Novel materials for cars and planes
In contrast, a functionally graded material (FGM) is a composite designed such that the composition varies (it is graded) throughout the volume in a way that adds functionality (hence, functionally). For example, a designer might strive for strength at one edge of a material gradually changing toward malleability at the other edge. A European consortium is seeking to exploit novel metal-ceramic FGMs with EU funding of the 'Micro and nanocrystalline functionally graded materials for transport applications' (Matrans) project. Scientists are developing FGMs targeted for use in exhaust and propulsion systems, power transmissions and braking systems. Use of FGMs in these components is expected to provide significant performance enhancements compared to conventional materials. Matrans is focused on two broad groups of ceramic-based (aluminium oxide (Al2O3)) FGMs, the first being ceramics-copper/copper alloys and the second ceramics-intermetallics (nickel aluminide (NiAl)). The former are geared toward thrusters (low content of Al2O3) and brake disks (high content of Al2O3) and the latter for valves. To date, the aforementioned materials have not been used in the specific applications. The scope of the project includes the preparation of the starting materials (powders, cast foils and preforms), the processes applied to achieve the resulting FGMs and processing to produce the final part. The first two years have focused on the starting materials and processing of the composite layers for the FGMs, including characterisation of properties and microstructure as well as modelling work. To date, scientists have produced demonstrators made of FGMs for all three applications. matrans has delivered new design concepts for aerospace and automotive components based on metal-ceramic FGMs. Enhanced performance and durability will contribute to longer part lifetime with lower costs.
