Conference Papers

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    Equal channel angular pressing of aluminum-alumina insitu metal matrix composite
    (Trans Tech Publications Ltd ttp@transtec.ch, 2012) Athreya, C.N.; Mahesh, V.P.; Brahmakumar, M.; Rajan, T.P.D.; Prabhu, K.N.; Pai, B.C.; Gupta, R.K.; Ramkumar, P.
    The present investigation is on synthesis of in situ Al-alumina composite and to evaluate the effect of equal channel angular pressing on the refinement of the grain structure and enhancement in the hardness and the strength. The billets pressed in as cast condition has shown cracks during first pass. The billets pressed immediately after solution treatment for one pass and followed by ageing treatment immediately after pressing exhibited very high hardness of 125BHN against 95 BHN to that of the T6 condition of 6061 aluminium alloy. The microstructural refinement from 35 μm to 11 μm is obtained in annealed and ECAP 2 pass condition. © (2012) Trans Tech Publications.
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    Plasma-sprayed graphene oxide reinforced alumina composite coatings on low carbon steel with improved fracture toughness, brittleness index, and microhardness
    (Elsevier Ltd, 2020) Amudha, A.; Nagaraja, H.S.; Shashikala, H.D.
    In this work, the mechanical properties of atmospheric plasma-sprayed Al2O3and Al2O3-xGO (x = 0.5, 1.0, 1.5, and 2.0 wt%) coatings on low carbon steel was evaluated using the Vickers indentation technique, and the effects of GO addition in microhardness brittleness index and fracture toughness were investigated. The Fourier-transform infrared (FTIR) spectroscopy and Field Emission Scanning Electron Microscopy (FE-SEM) techniques were employed to analyze the microstructural characterization of the plasma-sprayed coatings and to confirm the retention of GO in the Al2O3-xGO composite after the plasma spray. It was found that the Vicker's microhardness of as-sprayed Al2O3is 4.148 GPa and it decreased with the increase in the addition of GO and for Al2O3-2.0GO, it is 3.305 GPa. The fracture toughness of Al2O3is 4.86 (MPa m1/2) whereas for Al2O3-2.0GO is 16.85 (MPa m1/2). The fracture toughness has increased whereas the brittleness index has decreased as the weight percentage of GO addition is increased in the Al2O3-GO composite. Thus, the plasma-sprayed Al2O3and Al2O3-xGO coatings suggest that 2 wt% GO addition helps in the improvement of brittleness, fracture toughness, and the microhardness. © 2020 Elsevier Ltd. All rights reserved.