Sialon for Monolithic Ceramic Gun Barrel Liners

The ceramic ß′ Sialon (Si3Al3O3N5) has the potential to become a paradigm in gun barrel liners providing increase barrel life, accuracy, nuzzle kinetic energy and produce considerable weight reduction. The ß′ Sialon is a single phase ceramic which can be readily sintered free of glassy grain boundaries with exceptional properties in fracture toughness, hardness, strength and thermal shock resistance. Based on previous demonstrated production of many ß′ Sialon components including 1220mm long bow free tubes, this Phase I has reconfirmed the exceptional properties as well as produced tubes up to 500mm long. In-situ rifling has been demonstrated in the ß′ Sialon tubes. The Phase II program will build upon the Phase I results to demonstrate one and two meter long ß′ Sialon tubes which are free of bowing with a 24mm ID by 33mm OD with a tolerance of ± 0.15mm cylindricity. The in-situ rifling will also be developed in the one and two meter long tubes with demonstration tubes delivered to the Army. The previous production of over one meter ß′ Sialon tubes and the success in Phase I provides high certainty for success in producing one and two meter long tubes that meet specifications.