Continuous process for fabricating reaction bonded silicon nitride articles

摘要

Method of fabricating RBSN parts in which the processing of compacts of silicon to produce reaction bonded silicon nitride products is accomplished in a continuous style furnace. The furnace of the preferred embodiment is arranged as a contiguous series of furnace sections or zones configured to have a part conveyor traveling slowly from one end to another to sequentially expose the parts to each zone. Each zone may for example be one foot long. The conveyor then travels at a rate of one foot per hour. Parts to be nitrided are settered onto kiln furniture plates while providing a minimum one-quarter inch clearance to all other parts. The parts on the plates are conveyed through the sequential temperature zones in a continuous fashion while under ambient pressure flowing nitrogen gas. The parts travel through the contiguous temperature zones at a constant rate of conveyance allowing the nitriding reaction to progress to completion.