Specifications include, but are not limited to: The furnace must include the following features and meet the following specifications: Formfactor: The furnace must be floor-standing and will have floorspace of up to 8 feet x 8 feet available. Basic layout: In basic terms, this furnace should be comprised of the following elements: Stainless steel vacuum chamber with an all-metal top-loading hot zone, power supply, heating controls and temperature sensing, vacuum system and controls, argon backfill system and controls, and water cooling system. Hot zone: The hot zone shall be all metal and top-loading. The useful hot zone size (i.e. effective volume available to heat-treat specimens) must be 5.5 inches or 6.0 inches in diameter and 5.0 inches to 6.0 inches tall. It is understood that the overall hot zone will be larger than the above useful hot zone size, firstly to ensure a sufficient gap between the specimens, the heating elements, and the heat shields, and secondly to ensure good temperature uniformity throughout the useful hot-zone volume. The resistive heating element type must be tungsten-mesh or tungsten-weave. Towards the side, bottom, and top, the hot zone must have multiple layers of refractory metal heat-shielding. In line with the typical layout of such furnaces, the heat-shielding should feature at least four layers of tungsten shields, followed by at least three additional layers of molybdenum shields towards the outside, where each shield layer should typically be at least 0.005 inches thick. More shield layers should be added as the vendor considers most appropriate for optimal lifetime, temperature control, and temperature homogeneity...
