Sintering Furnaces

Vacuum Annealing Furnace

The majority of the vacuum furnaces manufactured worldwide are used for processing steel alloys, with smaller market segments for nickel, titanium, aluminum and other metallic alloys. Vacuum brazing furnaces make up a significant portion of these furnaces. Various metallurgical heat treatment processes performed at temperatures below 1200 C or so make up the largest portion of this market.

he complexities of the iron-carbide phase diagram creates a wealth of opportunities for modifying metallurgical and physical properties of steel alloys. Annealing is a commonly used process that involves raising the material to an elevated temperature to increase the atomic diffusion rate, curing lattice defects, and improving component ductility.

Steel alloys are the materials most commonly annealed. However, many metallic and ceramic materials can benefit from elevated temperature annealing to relieve internal stresses created by fabrication and forming processes. Vacuum annealing furnaces fall into 2-3 broad categories based on the material being processed. Annealing furnaces for iron and nickel alloys are generally limited to temperatures below 1200° C. Annealing furnaces for ceramic materials more commonly have maximum use temperatures approaching 2000° C. Recently, there has been a third category: annealing furnaces for carbon-based nanotubes with processing temperatures that sometimes exceed 2000° C.

Common annealing atmospheres range from air to inert gasses to reducing gases. They are dependent on the nature of the application and requirements for post-anneal processing and component finishing. The most demanding applications use vacuum annealing that provides clean surface finishes without oxide scale, and require minimal to no post-anneal processing.

The following figure shows the RD-M, a widely used benchtop vacuum annealing furnace manufactured by Webb Vacuum Furnaces. It can be used to process coronary stents and other medical devices.

RD-M Annealing Furnace

RD-M Vacuum Annealing Furnace