FAILURE ANALISIS OF CRUCIBLE USED FOR RECYCLING OF MAGNESIUM ALLOYS
镁合金回收用坩埚失效原因分析

Crucible of holding furnace used in the magnesium recycling scrapped after commissioning for 3-4 months,due to thinning too much of the bottom part. The substance sticking to the bottom of crucible was analyzed with ICP-AES and observed with optical microscope, the magnesium melt composition at different depths was also analyzed using an emission spectrometer. The mechanism is that due to density difference,the substances generated in the recycling process drop onto the bottom of the crucible, resulting in a layer with high content of aluminum, manganese and iron on the bottom. Such a layer is active to react with the crucible material,generating a hard and brittle layer of inter-metallic compound. The scaling and spal- ling of the compound results in thinning of the crucible substrate,progrssively causing the failure.