Thixo-Giessverfahren und Thixo-Giesslegierungsmaterial
摘要
In carrying out a thixocasting process, a material in a semi-molten state is produced under a heating from an aluminum alloy material which has a thermal characteristic that a first angle endothermic section generated by the melting of an eutectic crystal and a second angle endothermic section generated by the melting of a component having a melting point higher than an eutectic point exist in a differential calorimetric curve. The casting involves a primary pressing stage and a secondary pressing stage. A start point of a primary pressing stage is established at a point when the temperature T of the material is in a range of T1 < T </= T4 in the relationship between the temperature T1 of a rise-start point in the first angle endothermic section and the temperature T4 of a peak of the second angle endothermic section. At the primary pressing stage, the charging of the material into a cavity in a casting mold is completed. A start point of a secondary pressing stage is established at a point when the temperature T of the material is in a range of T1 < T </= T4 in the relationship between the temperature T1 of the rise-start point in the first angle endothermic section and the temperature T4 of a drop-end point in the first angle endothermic section. At the secondary pressing stage, which is at a pressure larger than that of the primary stage the material is solidified. Specific Al-Cu-Si based alloy materials are disclosed. <IMAGE>
