Conference Papers

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Author: search.filters.author.Mukunda, P.G.Has files: No

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    Effect of L/D ratio on Al-Si functionally graded material cast through centrifuge technique
    (2011) Kiran Aithal, A.S.; Narendranath; Desai, V.; Mukunda, P.G.
    Functionally Graded Material (FGM) is a class of material wherein the properties and structure are varied intentionally from one side to the other side of the specimen. This paper describes the effect of L/D (Length to Diameter) ratio of the cast on cast Al-Si FGM. The present study uses Al-17%wt Si to cast FGM's. The cast is evaluated for Microstructure and Hardness all along the length of the specimen. Three L/D ratios: 0.5, 1.0, 1.5 were cast using the Centrifuge Technique. The microstructures showed that enrichment of primary Si was largest in 1.5 ratio compared to other two. Hardness value of the cast at the upper and lower region were examined and found that gradient of hardness was more in 1.5 case. High volume percentage of primary Si was nearly 26% in the upper region and a hypoeutectic structure in the lower region. © (2011) Trans Tech Publications.
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    Inference of optimal speed for sound centrifugal casting of Al-12Si alloys
    (2011) Rao, S.; Mukunda, P.G.; Rao, S.S.; Sudhakar, K.G.
    True centrifugal casting is a standard casting technique for the manufacture of hollow, intricate and sound castings without the use of cores. The molten metal or alloy poured into the rotating mold forms a hollow casting as the centrifugal forces lift the liquid along the mold inner surface. When a mold is rotated at low and very high speeds defects are found in the final castings. Obtaining the critical speed for sound castings should not be a matter of guess or based on experience. The defects in the casting are mainly due to the behavior of the molten metal during the teeming and solidification process. Motion of molten metal at various speeds and its effect during casting are addressed in this paper. Eutectic Al-12Si alloy is taken as an experiment fluid and its performance during various rotational speeds is discussed.
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    Effect of process parameters on centrifugally cast Al-Si FGM
    (Minerals, Metals and Materials Society 184 Thorn Hill Road Warrendale PA 15086, 2013) Kiran Aithal, K.; Desai, V.; Narendranath, S.; Mukunda, P.G.
    Functionally Graded Materials (FGM) are such kind of materials wherein the properties and structure are varied from one end of the cast to the other intentionally. Centrifuge technique has been used in this study to produce Al-Si FGMs. Several process parameters determine the microstructure and the distribution of phases in the FG casting. These parameters include the size and initial concentration of alloying element, the centrifugal force, solidification rate, cooling rate. In this work an attempt has been made to produce FGMs using three different process variables such as mold temperature, melt temperature and mold rotational speed, their effect on the structure and properties. For this study Al-17wt%Si is used. From the results it is seen that for a particular melt and mold temperatures by increasing the mold rotation speed enhances the segregation of the Si particles at the one end of the casting. Similarly increasing mold or melt temperature only, increases the segregation.
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    Effect of centrifugal and gravity casting technique over metallographic and mechanical properties of spheroidal graphite iron
    (2013) Desai Gowda, H.S.; Mukunda, P.G.; Herbert, M.A.
    The mechanical properties of cast iron depend on the graphite morphology and characteristics of metallic matrix. In spheroidal graphite iron these properties are affected by the nodule count, nodule percentage, nodularity, nodules per square mm, nodule types and size distribution. In this work an attempt is made to study of the effect of centrifugal and gravity casting process on the morphology and mechanical properties. A comparison of microstructure and mechanical properties of specimens of the cast are studied. It has been observed that the centrifugal effect produces an increase in rupture strain but hardness is unaffected. In microstructure it has been observed that the centrifugal effect produces an increase in the number of bigger nodules and decrease in the number of smaller nodules and an increase of nodules per square mm. It has no effect on nodularity percentage. The centrifugal casting process produces better mechanical properties.
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    Effect of process parameters on centrifugally cast Al-Si FGM
    (Springer International Publishing, 2016) Kiran Aithal, A.S.; Desai, V.; Narendranath, S.; Mukunda, P.G.
    Functionally Graded Materials (FGM) are such kind of materials wherein the properties and structure are varied from one end of the cast to the other intentionally. Centrifuge technique has been used in this study to produce Al-Si FGMs. Several process parameters determine the microstructure and the distribution of phases in the FG casting. These parameters include the size and initial concentration of alloying element, the centrifugal force, solidification rate, cooling rate. In this work an attempt has been made to produce FGMs using three different process variables such as mold temperature, melt temperature and mold rotational speed, their effect on the structure and properties. For this study Al-17wt%Si is used. From the results it is seen that for a particular melt and mold temperatures by increasing the mold rotation speed enhances the segregation of the Si particles at the one end of the casting. Similarly increasing mold or melt temperature only, increases the segregation. © The Minerals, Metals & Materials Society 2016.
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    Effect of low temperature annealing on the wear properties of NITINOL
    (Institute of Physics Publishing michael.roberts@iop.org, 2016) Mukunda, S.; Naths, N.; Herbert, M.; Mukunda, P.G.
    NiTi shape memory alloy is a wonder material that is a solution looking for problems. The material finds wide biomedical applications like endodontic files for root canal treatment and cardiovascular stents. This material has rendered the surgical procedure simple compared to that with the existing Stainless Steel (SS) or titanium ones. NiTi as an endodontic file would cause less discomfort to the patients in comparison to that with far stiffer SS or titanium ones. Here nearly equi-atomic 50:50 commercial NiTi rods were subjected to low temperature aging at 300 to 450°C. The wear resistance of the as-received and the heat-treated samples was studied using adhesive wear tests on hardened steel counter face. Abrasive wear tests were run against Alumina disc to simulate the working of endodontic drills and files against dental hard and soft tissues. The abrasive wear resistance is expected to be proportional to the Vickers Hardness of the material and is high for the 450°C heat-treated sample. A correlation between the mechanical properties and microstructures of this material is attempted. © Published under licence by IOP Publishing Ltd.