Scientists at Deakin University’s Institute for Frontier Materials have found a method for curving ballistics fibre, paving the way for creation of a new generation of combat armour.
In ballistics materials, the stiffness of the fibres makes it impossible to bend without wrinkling the material. Using a combat helmet as their model, the IFM researchers developed a unique process, which they called ‘double diaphragm deep drawing’ or D4, to curve and harden the Kevlar-style ballistic fibres into the correct shape.
Chief investigator, Dr Minoo Naebe and research engineer Madhu Suryanarayana worked with the Defence Materials Technology Centre (DMTC), Pacific ESI, Ballistic and Mechanical Testing and DSTO to develop the process.
They designed a special plant that uses heat forming to shear the fibres in ultra-high molecular weight ballistic fabric and managed to achieve perfectly shaped shells, 20-30 per cent lighter than current helmets.
The technology will help Australian industry deliver world class armour at lower cost to the Australian Defence Force and other military customers.
An important benefit of the D4 process is that it has eliminated the need to cut or splice the fibres, as in existing helmets, thus avoiding any compromise in strength, and improving the mechanical and ballistic performance.
Current standard issue ballistic combat helmets are made with a combination of spliced high tensile synthetic fabrics, such as Kevlar, and are put together by hand through expensive matched metal tooling. The process developed by the IFM researchers overcomes the need for intensive manual lay-up and enables the use of a range of high modulus fibre systems, including carbon fibre composites.
The helmet shells meet the highest safety standards and have passed stringent testing at Melbourne-based Ballistic and Mechanical Testing. During evaluation, they exceeded the specified US ballistics requirements and also passed anvil compression tests performed at Deakin, withstanding 1.7 kN of force from above and 1.3 kN from the side.
D4 is the world’s fastest composite forming process, taking only 20 minutes to produce each shell, compared to 45-60 minutes for current methods.
The process also has numerous other potential applications. It could be applied in areas as diverse as aerospace, automotive, shipping, construction, furniture, sports or radar covers (radomes).
The technology is ready to go and the team is looking forward to exploring commercial ventures with industrial partners.