Browsing by Author "Rajan, T.P.D."

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    Centrifugal casting and characterisation of primary silicon and Mg2Si dispersed aluminium functionally graded materials
    (2015) Midhun, Krishnan, P.; Hari, S.; Jayakumar, E.; Rajan, T.P.D.; Narayan, Prabhu, K.
    Aluminium based FGM rings, reinforced by in-situ primary Si and primary Si/ Mg2Si hybrid reinforcement were successfully fabricated by centrifugal casting and micro structural, chemical, hardness and corrosion characteristics were evaluated. It was observed that in Al-20Si ring the primary Si particles were present mostly in inner region and few in outer region where as in Al-20Si-3Mg ring both the primary silicon and Mg2Si were completely found in the inner region only resulting in a graded FGM structure. The hardness values were measured along radial direction of samples and variations corresponding to micro structural variation were analysed. Optical Emission spectroscopic studies have revealed the remarkable compositional changes along radial direction. Corrosion characteristics were also evaluated both in particle rich and depleted regions. � (2015) Trans Tech Publications, Switzerland.
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    Centrifugal casting and characterisation of primary silicon and Mg2Si dispersed aluminium functionally graded materials
    (Trans Tech Publications Ltd ttp@transtec.ch, 2015) Midhun Krishnan, P.; Sanil, S.; Jayakumar, E.; Rajan, T.P.D.; Prabhu, K.
    Aluminium based FGM rings, reinforced by in-situ primary Si and primary Si/ Mg2Si hybrid reinforcement were successfully fabricated by centrifugal casting and micro structural, chemical, hardness and corrosion characteristics were evaluated. It was observed that in Al-20Si ring the primary Si particles were present mostly in inner region and few in outer region where as in Al-20Si-3Mg ring both the primary silicon and Mg2Si were completely found in the inner region only resulting in a graded FGM structure. The hardness values were measured along radial direction of samples and variations corresponding to micro structural variation were analysed. Optical Emission spectroscopic studies have revealed the remarkable compositional changes along radial direction. Corrosion characteristics were also evaluated both in particle rich and depleted regions. © (2015) Trans Tech Publications, Switzerland.
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    Equal channel angular pressing of aluminum-alumina insitu metal matrix composite
    (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 ?m to 11 ?m is obtained in annealed and ECAP 2 pass condition. � (2012) Trans Tech Publications.
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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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    Processing of primary silicon and mg 2si reinforced hybrid functionally graded aluminum composites by centrifugal casting
    (2012) Raghunandan, S.; Akber, Hyder, J.; Rajan, T.P.D.; Narayan, Prabhu, K.; Pai, B.C.
    In the present investigation, FGMs of mono-dispersed in-situ primary Si and their hybrids with mg 2si reinforcements have been fabricated by the centrifugal casting process using 390 commercial Al alloy. Hard primary silicon particles are formed during the solidification of the 390 alloy and mg 2si reinforcements are formed by the addition of varying amount of magnesium into the A390 aluminium alloy. Owing to the difference in density both primary silicon and mg 2si gets segregated towards the inner periphery during centrifugal casting. The size of the mg 2si in-situ reinforcement phase is relatively smaller and is distributed in the edges of primary silicon particles and also individually in the matrix. The in-situ mg 2si and primary silicon can significantly increase the hardness and strength of the inner periphery of the casting. Higher Mg contents have been observed to introduce significant porosity leading to poor castings. Addition of phosphorous to the melt has led to the modification and refinement of primary Si morphology and also helped in the reduction of shrinkage porosity. Maximum hardness of 167 BHN is observed towards the inner periphery of the 390Al-2.5%Mg added in-situ composite. � (2012) Trans Tech Publications.
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    Processing of primary silicon and mg2si reinforced hybrid functionally graded aluminum composites by centrifugal casting
    (Trans Tech Publications Ltd ttp@transtec.ch, 2012) Raghunandan, S.; Akber Hyder, J.; Rajan, T.P.D.; Prabhu, K.N.; Pai, B.C.
    In the present investigation, FGMs of mono-dispersed in-situ primary Si and their hybrids with mg2si reinforcements have been fabricated by the centrifugal casting process using 390 commercial Al alloy. Hard primary silicon particles are formed during the solidification of the 390 alloy and mg 2si reinforcements are formed by the addition of varying amount of magnesium into the A390 aluminium alloy. Owing to the difference in density both primary silicon and mg2si gets segregated towards the inner periphery during centrifugal casting. The size of the mg2si in-situ reinforcement phase is relatively smaller and is distributed in the edges of primary silicon particles and also individually in the matrix. The in-situ mg2si and primary silicon can significantly increase the hardness and strength of the inner periphery of the casting. Higher Mg contents have been observed to introduce significant porosity leading to poor castings. Addition of phosphorous to the melt has led to the modification and refinement of primary Si morphology and also helped in the reduction of shrinkage porosity. Maximum hardness of 167 BHN is observed towards the inner periphery of the 390Al-2.5%Mg added in-situ composite. © (2012) Trans Tech Publications.