Processing of Carbon Fibers Reinforced Mg Matrix Composites Via Pre-infiltration with Al (original) (raw)
Related papers
Journal of Materials Science, 2009
Magnesium matrix composites reinforced with SiO 2 coated carbon fibers have been investigated, with an emphasis given on the relation between the material strength and interfacial microstructure. The composites were studied as a function of aluminium (Al) content that is varied between 0 and 9 wt%. The obtained results indicate that the reactivity at the C/Mg-Al interface of the composite can be controlled by varying the Al content. The low Al content in C/Mg-1Al has been completely dissolved in the matrix with no segregation even after solidification, leading to the best mechanical performance. If the Al content is increased to C3 wt% (composites such as C/AZ31 and C/AZ91), the SiO 2 coatings are fully depleted due to an extensive formation of carbides at the interface. The precipitates are further identified as Al 2 MgC 2 phase that is similar to binary carbide Al 4 C 3 . SiO 2 coating on the fiber layer prior to fabrication of composite is found to be a promising way to suppress the carbide formation and enable the use of Mg-Al matrix with appropriate Al content.
2012
a anne.mertens@uclouvain.be, b aude.simar@uclouvain.be, c francis.delannay@uclouvain.be Abstract. Mg-Al-Zn alloys have been reinforced with carbon fibres using either the liquid state process of squeeze casting (SC), or friction stir processing (FSP), a solid state process developed more recently and that appears as a promising alternative for the large-scale production of C-Mg composites. Both processes have shown their ability to produce sound composites with enhanced strength compared to the non-reinforced alloys. In SC composites, the unsized woven C fabric remains intact while in the FSP composites the sized C fabric is fragmented in short fibres, with an aspect ratio typically equal to 4, homogenously distributed in the Mg alloy matrix.
Studies of the AZ91 magnesium alloy / SiO 2 -coated carbon fibres composite microstructure
IOP Conference Series: Materials Science and Engineering, 2010
The microstructure of magnesium matrix composite reinforced with SiO 2 nano-layer coated carbon fibres, deposited by sol-gel method was characterized. The composite was obtained by infiltration method and the effect of SiO 2 on the composite microstructure was analyzed by scanning electron microscopy combined with energydispersive X-ray spectroscopy (SEM+EDS) and transmission electron microscopy combined with energy-dispersive X-ray spectroscopy (TEM+EDS) methods. Good wettability of fibres by the magnesium alloy AZ91 (Al 9 wt%, Zn 0.3 wt%) was confirmed since fibres were closely surrounded with alloy and pulling-out effect was not visible. The interface region was evidently with aluminium enriched. Near carbon fibre surface a regular layer of SiO X oxide enriched with Al was detected by high angle annular dark field image (HAADF) combined with energy-dispersive X-ray spectroscopy (EDS). The plate or needle shaped very fine particles of Al 12 Mg 17 were identified near the AZ91 matrix zone by bright field (BF) and selected area electron diffraction (SADP).
Analytical and Bioanalytical Chemistry, 2002
Unidirectionally reinforced metal-matrix composites with a fibre volume content between 63 and 68% were processed by squeeze casting using T800 H carbon fibres and the magnesium alloy AZ91. The surface of the fibres was prepared by thermal desizing of the fibres or by deposition of a pyrolytic carbon (pyC) coating. Different interfacial conditions could be identified by transmission electron microscopy (TEM) and the single-fibre push-in test. TEM confirmed the formation of needle-like phases at the fibre surface or, for coated fibres, within the pyrolytic carbon coating. During loading by the Vickers type indenter an intense response was observed for composites of coated fibres and the magnesium alloy. This could by caused by stick-slip effects within the pyrolytic carbon coating.
Fabrication technology and material characterization of carbon fibre reinforced magnesium
Journal of Materials Processing Technology, 2006
Carbon fibre and textile reinforced lightweight materials with selected magnesium alloy matrices have been strongly considered nowadays for lightweight applications under complex dynamic and static operating loads, e.g. in automotive engineering. Thereby, especially continuous fibre reinforcement increases the application potential of this novel material group considerably.
Studies on 7075 Aluminium Alloy MMCs with Milled Carbon Fibers as Reinforcements
Transactions of the Indian Institute of Metals, 2017
Carbon in various forms (such as fibers, fabrics, sheet, nano tubes, particles and flakes etc.) have found use as reinforcements in metal matrix composites (MMCs) based on aluminium alloys. However, the literature available on AA7075 alloy based composites as well as on the use of milled carbon fibers as reinforcements is rather limited. This was the stimulus for the present work on carbon fiber reinforced AA7075 alloy composites. MMCs with varying volume content of milled carbon fibers were fabricated through Vacuum hot pressing, and were characterized for mechanical, thermal and electrical properties. Micro-structural aspects of these MMCs were studied using Optical microscopy, Scanning electron microscopy, transmission electron microscopy and X-ray diffraction. This was followed by a systematic assessment of the mechanical properties (viz., hardness and compression strength), and thermal and electrical conductivities. The influence of T7 heat treatment on the properties was also investigated. The composites thus produced exhibit uniform distribution of carbon fiber. No evidence has been found of the presence of aluminium carbide (Al 4 C 3) in any of the specimens. While the mechanical properties and electrical conductivity decreases as the amount of carbon fiber increases, thermal conductivity registers an appreciable increase in the In-plane direction. This appears to be the specific advantage of these carbon fibers reinforced MMCs, and is likely to open newer uses for this class of light weight materials.
Purpose: The aim of his paper is to show potential of textile-reinforced carbon fibre aluminium composite with advantage of the lightweight construction of structural components subjected to thermo-mechanical stress. Design/methodology/approach: The manufacture of specimens of the carbon fibre-reinforced aluminium was realised with the aid of an advanced differential gas pressure infiltration technique, which was developed at ILK, TU Dresden. Findings: The gas pressure infiltration technology enables to fabricate complex carbon aluminium composites with fibre or textile reinforcement using moulds of graphite, but in future development the optimization of infiltration process is required. The load-adapted combination of 3D reinforced semi-finished fibre products (textile preforms) made from carbon fibres (CF) with aluminium light metal alloys (Al) offers a considerable lightweight construction potential, which up to now has not been exploited. Research limitations/implications: Gas pressure infiltration technology enables to fabricate complex carbon aluminium composites with fibre or textile reinforcement using precision moulds of graphite, but in future development the optimization of infiltration process is required. Practical implications: Load-adapted CF/Al-MMC, due to the relatively high stiffness and strength of the metal matrix, allow the introduction of extremely high forces, thereby enabling a much better exploitation of the existing lightweight construction potential of this material in comparison to other composite materials. Originality/value: Constantly rising demands on extremely stressed lightweight structures, particularly in traffic engineering as well as in machine building and plant engineering, increasingly require the use of endless fibre-reinforced composite materials which, due to their selectively adaptable characteristics profiles, are clearly superior to conventional monolithic materials.
Fibre-matrix interactions during fabrication of Al2O3Mg metal matrix composites
Materials Science and Engineering: A, 1990
The reactions between alumina fibres and magnesium matrix in metal matrix composites at IO00K are investigated theoretically and experimentally. The diffusivities of aluminium in layers of spinel and magnesia are estimated and found to be exceedingly low. It is thus concluded that diffusional growth of such layers in the boundary between matrix and fibres will not occur during the casting of the composite. The reaction between amorphous SiOe binder and magnesium is further discussed and it is concluded that this may proceed at a considerable rate.