxidation. It was thought that the improvement of oxidation resistance in Al2Ca added Al-5Mg alloys might be due to the formation of a protective oxide layer with CaO and MgO on the surface. The microstructures of the alloys showed showed grain refinement with an increasing Al2Ca content. From the tensile test, the yield strength of the alloys were improved with an increasing Al2Ca content. The 0.07m 0.07mass% Al2Ca added Al-5Mg alloy showed similar elongation and increased strength,simultaneously. It was considered that the addition of Al2Ca, which was superior in the oxidation resistance of Al, reduced the formation of Mg oxides and inclusions during the alloying. This, partly led to the improvement of tensile properties.

Al-Mg alloy, Al2Ca, Oxidation resistance, Tensile property