公开(公告)号：US20080120889A1

公开(公告)日：2008-05-29

申请号：US11480639

申请日：2006-07-03

申请人： Animesh Bose ,  Robert J. Dowding ,  Jeffrey J. Swab

发明人： Animesh Bose ,  Robert J. Dowding ,  Jeffrey J. Swab

IPC分类号： F41A21/04 ,  B22F3/02 ,  B22F5/12

CPC分类号： F41A21/20 ,  B22F3/225 ,  B22F5/085 ,  B22F2998/00 ,  B22F2998/10 ,  F41A21/18 ,  C22C29/08 ,  B22F3/1025 ,  B22F2202/03 ,  B22F3/15 ,  B22F3/10 ,  B22F3/1035

摘要： Gun barrels made from advanced materials have the potential to provide a significant increase in barrel life as well as a reduction in weight (for advanced ceramic materials) for small caliber systems. The potential use of advanced materials as gun barrels is severely limited due to the difficulty in introducing the rifling pattern on the inner diameter. Most projectiles coming out of the guns are spin stabilized (for aerodynamic flight stability). This spin is imparted by a rifling pattern (lands and grooves) in the inner surface of the gun barrel. The processing of gun barrels made from advanced materials with internal rifling pattern poses a tremendous processing challenge to the materials community. The rifling lands and grooves and desired twist rate coupled with the difficulty of machining some of the advanced materials (ceramics, cermets, hardmetals, etc.) makes the economic manufacturing of such gun barrels extremely difficult. Currently, this form of rifling is achieved by machining in case of metallic gun barrels.The limitation in producing the rifled pattern lies with the conventional processing of complex shaped advanced materials such as ceramics, cermets, or hardmetals. Shaping of these typically requires careful diamond grinding. This grinding process is not only very expensive but it also introduces flaws in case of the brittle ceramics (microcracks). These flaws are detrimental to the performance of these advanced materials as rifled gun barrels. Thus, there is an opportunity and challenge to the materials community to come up with a processing solution that will allow advanced materials such as silicon nitride (Si3N4), SiAlON, hardmetals, etc. to be used as gun barrels that have the rifled pattern in the inner diameter.Herein are provided methods and compositions useful to form the rifled gun barrel tubes from advanced materials using little or no machining of the internal rifled geometry.