Apparatus for vacuum sintering and hot isostatic pressing

摘要

Apparatus for treating a workpiece at elevated temperatures both under vacuum and under superatmospheric pressures to provide for vacuum sintering and hot isostatic pressing in the same apparatus. The apparatus according to this invention comprises a vacuum-pressure vessel and a furnace within the vessel having a pedestal upon which the hearth rests extending up into the furnace. A first electrical heating means spaced about the pedestal is entirely below the hearth. At least one second electrical heating means is spaced about the workspace above the hearth. Means for separately controlling the first and second electrical heating elements are provided. The furnace can provide substantial uniform temperature distribution to the workpiece resting upon the hearth when the vessel is evacuated by direct radiation from the electrical heating means above the hearth. When the vessel is pressurized, uniform temperature distribution is maintained by convection from the electrical heating means below the hearth.