Sensors measure magnetic field components, and the measured fields are used to calculate and estimated transverse position of a longitudinal electric current flowing as an electric discharge across a discharge gap. Based on the estimated position, and according to a selected transverse trajectory or distribution of the estimated discharge position, magnetic fields are applied transversely across the discharge gap so as to control or alter the estimated discharge position. Inventive apparatus and methods can be employed, inter alia, during operation of a vacuum arc furnace.

A method for forming large titanium parts includes forming bends into a titanium plate for form a bent part. The bent part is then roll-formed to form contours into the bent part. The surfaces of the contoured part are rough-machined, and the part is then secured to a bladed form fixture. The bladed form fixture comprises a plurality of header boards that secure the part to the fixture. The fixture part is placed in a thermal vacuum furnace and a stress-relieving operation is performed. The part is removed from the fixture and final machining takes place.

A method for making covetic metal-carbon composites or compositions by electron beam melt heating under vacuum (pressure <10.sup.3 Torr) is described herein. This fabrication method is advantageous, in that it provides oxygen-free covetic materials in a process that allows precise control of the composition of the covetic material to be produced. The method described herein also can be applied to produce multi-element-carbon composites within a metal or alloy matrix, including high melting temperature materials such as ceramic particles or prefabricated nano- or micro-structures, such as carbon nanotubes or graphene compounds. The covetic reaction between metal and carbon takes place under the influence of flowing electrons through the melted metal-carbon precursor. This process creates strong bonding between nanocarbon structure and the metal elements in the melt.

A hydrogen, lithium, and lithium hydride processing apparatus includes a hot zone to heat solid-phase lithium hydride to form liquid-phase lithium hydride; a vacuum source to extract hydrogen and gaseous-phase lithium metal from the liquid-phase lithium hydride; a cold zone to condense the gaseous-phase lithium metal as purified solid-phase lithium metal; and a heater to melt the purified solid-phase lithium metal in the cold zone and form refined liquid-phase lithium metal in the hot zone.

A control system for a vacuum arc remelting (VAR) process for a metal includes a direct current (DC) power source, a ram drive, voltage drip short sensor, and a controller, which includes a processor. The drip short sensor may be configured to measure a drip short frequency of the electric arc over a period of time. The controller is configured to determine a real time arc gap length between the electrode tip and the melt pool based on a correlation between the drip short frequency and arc gap length. The controller is further configured to control power input to the electrode by the DC power supply by determining an input power level to input to the electrode based on the real time arc gap length, the input power level configured to generate a desired arc gap length, by the DC power supply, at the input power level.

A high temperature vacuum furnace including a prefabricated tongue-and-groove, low-mass insulation ring assembly hot zone, resulting in decreased energy costs and increased energy efficiency, faster heating and cooling cycles, and expedited maintenance capability resulting in lower maintenance costs. Decreased time of a workpiece in the furnace improves production turnaround and lowers energy costs for each heat treating cycle. Furnace manufacturing is also easier and less expensive compared to prior art vacuum furnaces. A bottom support structure replaces the prior art metal support ring resulting in an approximately 80-85% weight saving in the furnace hot zone. This reduces the time and energy required to heat and cool the furnace components and workpiece.

Example systems include a vacuum chamber enclosing a pouring cup and a platform configured to support a casting assembly. The casting assembly is configured to hold a plurality of joinable components and a mold defining at least one mating groove configured to join at least two joinable components of the plurality of joinable components when occupied with a metal or an alloy. Each respective mating groove is fluidically connected to a respective surface opening of a plurality of surface openings defined by the mold. The pouring cup and the respective surface opening are movable relative to each other by moving at least one of the pouring cup or the platform supporting the casting assembly to substantially align the pouring cup with the respective surface opening. The pouring cup is configured to pour a respective volume of molten metal or alloy in at least two surface openings.

There is provided a measurement apparatus for a vacuum furnace, comprising a data acquisition device, comprising a sensor interface operable to electrically couple one or more sensors to the data acquisition device, and a thermally conductive layer disposed on a first surface of the data acquisition device and to provide a thermally conductive interface between the first surface of the data acquisition device and a cooled internal surface of the vacuum furnace.

A method of vacuum arc remelting an ingot provided in a crucible assembly having an electrode includes generating a rotating magnetic field normal to a longitudinal axis of the ingot and localized to an arc region during remelting. The rotating magnetic field interacts with a melting current to produce a rotating arc directed radially outward.

An integrally-formed metal-casting mold loaded with a solid-metal ingot in an ingot-cup portion thereof is heated in a furnace under vacuum to a temperature sufficient to melt the solid-metal ingot. The ingot-cup portion is operatively coupled to a component-mold portion of the mold via a funnel portion thereof, either directly or through a riser portion operatively coupled to a base of the component-mold portion, which provides for feeding molten metal melted from the ingot to cast a part in the component-mold portion. Molten metal in excess of what is needed to cast the part flows either into the riser portion, or into a fluid conduit that extends above the component-mold portion. The molten metal may be fed to the component-mold portion through a molten-metal filter to reduce flow rate or remove contaminants. The mold may be formed either as an investment mold or directly by additive manufacturing.