Silicon nitride parts from selective laser-sintered silicon

Silicon nitride is a ceramic used in wear and high temperature applications. Silicon nitride parts are made by pressing silicon powder into a generic shape such as a block, reacting the silicon with nitrogen in a furnace, then post-processing the block by grinding and cutting to obtain the final desired shape. The selective laser sintering process can eliminate post processing by allowing construction of complex shapes prior to firing in a furnace.; The Selective Laser Sintering (SLS) process is a prototyping process that builds a part from powder, layer by layer, fusing each layer of powder to the layer below it until the part is complete, The selective laser sintering process currently incorporates thermoplastics, such as nylon, or a steel powder mixed with a binder. Silicon powder can be mixed with a binder and used in the selective laser sintering process in much the same manner as a steel powder is used.; Silicon powder is mixed with a binder and used in the selective laser sintering process to create green parts. These parts can then be nitrided in a furnace in the presence of nitrogen to produce silicon nitride parts. Silicon nitride test bars and a silicon nitride complex geometry part were successfully produced by construction of silicon green parts in the selective laser sintering process.