| 摘要 |
<p>PURPOSE:To purify molten Al or a molten Al alloy by filtering it with >=2 kinds of fire resistant filters having different pore sizes to thoroughly remove inclusions in the molten metal. CONSTITUTION:Molten Al or a molten Al alloy contains inclusions such as refractory fragments mixed in the melting stage, Al oxide and Al nitride. The inclusions are divided roughly into beltlike inclusions (a) having about 1mum width and >=1,000mum length and fine particles (b) having about 1-10mum diameter. The molten metal contg. inclusions is first passed through a ceramic filter or a plurality of ceramic filters >=1 time to remove the inclusions (a) by filtration. After adding a grain refiner such as Ti or a Ti-B compound, the molten metal is further passed through a ceramic filter having a smaller pore size >=1 time to remove the fine particles (b). Thus, the molten Al or the molten Al alloy is purified without clogging the filters and reducing the yield of the grain refiner such as Ti.</p> |
