Squeeze Casting 81mm M374 Mortar Body and 155mm M483 Projectile Body Preform

摘要

The project described in this report demonstrates the feasibility of squeeze casting two specific munitions components: the 81mm M374 mortar body and a preform for the 155mm M483 projectile body. Squeeze casting is a hybrid of conventional casting and forging techniques which involves one-step conversion of molten metal into near net-shape components or preforms. Also termed 'liquid metal forging,' this process involves pouring molten metal into metallic dies in a hydraulic press and solidifying the metal under high hydrostatic pressure through the application of direct press tonnage. In this program, both pearlitic malleable iron and ductile iron were evaluated for squeeze casting of the mortar body. Ductile iron proved to lend itself better to squeeze casting and was selected for optimization studies. The preform for the 155mm M483 body was squeeze cast from 1340 steel. The first phase of the program involved optimization of process parameters to produce consistently sound squeeze castings. The second phase examined the reproducibility off squeeze casting the mortar body through a 'pilot production' run which employed the optimized process parameters established in phase one. Both phases have been completed successfully and are described in this final report together with cost estimates for squeeze casting the mortar body on a production basis.