1. |
- Korojy, Bahman, et al.
(author)
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On solidification of hypereutectic Al-Si alloys
- 2009
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In: Transactions of the Indian Institute of Metals. - : Springer Science and Business Media LLC. - 0019-493X .- 0972-2815 .- 0975-1645. ; 62:4-5, s. 361-365
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Journal article (peer-reviewed)abstract
- Precipitation of primary silicon was studied in Al-Si hypereutectic alloys with 15, 18, and 25 wt. % silicon content. The alloys were solidified with different cooling rates from different super heat temperatures. The liquidus and eutectic temperature were evaluated from the cooling curves. The liquidus temperature was found to decrease with cooling rate. The evaluation of microstructure showed that the fraction of primary silicon decreased with increasing the cooling rate and super heat temperature. Furthermore, the morphology of the primary silicon changed as an effect of cooling rate and super heat temperature.
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2. |
- Ranganathan, Sathees, et al.
(author)
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Influence of melt temperature on Rapid solidification of Al-Y and Al-Si alloy system
- 2009
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In: Transactions of the Indian Institute of Metals. - : Springer Science and Business Media LLC. - 0019-493X .- 0972-2815 .- 0975-1645. ; 62:4-5, s. 515-519
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Journal article (peer-reviewed)abstract
- Solidification behavior of Al-Y and Al-Si were investigated for different melt temperatures. Levitation casting technique was used to achieve a cooling rate of around similar to 2000K/s during the experiment. Light optical microscopy (LOM) and Scanning electron microscopy (SEM) were used to analyze the samples. An energy dispersive system (EDS) analysis of SEM was performed on the samples to identify the phases. Plate like structure of Al8Y3 primary phase was observed at low melt temperature with small percentage of peritectic transformation of Al8Y3 and liquid melt into Al9Y2. A pre-dentritic star like crystal of Al3Y was observed in a fine eutectic matrix at very high melt temperature. Amount and number of primary Si crystals formed in a unit area during the solidification increases as the melt temperature increases. It is believed the melt temperature affects the solidification pattern by changing chemical short range order.
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3. |
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4. |
- Vijh, G., et al.
(author)
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Solid freeform fabrication of aluminum alloy components : Numerical simulations
- 2009
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In: Transactions of the Indian Institute of Metals. - : Springer Science and Business Media LLC. - 0019-493X .- 0972-2815 .- 0975-1645. ; 62:4-5, s. 291-294
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Journal article (peer-reviewed)abstract
- A heat transfer model has been developed to simulate the evolution of temperature during semi-solid metal (SSM) solid freeform fabrication (SFF) process. The governing equations were solved numerically using finite difference method. Deposition of simple cubic components of A356 (Al-7%Si-0.45%Mg) aluminum alloy have been simulated. The effect of process parameters such as deposition pattern, deposition velocity, slurry cross-section and slurry temperature on the transient temperature distribution in these components have been studied. Out of the three deposition patterns studied, i.e. rotating, alternating and unidirectional, the alternating pattern enabled depositing larger interfacefree components. Increasing the slurry flow rate resulted in the deposition of larger interface-free components
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5. |
- Åberg, J., et al.
(author)
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Heat-flux measurements of industrial on-site continuous copper casting and their use as boundary conditions for numerical simulations
- 2009
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In: Transactions of the Indian Institute of Metals. - : Springer Science and Business Media LLC. - 0019-493X .- 0972-2815 .- 0975-1645. ; 62:4-5, s. 443-446
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Journal article (peer-reviewed)abstract
- An embedded sensor, designed for rapid and accurate response times and using wireless data transmission, has been developed for the on-site measurement of temperatures in industrial continuous casting moulds. The sensor has been used to measure the temperature at several points in the mould during production in a Southwire copper casting process. The measured data has been used to calculate the temperature gradient in the mould to estimate the heat flux through it; this is then used as a boundary condition for numerical simulations of solidification. For these, we employ a method that tracks the solidification front explicitly; this has an advantage over fixed-grid methods in simulations for materials having a short solidification interval, since the release of latent heat at the solidification front can be resolved without resorting to a very fine mesh. The special considerations required for setting the initial condition for the numerical scheme and the time taken for the superheated melt to form a solid shell are also discussed.
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6. |
- Åberg, Lena Magnusson, et al.
(author)
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Heat of Solidification in Refractory Metals Studied by Drop-Tube Experiments
- 2009
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In: Transactions of the Indian Institute of Metals. - : Springer Science and Business Media LLC. - 0019-493X .- 0972-2815 .- 0975-1645. ; 62:4-5, s. 269-273
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Journal article (other academic/artistic)abstract
- A number of pure refractory metals have been investigated by drop-tube experiments. The cooling curves have been registered and theoretically analysed. A model for analysing the heat of fusion has been developed. It was found that the heat of fusion was approximately 50% of the tabulated value.
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7. |
- Åberg, Jonas, et al.
(author)
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An On-site Industrial Experimental Heat Flux Study during Solidification of Pure Copper in the Southwire Process
- 2007
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In: T INDIAN I METALS. - 0972-2815. ; 60:2-3, s. 191-196
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Journal article (peer-reviewed)abstract
- To study the production of pure copper and copper alloys in the Southwire process the temperature in the mould has been measured on-site in the production process in a number of positions. To increase the accuracy and robustness of measurements a new type of thermocouple based temperature sensor has been developed and tested. The test system includes wireless transmission of measured data from the moving mould. The results from the measurements are then used to calculate the energy transfer rate from the solidifying shell as a function of time. An initial in-situ measurement campaign has been performed and the results are very promising.
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