High-temperature Chamber Furnaces & Tube Furnace

For production sintering operations, certain furnace design considerations are common regardless of whether you are working in metals, ceramics, or glass and regardless of what industry you work in. In order to achieve compression without liquefication, accurate temperature control and careful atmosphere monitoring are essential to uniformity and throughput.

Typically, the higher-temperature continuous furnaces used for sintering operations are known as “pusher furnaces” or “walking-beam furnaces.” A pusher furnace moves the work through on a series of boats or plates. One boat is pushed against another in a continuous train. A pusher furnace only pauses long enough to remove a boat at the exit end and add one at the entrance end. This is considered a constant push.

A walking-beam furnace utilizes a pusher mechanism to bring the boat into the furnace and place it on the beams. These beams are analogous to a series of rails. The rails are on cams, which lift up, forward and down, essentially walking the boat or carrier through the furnace. At the exit end, the boats are then commonly transferred onto a belt for the cooling section.

A tube furnace is an electric heating device used to conduct syntheses and purifications of inorganic compounds and occasionally in organic synthesis. One possible design consists of a cylindrical cavity surrounded by heating coils that are embedded in a thermally insulating matrix. Temperature can be controlled via feedback from a thermocouple. More elaborate tube furnaces have two (or more) heating zones useful for transport experiments. Some digital temperature controllers provide an RS232 interface, and permit the operator to program segments for uses like ramping, soaking, sintering, and more. Advanced materials in the heating elements, such as molybdenum disilicide offered in certain models can now produce working temperatures up to 1800 °C. This facilitates more sophisticated applications. Common material for the reaction tubes include alumina, Pyrex, and fused quartz.

The tube furnace was invented in the first decade of the 20th century and was originally used to manufacture ceramic filaments for Nernst lamps and glowers.

Soutrce:https://www.sukoptfe.com/high-temperature-chamber-furnaces-tube-furnace

High-temperature Vacuum Sintering Furnaces

Vacuum sintering, refers to the process that making the powder material into dense material in the condition of the vacuum.People use this process to produce ceramics, powder metallurgy, refractories, ultra-high temperature materials.

In general, after forming the powder and by the sintering process, it becomes the density mateiral.The sintering process directly affects the grain size, pore size and grain boundary shape and distribution in the microstructure, thus affecting the properties of the material.

These furnaces are equipped with electrical resistance heating or with inductive heating. They can be used for numerous purposes because they apply vacuum as well as inert atmospheres. This main application is debinding and subsequent sintering of ceramics or powder metallurgical parts.

They are also used for different high - temperature processes such as carburisation, recrystallisation, silicon infiltration, nitridation (formation of Si3N4), vacuum sintering or metallisation.
Available volume: 1 dm³ to 10 m³ at max. temperatures of 2800 °C.

Examples for materials that can be processed in FCT furnaces are:

• Composite materials, MMC and CMC material
• Reaction bonded silicon nitride and nitride bonded silicon carbide used in various high temperature applications such as welding nozzles and fixtures, components for aluminium founderies, kiln furniture etc.
• Sintered silicon nitride and sialon (parts for mechanical applications at high temperatures, e.g. wear parts, motor components etc.)
• Reaction bonded silicon carbide SiSiC (e.g. axial face seals, composite materials, kiln furniture etc.)
• Pressureless sintered silicon carbide (parts for high performance applications at high temperatures or in severe environments).
• Hard metals (WC, TaC, TiC, NbC) with a metallic “binder” such as Co or Ni.
• Refractory metals: metals with very high melting points, like W, Mo, Ta, Nb etc.
• Advanced kiln furniture based on SSiC, RSiC, SiSiC, NSiC and composite materials.
• Rare-earth-metal-alloys e.g. samarium-cobalt or neodym-boron-iron, as high performance permanent magnets

Other high performance materials which are used at very high temperatures and very high pressures.