Patent EA-001195-B1 (EA)
Title: Method for the directional solidificaionof molten metal and apparatus for carrying out said method
Inventor: HUGO FRANZ
IPC: C30B11/00
Filed: 1998-07-14
Abstract: 1. Method for the directional solidification of a molten metal, nickel for example, poured into a mold, by moving the mold out of a heating chamber and immersing the mold into a molten metal bath serving as a molten coolant metal, aluminum for example, having a lower melting point than that of the molten metal in the mold, a floating thermal insulation layer consisting of a loose material being placed on the molten coolant metal as sealant between the heating chamber and the mold, and before the mold penetrates through the thermal insulation layer and dips into the molten coolant metal, the heating chamber or the molten coolant metal is driven so far that the heating chamber contacts the thermal insulation layer or dips into it, characterized in that the thermal insulation layer is vigorously stirred or whisked by a motor-driven rake , paddle or stirrer. 2. Apparatus for the directional solidification of a molten metal, nickel for example, poured into a mold (5), comprising a means for moving the mold (5) out of a heating chamber (6) and immersing the mold (5) into a molten metal bath (10) serving as a molten coolant metal having a lower melting point than that of the molten metal in the mold (5), a molten aluminum bath for example, a floating thermal insulation layer (13) consisting of a loose material being placed on the molten coolant metal (10) between the heating chamber (6) an d the mold (5), and before the mold penetrates the thermal insulation layer (13) and dips into the molten coolant metal (10), the heating chamber (6) of the molten coolant metal (10) is driven so far that the heating chamber (6) contacts the thermal insulation layer (13) or dips into it, characterized by a rake or stirrer (19) driven by a shaker or vibration generator (17) and dipping into the thermal insulation layer (13), the shaker or the vibration generator (17) being fixedly disposed on the upper margin (16) of the crucible for the molten coolant metal (10) and the rake or stirrer (19) being operatively connected to the reciprocating drive member (18) of the shaker or vibration generator (17). 3. Apparatus according to claim 2, characterized in that the rake or stirrer (19 ) is configured as a ring (19) surrounding the mold (5), which is moved back and forth by the shaker (17) in a horizontal plane or rotated back and forth about the vertically disposed longitudinal axis of the crucible (5). 4. Apparatus according to claim 2, characterized in that the rake or stirrer (19 ) is configured as a grid or grate. 5. Apparatus according to claim 3, characterized in that the height of the ringshaped rake or stirrer (19) corresponds approximately to the thickness of the thermal insulation layer (13). 6. Apparatus according to any one of claims 3 to 5, characterized in that the movement of the rake or stirrer (19) is formed by the combination of an up-and-down movement with a back-and-forth movement or to-and-fro movement. 7. Apparatus according to one or more of claims 3 to 6, characterized in that the upper margin of the rake or stirrer (19) is supported on guides (21) by pins or bolts (20) extending in a vertical plane, which are provided on the upper margin (16) of the crucible (8) containing the molten cooling metal (10).