Chamber and Hot Zone
The chamber is loaded from the front and contains a Hot Zone with a 3.0″ diameter x 6.0″ high usable zone and +/- 10°C temperature gradient. The heating element is a 1/2- 1/2 split design allowing the die body to be inserted straight into the zone. The furnace chamber is manufactured from double-walled stainless steel welded together and polished for a clean finish and good vacuum integrity.
The hot zone assembly can be one of three choices: a graphite band element and rigid fibrous graphite insulation pack, a Moly-D rod element and ceramic insulation pack, or a high temperature metal mesh heating element and layered metal shielding. In the hot press configuration the maximum operating temperature is 2300°C (1650°C with a ceramic zone). With the end plug shields supplied to plug the top and bottom hot rod openings, the furnace can be used as a batch/sintering furnace with operation temperatures to 2600°C.
Hydraulic Press
The Post and Platen Press Frame with load train is designed and manufactured to withstand well over 10 tons of force. This Post & Platen Frame is fully adjustable in all directions. Unlike the standard welded “H” frame, this MRF design supports the chamber totally free of the load train and is fully adjustable. The support includes, four (4) independent post clamp collars, a top platen supporting the top-mounted hydraulic cylinder, bottom platen supporting the lower dead rod, and adjustment bolts for the clamp collars and cylinder flange. The load train includes water-cooled stainless steel top and bottom cold rods, and high-strength top and bottom hot rods. The top rod has a 4.0″ stroke and the top cold rod is sealed by a static o-ring on a bellows assembly to provide a vacuum seal.
The Servo Hydraulic and Pressure Control System includes a 4.0″ stroke hydraulic cylinder, a hydraulic power unit, a pressure gauge to monitor hydraulic fluid pressure, and a load cell to measure and control pressforce. The pump size and servo valve are sized to allow a high cylinder speed for initial positioning, loading and unloading. Cylinder positional accuracy is0.001″ and press force accuracy is 1 lb. Manual jog buttons are included on the PC to allow for manual control of the top ram for loading and unloading a specimen.
Power Supply & Controls
Power to the hot zone is supplied by a three-phase SCR-controlled power supply, including a circuit breaker, a contactor, an SCR to modulate the power to the hot zone, and a step-down transformer matched to meet the heating element resistance. Volt and Amp Meters allow visual observation of power usage, and a set of water-cooled power cables supplies power to the furnace.
Temperature and press control is accomplished either with classic instruments and push buttons, or by means of a Programmable Logic Controller (PLC) and Industrial Computer with HMI. The PLC is used to control temperature, force (to 1 lb accurate) or displacement (travel to 0.001″ accurate), and other system components such as vacuum and gas. The press forceand temperature control programs can be synchronized. Since the PLCreads and controls travel, temperature, and press force, other instruments can be eliminated thus simplifying operation and configuration.
The controller interfaces with the PC and transmits the temperature, power, force, travel, vacuum and force readings. This instrument also controls all digital logic required to control the solenoid valves, motor starters, interlocks, hydraulic system and vacuum system. The HMI system logs data, displays graphs, alarms, and provides an intuitive easy-to-use graphical interface for full furnace control.
A type “C” sheathed and coated thermocouple is supplied and can be used to measure the furnace temperature up to 2000°C. When operating the furnace to temperatures above 2000°C, control is automatically switched over to a Pyrometer.
Vacuum and Gas System
The evacuation system consists of a Rotary Vane mechanical pump, an electro-pneumatic vacuum valve, vacuum gauge controller and vacuum gauge. This vacuum system will allow for operation in a vacuum environment (10-2 Torr range). A 4″ or 6″ diffusion pumping system or a turbo pumping system can be provided as well and can achieve vacuum levels down to 10-6 (diffusion pumping system) and 10-7 Torr range (turbo pumping system). A manual valve is provided for leak checking or air releasing the roughing line.
The gas system is supplied to provide an inert environment for the work samples during the heating and pressing. The process gas system (Argon) includes a solenoid-operated inlet valve, a compound gauge (30 P.S.I.G. x 30 in. Hg.), a gas flow meter, and a 2 P.S.I.G. outlet relief valve to maintain a positive pressure. There is also a 5 P.S.I.G. over-pressure safety relief valve.
Water Cooling system
The furnace water cooling manifold consists of multiple circuits to adequately cool all the furnace parts and includes a strainer, pressure regulator, pressure gauge, water inlet and outlet manifold, a water flow switch as a visual water flow indicator with a flow interlock to protect the furnace in the event of a water flow failure. This switch turns off power to the hot zone if water flow is below recommended minimum for a certain amount of time. Each part of the furnace is supplied with a separate cooling circuit that can be regulated by independent manual ball valves.
Utilities
| Power: | kVA dependent on max temperature rating, 380-480 V/3/50-60 Hz (other voltages available). |
| Water: | 70F (20°C) and 50 P.S.I.G. (3.4 bar), required flow dependent on kVA rating. |
| Process Gas: | Argon or Nitrogen 30 L.P.M. @ 50 P.S.I.G. |
| Compressed Air: | 60 – 90 P.S.I.G. (4.1 – 6.2 bar) filtered. |
