Production and forming of structure aluminium composites with assumption a distribution of reinforcement
Anna Dolata - Grosz*, Józef Śleziona*, Jakub Wieczorek*, Krystyna Pietrzak** *Politechnika Śląska, Wydział Inżynierii Materiałowej i Metalurgii, ul. Krasińskiego 8, 40-019 Katowice **Instytut Transportu Samochodowego, ul. Jagiellońska 80, 03-301 Warszawa
Annals 3 No. 6, 2003 pages 125-130
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abstract Particle aluminium metal matrix composites have found applications within the aerospace, military but especially in the automotive industries [1]. In general, these materials exhibit good wear and erosion resistance, higher stiffness, hardness and strength, at a lower density when compared with the unreinforced matrix material. The distribution of particles, their size and shape, and volume fraction together with method production determinates the structure and properties of composite. Many other applications of composite products, such as sleeves, rings, cylinder blocks and pistons, need only a local displacement of reinforcement. Centrifugal casting MMC’s [2] is one of the methods, which can give a local: gradient or layered (Figs 1-3) particles concentration on the thickness of a mould [3-11]. In this method the structure depended on many factors, such as: rotational speed centrifugal form (Fig. 4), difference in density between the molten metal and ceramic particles, their volume fraction and reinforcement granulation (Fig. 6) as well as viscosity and crystallization conditions [12]. In this work stated that combinations of all these parameters make it possible to form the different of composites structure with any reinforcement distribution: uniform and heterogeneous with inside and outside (Fig. 8a) riched layers. Layer reinforcement of cast compositions, which is the subject of this article, allows to received good joint of special useful properties of reinforced areas - high hardness (Fig. 10) and wear resistance - with expected good mechanical properties of regions, which do not posses ceramic particles. That kind of materials will found application especially in tribological connections. Key words: composites Al-ceramic particles, centrifugal casting, structure