Proceedings of SerbiaTrib '13

Serbian TribologySocietySERBIATRIB ‘1313 th International Conference onTribologyKragujevac, Serbia, 15 – 17 May 2013Faculty of Engineeringin KragujevacWEAR PROPERTIES OF A356/10SiC/1Gr HYBRID COMPOSITESIN LUBRICATED SLIDING CONDITIONSBabić Miroslav 1 , Stojanović Blaža 1 , Mitrović Slobodan 1 , Bobić Ilija 2 , Miloradović Nenad 1 , Pantić Marko 1 ,Džunić Dragan 11 Faculty of Engineering, University of Kragujevac, Kragujevac, Serbia, babic@kg.ac.rs, blaza@kg.ac.rs2 Institution Institute of Nuclear Sciences “Vinca”, University of Belgrade, Belgrade, SerbiaAbstract: This paper presents basic tribological properties of A356/10SiC/1Gr hybrid composites inconditions with lubrication. Hybrid composite specimen is obtained by compocasting procedure. A356aluminium alloy is used as a base matrix alloy, reinforced with 10wt% of SiC and 1wt% of graphite.Tribological tests are done on advanced and computer supported tribometer with block-on-disc contact pair.By the experimental plan, test is conducted under three different values of sliding speed, three differentvalues of normal load, different sliding distances, and also different lubricants. SEM and EDS are used forwear analysis. The analysis has shown the presence of MML, which means that there was transfer ofmaterial from steel disc to composite block.Keywords: Hybrid composites, aluminium, SiC, graphite, wear, lubrication, MML.1. INTRODUCTIONAluminium is the most attractive material inautomotive, airplane, space and precise devicesindustry. Improvement of mechanical andtribological properties of aluminium can beachieved through aluminium reinforcement with theproper material and through creating compositematerial. The most effective improvement of theseproperties is achieved through creating hybridcomposites with two or more types ofreinforcements. By adding the ceramicreinforcement, mechanical properties of the matrixare changed, but in that case problem ofmachinability occurs. To improve machinability,the graphite is added to composite materials that arealready reinforced with ceramic material. Presenceof graphite reduces mechanical properties (hardnessdecreases), but tribological properties are improved[1-5].Basavarajappa et al [6-8] have studied thetribological behaviour of hybrid composites withaluminum base Al2219 reinforced by SiC andgraphite. They studied the tribological properties ofhybrid composites with 5, 10 and 15% SiC and 3%Gr obtained with process of liquid metallurgy. Thetribological tests show that wear decreases withincreasing SiC content in the hybrid composite.With increasing sliding speed and normal load,wear rate of composites is growing. Mahdavi andAkhlaghi [9,10] have studied the tribologicalproperties of Al / SiC / Gr hybrid compositesobtained by In situ Powder Metallurgy process.Aluminum alloy Al 6061 is used as a base,reinforced with graphite 9% and 0 ÷ 40% SiC. Thetribological tests are done on tribometer with pin ondisc contact, and the composite with 20% SiC hasthe best properties. Further increase of SiC leads toincreased wear of hybrid composites.Suresh and Sridhara [11-14] have studied theeffect of SiC content and graphite on thetribological behaviour of hybrid Al / SiC / Grcomposites with aluminum base LM25 (Al-Si7Mg0.5) obtained by stircasting process.Ames and Alpas have [15] studied thetribological testing of hybrid composites with a baseof aluminum alloy A356 reinforced with 20% SiCand 3 ÷ 10% Gr. The tribological tests are done ontribometer with block on ring contact. The wear rateof hybrid composites is significantly lower than thewear rate of the base material withoutreinforcements, especially at low normal loads.Vencl et al [16,17] have studied the tribologicalbehaviour of hybrid composites with the A35613 th International Conference on Tribology – Serbiatrib’13 129