METHOD FOR FORMING FINER CRYSTAL GRAINS OF AL OR AL ALLOY

摘要

PURPOSE:To form efficiently the finer crystal grains of an Al or Al alloy casting by filtering the melt of the Al or Al alloy to remove inclusions, etc. therefrom then adding continuously an agent for forming the finer crystal grains to the filtered melt while filtering said agent. CONSTITUTION:The melt of the Al or Al alloy is filtered to remove Al2O3 and other impurity inclusions therefrom and thereafter the agent for forming the finer crystal grains which is made into a rod shape and contains comps. such as Al-Ti-B is added thereto by using sintered aggregate consisting of 15-30 mesh refractories as the filter for the agent for forming the finer crystal grains. The finer crystal grains of the casting of the Al and Al alloy are stably and effectively formed by adding the agent for forming the finer crystal grains while the coarse oxide and TiB2 contained therein are filtered.