FRACTURE STRENGTH OF LOW-PRESSURE INJECTION-MOLDED REACTION-BONDED SILICON-NITRIDE

Reaction-bonded silicon nitride (RBSN) samples were fabricated via a low-pressure injection-moulding technique. Sample batches of 58, 68, and 70 vol % silicon solids loading were moulded using a multicomponent, nonaqueous binder. These samples were analysed in terms of their nitrided bulk density, flexural strength, and microstructure. Bulk densities of 2.9 g cm-3 (91% theoretical density) and three-point moduli of rupture in excess of 304 MPa (44 x 10(3) p.s.i.) were achieved. These results indicate a potential use of low-pressure injection moulding as a forming technique for the fabrication of RBSN components.