Method for making a composite fragmentation cap that is integrally formed onto a projectile body
Process for making a fragmentation warhead using hot isostatic pressing where tungsten spheres, powdered steel, and interlock features on a mandrel are consolidated in a matrix. Then in the finished part, the front fragmentation cap, rear and interior geometries are machined, resulting in a finished warhead with an enhanced performance fragmentation cap integrally bonded to it.
1. A process for making a fragmenting warhead liner attached to a nose of a selected ammunition round comprising the steps of:
a) forming a wrought steel body shaped like the round being outfitted with said fragmenting liner,
b) forming a hollow cylindrical canister to enclose said wrought steel body, said canister having a defined bottom thereon,
c) welding on a bottom sealing cap at the bottom of said canister to seal it,
d) filling the canister with uniform tungsten spheres as fragmentation preforms,
e) filling any spaces between the spheres with powdered 4340 steel to serve as binder material,
f) welding on a top sealing cap which also includes a stem which can be selectively used to create a vacuum within the canister,
g) applying a vacuum at the stem and heating the canister for purposes of degassing the canister,
h) crimping the stem shut and welding it in a crimped position,
i) applying a hot isostatic pressing (HIP) process to solidify the said binder material around and chemically bond it to the wrought steel body, while also solidifying a matrix of the tungsten spheres, closely packed and suspended within the solidified binder material,
j) cutting off all or part of the canister and of the top and bottom sealing caps, which results in forming a composite part, and
k) machining the composite part to a desired geometry.
2. The process for making a fragmenting warhead as in claim 1 wherein the composite part, rear and interior geometries are machined, resulting in a finished fragmenting warhead with an enhanced performance fragmentation cap integrally bonded to said fragmenting warhead.
3. The process for making a fragmenting warhead as in claim 2 wherein between steps a) and b), mechanical interlock features are first included on an outer profile of the wrought steel body, to strengthen the bond between the wrought steel body and the fragmentation cap.
4. The process for making a fragmenting warhead as in claim 3 wherein the composite part, rear and interior geometries are machined, resulting in a finished fragmenting warhead with an enhanced performance fragmentation cap integrally bonded to said fragmenting warhead.