Metal-epoxy-matrix carbon-fibre hybrids for functional and structural applications
Topic(s) : Material science
Co-authors :
Hengli CAO (UNITED KINGDOM), Shimeng QIAN (UNITED KINGDOM), Emile GREENHALGH (UNITED KINGDOM), Xiaochuan SUN , Luiz KAWASHITA , Dmitry S. Ivanov (UNITED KINGDOM)Abstract :
We suggest new manufacturing method that enables creating metal-composite hybrids with rather unusual material architectures and set of properties. In these composites, metal matrix occupies inter-yarn space whereas the fibre bundles are impregnated with thermosetting matrix – Fig 1. This co-sharing of composite space offers a range of benefits both in mechanical and functional performance. Mechanically, it grants 15% improvement in strength of carbon woven composites when applied in close vicinity of stress concentrations. This is partly due to high stiffness and plastic yielding of metal matrix leading to strain redistribution mechanisms. Functionally, we see substantial (two-fold) reduction in resistive losses compared to co-infused electrodes, which is important for applications such as current collection or resistive heating. The boost of electrical properties occurs due to improved contact of metal with carbon fibres.
The hybrids are particularly attractive when metals introduced locally and in line with the philosophy of Multi-Matrix Continuously-Reinforced Composites (MMCRC) [1] – the hybrid domains are fibre-bridged with the composite infused with conventional matrices. Fibre bridging provides reliable integration of the hybrid patch with the hosting structure. When metal is added locally and tailored for specific function it does not provide significant weight penalties but offers a range of the material properties that polymer composites do not possess. The shape of the patches can be flexibly varied. One of our findings is that the shape of the patch is important when tackling stress concentrations.
The manufacturing of these hybrids involves application of inductive heating instrumented with novel cellular coils [2,3] and solved using the set-up similar to the one used in standard liquid moulding. The process is organised in two steps. In the first one, the metal is integrated into dry textile preforms. The processing hinges on tunning of process window to implement metal melting and preform impregnation before the heat reaches temperature-sensitive consumables. The process control and uniformity of the heat application can be steered to achieve various degrees of metal impregnation and composite morphologies – Fig 2. The second step involves conventional infusion process.
To the best knowledge of the authors, such composites architectures were never created before. We envisage a strong potential for this material configuration in both structural and functional behaviour of composite structures.
The hybrids are particularly attractive when metals introduced locally and in line with the philosophy of Multi-Matrix Continuously-Reinforced Composites (MMCRC) [1] – the hybrid domains are fibre-bridged with the composite infused with conventional matrices. Fibre bridging provides reliable integration of the hybrid patch with the hosting structure. When metal is added locally and tailored for specific function it does not provide significant weight penalties but offers a range of the material properties that polymer composites do not possess. The shape of the patches can be flexibly varied. One of our findings is that the shape of the patch is important when tackling stress concentrations.
The manufacturing of these hybrids involves application of inductive heating instrumented with novel cellular coils [2,3] and solved using the set-up similar to the one used in standard liquid moulding. The process is organised in two steps. In the first one, the metal is integrated into dry textile preforms. The processing hinges on tunning of process window to implement metal melting and preform impregnation before the heat reaches temperature-sensitive consumables. The process control and uniformity of the heat application can be steered to achieve various degrees of metal impregnation and composite morphologies – Fig 2. The second step involves conventional infusion process.
To the best knowledge of the authors, such composites architectures were never created before. We envisage a strong potential for this material configuration in both structural and functional behaviour of composite structures.