Bell furnace is a kind of heat treatment furnace, which consists of a heating mantle, two movable furnace seats, two inner mantles and a valve frame. The heating mantle is made of steel plate rolled into a circle and welded. Ion Nitriding vs Gas NitridingOn the upper part of the mantle body there is a position for hoisting and changing the mantle, on the lower part there are three supporting feet for supporting the furnace mantle, and at the bottom there is a sand-sealing knife, which is used during heating. Sintering of B4C by Pressureless Liquid Phase SinteringThe heating mantle can be directly pressed on the flange of the furnace inner mantle to achieve a sealing effect. The furnace cover is sealed with the furnace body through the supporting feet and the sand sealing knife, while the inner cover is sealed with the furnace cover through the supporting feet and the sand sealing knife. The furnace cover is also equipped with a cylinder-driven mechanical seal mechanism, which achieves the sealing effect by pressing the sealing surface between the furnace cover and the inner cover, and injecting nitrogen into the seal. Vacuum Heat Treatment of FastenersThe bell furnace has the advantages of uniform heating temperature, accurate temperature control, energy saving, less environmental pollution, quick start-up and quick stop of the equipment, and can be used for vacuum, positive pressure or atmosphere treatment, but the equipment is huge, the sealing mechanism is complex, and the maintenance volume is large. ,costly.Vacuum sintering of transparent ceramics