Developing protective vehicle armour with holes in it may not seem the most obvious way to increase protection for British troops on operations but that's just what MOD scientists are doing.
Since 2000, the Defence Science and Technology Laboratory (DSTL) at Porton Down in Wiltshire has worked in collaboration with Cambridge University and QinetiQ to develop Super Bainite, a unique ultra-hard armour material.
It may seem like a strange solution but introducing holes to vehicle armour can actually provide a protective advantage. DSTL scientist Professor Peter Brown explained:
"You shouldn't think of them as holes, you should think of them as edges. When a bullet hits an edge, it gets deflected, and turns from a sharp projectile into a blunt fragment - which is much easier to stop."
The introduction of holes also reduces weight he adds and doubles the ballistic performance, making perforated Super Bainite steel armour ballistically very efficient.
Invented, designed and manufactured in the UK, Super Bainite is an experimental high performance armour steel developed to save the lives of UK Armed Forces and the armour has performed well in ballistic testing at the Ministry of Defence's firing ranges.
Unlike conventional steels, the composition of Super Bainite was derived from first principles using thermodynamic modelling techniques. This allowed its processing, properties and cost to be optimised in months rather than years.
It has been know since the 1930s that certain heat treatments alter the fine-scale structure of steel creating a 'phase' called bainite, but in collaboration with steelmaker Corus, DSTL scientists have developed a new manufacturing process, which allows the alloy to be produced quickly and cost effectively.
Whilst other armour steels need to be quenched and tempered, Super Bainite develops its properties by a low temperature mechanism called isothermal hardening. This enables ultra-high levels of hardness to be achieved without having to use expensive alloying additions.
Isothermal hardening involves the steel being heated to 1,000C, cooled to about 200C, and then held at this temperature for a period of time before cooling to room temperature. This is how the Super Bainite develops its exceptional strength.
Traditionally the MOD has utilised offshore suppliers to fulfil its specialist armour requirements. However, following the successful industrial production trials, directed by DSTL in partnership with Corus and Bodycote, the UK is now well placed to develop a secure onshore supply of specialist, high hardness steel armour.
Professor Peter Brown added:
"Due to the unique process by which we have developed this new armour, Super Bainite is able to match the ballistic performance of the best off-shore armour steels at reduced cost."