Abstract: Method and apparatus for producing a fine-grain ingot are disclosed. A feedstock stick is melted to produce a series of fully molten drops or a stream, which falls on the upper surface of an ingot being formed, to cover a portion thereof which is substantially less than the ingot's total upper surface. The mold is moved laterally with respect to the feedstock stick at a rate which is high enough so that the molten metal impinges upon different portions of the ingot's upper surface but which is low enough to prevent a substantial centrifugally outward flow of the metal impinging on the upper surface of the ingot. The molten metal melt rate is so selected that the impact region on the ingot's upper surface is at or below the solidus temperature of the alloy and above a temperature at which metallurgical bonding with the successive impinging metal can occur.

Abstract: A method is described for continuously casting an ingot of a metal alloy of a type having a substantial liquidus-solidus temperature range to produce internal microstructure of a desired fineness. Molten alloy is flowed along an electron beam heated skulled hearth while controlling the electron beam to maintain a solids content in the alloy on the hearth of between about 15% and about 40%. The alloy is poured from the hearth into the top of a continuous casting mold at a rate which produces a thixotropic region at the upper end of the fully solidified alloy in the mold. The ingot produced is characterized by a macrostructure in excess of one millimeter average grain dimensions with a non-uniform shape, orientation, and distribution, and is characterized by a microstructure of the order of fifty micron cell spacing of dendritic crystallites comprising the microstructure.

Abstract: A method is described for continuously casting an ingot of a metal alloy of the type having a substantial liquidus-solidus temperature range so that the ingot will have a "smooth" surface free of hot-tears. A succession of substantially equal volume quantities of the molten alloy is poured into a continuous casting mold at a pressure of less than about 10.sup.-3 Torr. The quantity of each pour is sufficient to cover the entire cross section of the mold by flow under the influence of gravity and each quantity is allowed to substantially solidify between pours to form successive axial increments which make up the ingot. Each increment is allowed to cool for at least about 30 seconds between pours to form a sufficiently solid side-wall to prevent hot-tears.