METHOD FOR CASTING THE AL-SI ALLOY FOR HARD OXIDATION ANODIZING

摘要

PURPOSE: A casting method of Al-Si alloy for hard anodizing is provided to inhibit the anodizing reaction velocity of aluminum casting alloy in Al-Si system and to minimize the generation of Si precipitates on an aluminum alloy casting product which produces defects in an anodizing film. CONSTITUTION: A casting method of Al-Si alloy for hard anodizing executes the following steps. One lower mold (10) with the first molten metal inlet and one upper mold(20) for the second molten metal inlet are provided. A porous primary crystal collector(30) is arranged in a cavity which is formed when the lower mold and the upper mold is combined together. Semisolid molten aluminum is poured and the molten metal fills the cavity. Certain strength of pressure is applied onto a space(40) through a pressurizing line to make the molten metal with silicon component content pass through the opening of the porous primary crystal collector in a state that closed the first molten metal and the second molten metal inlet. Globular aluminum primary crystal particle layer is formed on the surface of the primary crystal collector and molten metal is condensed in the remainder including the porous primary crystal collector to produce foundry products. [Reference numerals] (AA) Prepare upper, lower molds; (BB) Form a cavity and arrange a collector; (CC,EE) Molten metal; (DD) Inject molten metal into a reaction chamber; (FF) Aluminum primary crystal particle layer(low Si content concentration); (GG) Aluminum liquid particle layer(high Si content concentration); (HH) Harden the molten metal; (II) Compression; (JJ) Compress the molten metal using a space unit