Method and apparatus for near net shape casting (nnsc) of metals and alloys

An apparatus (1) for continuous Near Net Shape casting of a liquid metal (10) into a metal strip (34) having a strip width (31) and a strip thickness (29) on a chilled substrate (36) moving in a first direction (5), the apparatus (1) comprising:

• a head box (150) proximal to and above the chilled substrate (36),
• wherein the head box (150) is adjacent to and hydraulically connected to a launder (133) supplying the liquid metal (10),
• the head box (150) comprising:
• a compartment (160) receiving the liquid metal (10) from the launder (33), the compartment (160) comprising
• an upper portion (155) and a bottom portion (166) opposite the upper portion (155);
• an angled front wall (170) comprising a reverse flow wall (172) within the compartment wherein the angled front wall (170) is attached to the upper portion (155) through a pivoting device (180);
• two opposite side walls (152) proximal to and sealingly engaging the angled front wall (170);
• a weir (162) attached to the two opposite side walls and opposite the angled front wall (170);
• a bottom portion (166) attached or proximal to each of the angled front wall (170), the two opposite side walls (152) and the weir (162) wherein a combination of the bottom portion (166), the angled front wall (170), the two opposite side walls (152) and the weir (162) retaining the liquid metal (10);
• and
• a dam (164) in the bottom portion (166) positioned longitudinally between the two opposite side walls (152) and located between the weir (162) and the reverse flow wall (172),
• wherein the weir (162) defining an opening (163) adjacent to the bottom portion (166) allowing passage of the liquid metal (10) into the compartment (160);
• wherein the bottom portion (166) serving as a back-wall (190) proximal to the reverse flow wall (172) defining a slot nozzle (168) therebetween and above the chilled substrate (36), and
• wherein the slot nozzle defining a smooth elongated cavity with a slot width (167) and a slot length (165), the slot width (167) defined between the back-wall (190) and the reverse flow wall (172) and the slot length (165) defined between the two opposite side walls (152), the slot nozzle (168) transferring the liquid metal to the chilled substrate (36),
• wherein the back wall (190) and the chilled substrate (36) are separated by a meniscus gap (169) and
• wherein the front wall (170) is movable around the pivoting device (180) and capable of increasing or decreasing the slot width (167).

A method for continuous Near Net Shape Casting of a liquid metal (10) into a metal strip (34) having a strip width (31) and a strip thickness (29) on a chilled substrate (36) moving in a first direction (5), the method comprising:

• transferring the liquid metal (10) to a head box in a controlled manner,
• the head box comprising:
• a compartment receiving and calming the liquid metal, the compartment comprising
• an upper portion and a bottom portion (166) opposite the upper portion;
• a front wall movably attached in the upper portion, the front wall comprising a reverse flow wall within the compartment reversing the flow of the liquid metal at least partially in a second direction opposite the first direction (5),
• wherein the reverse flow wall adjacent to the bottom portion and defining a slot nozzle therebetween;
• wherein the slot nozzle defining a smooth elongated cavity with a slot width and a slot length, the slot width is adjustable and defined in the first direction and the slot length is defined in a plane perpendicular the first direction (5), and
• transferring the liquid metal (10) in a velocity adjusted manner through the slot nozzle at least partially in the second direction to the chilled substrate (36) above a meniscus gap defined between the bottom portion and the chilled substrate (36).