Casting of molten metal in an open ended mold cavity

Abstract

When a body of startup material has been interposed in the cavity between the starter block and a first cross sectional plane of the cavity transverse the axis thereof, the starter block has commenced reciprocating along the axis, and the body of startup material has commenced reciprocating in tandem with it, through a series of second cross sectional planes, layers of molten metal are successively superimposed on the body of startup material adjacent the first cross sectional plane of the cavity, and the layers promptly distend relatively peripherally outwardly from the axis under the inherent splaying forces therein. The invention confines the relatively peripheral outward distention of the layers with a casting surface which is peripherally outwardly flared about the axis of the cavity. Initially, at the circumferential outline of the cross sectional area circumscribed by the surface in the first cross sectional plane of the cavity, the casting surface directs each of the layers into the series of second cross sectional planes at relatively peripherally outwardly inclined angles to the axis. Then the surface allows the layer to assume second cross sectional areas whose cross sectional dimensions undergo continual enlargement peripherally outwardly of the axis, so that the thermal contraction forces arising in the layer can counterbalance the splaying forces while the layer freeforms with the other layers into a body of metal at one of the second cross sectional planes of the cavity.