Tungsten Alloys for Ammunition and Other Components

Modern anti-tank warfare requires a special type of long rod penetrator core to be made out of as heavy and strong an alloy as practically feasible. Tungsten is one of the heavier metals available, with density 19.3 g/cc, which makes it ideal for Kinetic Energy (KE) penetrators. However, due to its high melting point (3440 °C), tungsten can only be processed by powder metallurgy route. When suitably alloyed with nickel and iron, it can be formed into a requisite shape through a powder processing technique at a temperature as low as 1500 °C. Indigenous technology for KE penetrator in anti-tank ammunition has been established at DMRL and productionised at Heavy Alloy Penetrator Plant (HAPP), Tiruchirapally.

This technology has also been extended to the production of pre-fragments for missile warheads and ballasts to meet the requirements of systems laboratories. HAPP is currently producing Fin Stabilised Armour Piercing Discarding Sabot (FSAPDS) Mk-II penetrator, pre-fragments and ballasts. DMRL is working on improved versions of FSAPDS ammunition material in association with ARDE and HAPP.

A nother version of the penetrator uses an alloy steel core instead of heavy alloy. Persistent R&D efforts at DMRL have led to the development of a superior substitute alloy with significantly improved properties compared to the originally imported material. In addition, two other parts of the penetrator assembly, namely the sabot and the tail units, have been developed via closed-die forging and star-shape extrusion routes, respectively with input material savings as high as 45 per cent for the sabot and 85 per cent for the tail unit. For this trio of armament parts, transfer of bulk production technologies has also been completed.