Abstract: Apparatus for the physical vapor deposition of an alloy whose constituent ements have widely differing vapor pressures comprises an inner evaporation crucible (1) surrounded by a second evaporation crucible (2) having an array of nozzles (9) angled towards collector (5). In use of the apparatus, a charge (3) of relatively low volatility is evaporated from inner crucible (1) using an electron beam (7) focussed by magnet (8). Charge (4) in second crucible (2) is of much higher volatility and is evaporated by radiant heating. The nozzles (9) direct the vapor from charge (4) along pathways which intersect the vapor rising from charge (3) such that the combined vapor stream reaching collector (5) is an intimate mixture of constituents. The nozzles (9) may also serve to control the flow rate of vapor from the second crucible (2).

Abstract: In the production of alloy by evaporation from an evaporation bath and condensation under vacuum, charge replenishment is achieved by a procedure involving bleeding charge from the bath and admixing the bled charge with replenishment material and introducing replenishment from the admixture. An apparatus for use in the process comprises a mixing passageway encompassing an evaporation bath and distributed sub-surface bleed ports and feed ports linking the evaporation bath and the mixing chamber. Flow of metal through the ports is induced by pumped circulation in the mixing chamber. The circulation is turbulent for good mixing of the metals.