Ionitech - Cold-Wall Plasma Nitriding and Low Temperature Nitrocarburising Equipment
From Cold-Wall Equipment
The heating of the parts, in a Cold-Wall plasma nitriding installation, is carried out only by pulsed plasma created in the vacuum chamber. This type of plasma nitriding equipment is especially suitable for nitriding similar in shape and size batches of parts. The main advantages of this type of equipment are:
- Lower cost of the equipment
- Easy maintenance
- Lower consumption of electrical energy
The Cold-Wall vacuum chambers’ type could be:
- Door-type chambers
- Bell-type chambers
- Pit-type chambers
- Combined chambers loaded from the bottom and from the top
The vacuum chambers have double walls, with cooling water circulating in between. In order to decrease the heat exchange between the treated parts and the chamber walls. Two stainless steel shields, separated by thermo-insulating wadding, are installed on the inside surface of the walls and the bottom.
In the door-type chambers and bell-type chambers, the parts are loaded on a metal plate. In the pit-type chambers the parts are attached to special devices to hang. And for the combined-type chambers, the parts could be loaded on a working plate or attached to devices to hang. The metal plate and the special devices for attachment lie on support insulators and are connected to the cathode of the plasma generator. The process of plasma nitriding could be viewed through a sight glass. The temperature during the process is measured directly in the parts using one or two thermocouples K-type.
The plasma generator and it’s defense mechanism - a power transformer, a three phase thyristor rectifier, a power choke, a power IGBT switch and a number of circuit breakers, filters and contactors, assembled for different supply voltages and mains frequencies. They are mounted in metal cabinet IP 54 that is cooled with an air conditioning.
The gas vacuum system evacuates the chambers and fills them with treatment gases. It includes a vacuum pump, electro-pneumatic and electromagnetic valves, reducing valves with filters and manometers, mass flow controllers, gas mixer, manual valves, two absolute pressure gauges and vacuum connections.
The pressure gauges are mounted on the chambers bodies. The rest of the components are placed in a ventilated metal enclosure IP54. The process is carried out with a mixture of hydrogen and nitrogen. Propane or natural gas are used for nitrocarburising. After the end of the treatment, the chambers can be filled with argon for accelerated cooling. Pressed air is used for the operation of the electro-pneumatic valves.