Polymer Ceramics Considered for Next Generation Body Armour
Lightweight body armour systems are typically made of high hardness, low density ceramic tiles. Ceramics are arguably the best material for this application as they have a high specific compressive strength and are very effective at blunting or in some cases fracturing projectiles. Despite its overall suitability, a number of challenges with many of the ceramics used in armour systems remain, including limited formability and poor multi-hit capability.
DMTC researchers at VCAMM and Deakin University are looking at alternative materials and systems in an effort to provide new solutions for body armour that can deliver both increased performance and reduced weight. One system under investigation is a material known as ‘Polymer Ceramics’. This material is an aggregate composite produced by infusing hard ceramic particulate with high modulus polymers and nano-technology. The resulting material has been shown to offer a number of advantages over traditional ceramics including low temperature processing, ease of moulding and extreme multi-hit performance. Even in these early stages of assessment the materials has been shown to achieve 80% of the ballistic performance of silicon carbide.
Recent work has focused on improving the interfacial adhesion between the ceramic and the polymer which is believed to be the primary driver of the overall ballistic performance of the composite. To improve the interface, a silane treatment has been developed that modifies the surface of the ceramic particulates at the nano-scale. In combination with a fluidised bed treatment, this nano-scale surface modification is akin to depositing nano-sized hairs on the surface and thereby increasing the area for adhesion. The silane treatment of boron carbide led to 35% higher yield strength at break and 24% increase in modulus compared to untreated formulations. It is anticipated that the improved yield strength and modulus through silane treatment will bring the material to within 90% of the ballistic performance of silicon carbide. The ultimate goal of the research is to achieve equivalent ballistic performance to silicon carbide and thus create a more cost effective and easily fabricated body armour material option.
