In the railway industry, and premium luxury and super sports sectors of the automotive industry, traditional cast iron brake discs are gradually being replaced with advanced composites such as carbon fibre reinforced carbon silicon carbide (Cf/C-SiC). These materials offer the ability to operate at higher temperatures, whilst displaying improved friction performance, and vastly reduced wear rates. Their primary benefit comes from being approximately one third of the density of the incumbent material used in the industry, grey cast iron (GCI), a cast iron with a high proportion of graphite flakes formed during solidification. This reduced density means that brake discs manufactured from Cf/C-SiC materials are a highly suitable proposition for a future automotive market, where weight saving in an attempt to meet ever restrictive CO2 emissions is a must. The understanding surrounding the friction mechanisms involved with these new materials has been lacking, until recently, with the majority of the international research focused on the manufacturing methods. Research has shown that friction performance, particularly bedding friction, is highly dependent on the successful formation of a friction transfer film (FTF) at the surface of any disc, comprised from wear debris from both the disc and pad. Prior research carried out at Loughborough University has identified that Cf/C-SiC materials do not readily form such a layer, as might be seen on a GCI equivalent, due to the intrinsically heterogeneous nature of the composite material.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:763414 |
| Date | January 2013 |
| Creators | Swarbrick, Arthur L. |
| Publisher | Loughborough University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://dspace.lboro.ac.uk/2134/15055 |
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