Engineers at Surrey University and Lockheed Martin UK are working on a project to develop appliqué vehicle armour that can withstand multiple ballistic strikes.
Andrew Harris, an engineering doctorate research engineer at Surrey, explained that ceramic armour is used on many light-armoured vehicles because it is as effective as metal and can withstand a number of threats, particularly bullets.
Another advantage of ceramic-based shielding is that it is lightweight — an important consideration given that armour can account for half of a vehicle’s mass.
Harris explained that, despite its advantages, ceramic armour possesses a flaw that has been a problem for a number of years.
‘A very basic ceramic armour would be a very hard front-face material such as alumina or silicon carbide that is bonded to an energy-absorbing backing material, typically a composite fibre or metal that absorbs the energy of the fragments,’ he said.
‘When you get a bullet impact, it transmits a lot of energy into the ceramic and that shock causes the ceramic tiles to come off the backing material, which makes the ceramic armour only good for one hit. You can get around this by over-designing the ceramic armour, making it heavier. What we’ve done is improve the bond strength; we tested it and found that the armour performance is improved.’
The team has developed a proprietary method of treating the adhesive and pre-conditioning ceramic surfaces prior to bonding, which has led to an improvement in armour integrity.
‘We are currently in the position of having proven the multi-hit capability of the bonded ceramic armour,’ said Steve Burnage, head of design at Lockheed Martin UK. ‘In doing so, we now need to optimise the treatment of the surface of the ceramic, in terms of minimising preparation time and therefore cost, for optimal performance.’
Once this is established, Burnage expects discussions to take place with ceramic armour manufacturers to further develop this process for commercial quantities — ‘the objective being to have lighter, more durable and effective armour systems for both vehicles and personnel body armour’, he said.