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S. A. Kori - One of the best experts on this subject based on the ideXlab platform.
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Effect of a Grain Refiner cum modifier on mechanical properties of Al-7Si and Al-11Si alloys
Metals and Materials International, 2013Co-Authors: S. M. Jigajinni, K. Venkateswarlu, S. A. KoriAbstract:This study evaluates the influence of Grain Refiners/modifiers on the mechanical properties of the Al-7Si and Al-11Si alloys with an experiment of quantitative and qualitative correlations with the microstructure. Modification of Al-Si alloys with strontium additions and Grain refinement with Al-Ti, Al-B and Al-T-B master alloy additions are demonstrated to be efficient on Al-Si alloys. A single master alloy with combined additions of Sr and Ti and/or B was prepared and the microstructure and mechanical properties were studied. The results show that boron rich (Al-3B-Sr and Al-1Ti-3B-Sr) master alloys are more efficient than Ti rich (Al-3Ti-Sr and Al-5Ti-1B-Sr) master alloys considering their combined Grain refinement and modification effect on Al-7Si and Al-11Si alloys. However, the presence of Sr does not influence the Grain refinement. Similarly, presence of Grain Refiner does not influence the modification of eutectic Si.
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computer aided cooling curve analysis for al 5si and al 11si alloys
International journal of engineering science and technology, 2012Co-Authors: S. M. Jigajinni, K. Venkateswarlu, S. A. KoriAbstract:The effect of Grain Refiner, modifier, and combination of Grain Refiner cum modifier was studied on Al-5Si and Al-11Si alloys using computer aided cooling curve analysis. For combined Grain refinement and modification effect, Al-Ti-B-Sr single master alloy was developed that acted as both Grain Refiner and modifier. For thermal analysis, the temperature throughout the solidification range was recorded. The resultant plot of temperature versus time was thermal analysis. The computer aided cooling curve analysis studies shows that the extent of undercooling ΔT α-Al was reduced significantly after the addition of Grain Refiner to the melt. It also indicates that the eutectic temperature was suppressed on the addition of modifier to the melt.
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effect of Grain refinement and modification on the dry sliding wear behaviour of eutectic al si alloys
Tribology International, 2009Co-Authors: T M Chandrashekharaiah, S. A. KoriAbstract:Abstract The present study deals with an investigation of dry sliding wear behaviour of Grain refined and or modified eutectic (Al–12Si) Al–Si alloy by using a Pin-On-Disc machine. The indigenously developed Al–1Ti–3B and Al–10Sr master alloys were used as Grain Refiner and modifier for the Grain refinement of α -Al dendrites and modification of eutectic Si, respectively. Various parameters have been studied such as alloy composition, sliding speed, sliding distance and normal pressure. The cast alloys, master alloys and worn surfaces were characterized by SEM/EDX microanalysis. Results suggest that, the wear resistance of eutectic Al–Si alloys increases with the addition of Grain Refiner (Al–1Ti–3B) and or modifier (Al–10Sr). Further, the worn surface studies show that adhesive wear was observed in Al–12Si alloy in the absence of Grain Refiner and modifier. However, an abrasive and oxidative wear was observed when the Grain Refiner and modifier are added to the same alloy. Commercially available LM-6 (12.5%Si) alloy was used for comparison.
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studies on the dry sliding wear behaviour of hypoeutectic and eutectic al si alloys
Wear, 2007Co-Authors: S. A. Kori, T M ChandrashekharaiahAbstract:Abstract The effect of Grain Refiner and or modifier on the wear behaviour of hypoeutectic (Al–0.2, 2, 3, 4, 5 and 7Si) and eutectic (Al–12Si) alloys has been investigated using a Pin-On-Disc machine. Various parameters such as alloy composition, normal pressure, sliding speed and sliding distance were studied on the hypoeutectic and eutectic Al–Si alloys. The cast master alloys (Al–5Ti–1B, Al–1Ti–3B and Al–10Sr) and worn surfaces were then characterized by SEM/EDX microanalysis. The results suggest that the wear resistance of hypoeutectic and eutectic Al–Si alloys increase with the addition of Grain Refiner and or modifier as compared to the absence of Grain Refiner and or modifier. The present results also reveal an improvement in the mechanical and tribological properties, obtained due to the change in microstructure from coarse columnar dendrites to fine equiaxed dendrites and plate like eutectic Si to fine particles due to the addition of Al–Ti–B Grain Refiner and modifier (Sr), respectively.
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Grain refinement of aluminium and its alloys by heterogeneous nucleation and alloying
International Materials Reviews, 2002Co-Authors: B.s. Murty, S. A. Kori, M. ChakrabortyAbstract:Grain refinement of aluminium and its alloys is common industrial practice. The field has been extensively investigated by many workers over the past 50 years, not only to develop efficient Grain Refiners for different aluminium alloys, but also to achieve an understanding of the mechanism of Grain refinement. The present review confines itself to the literature on Grain refinement by heterogeneous nucleation and alloying. Initially, the fundamentals of Grain refinement by inoculants are outlined. The types of Grain Refiner, Al-Ti-B master alloys in particular, and their methods of manufacture are next discussed. The Grain refining tests to assess the efficiency of the Grain Refiners and the Grain refining behaviour of aluminium alloys are also discussed in brief. The performance of a Grain Refiner, as well as the response of an aluminium alloy to Grain refinement, is influenced by the microstructure of the Grain Refiner as controlled by the process parameters involved in its preparation and the alloying elements present in the aluminium alloy. The roles of these factors, and particularly the roles of poisoning elements such as Si, Cr, Zr, Li, are reviewed. The paper also reviews the mechanisms of Grain refinement, the fading and poisoning phenomena, and the trends in the development of new Grain Refiners for aluminium alloys containing poisoning elements.
M. Chakraborty - One of the best experts on this subject based on the ideXlab platform.
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Design of an Ideal Grain-Refiner Alloy for Al-7Si Alloy Using Artificial Neural Networks
Journal of Materials Engineering and Performance, 2013Co-Authors: N. S. Reddy, M. Chakraborty, A. K. Prasada Rao, J. Krishnaiah, B.s. MurtyAbstract:An ideal Grain Refiner has been designed for Al-7Si alloy by performing sensitivity analysis of trained artificial neural network (ANN) model. An ANNs model has been developed for solving these complex Grain refinement phenomena in Al-7Si alloy. The model predictions and the analysis are well in agreement with the experimental results and existing metallurgical facts. Uncertainty in predictions helped in finding a new phenomenon at lower addition levels of Grain Refiner.
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microstructural features of as cast a356 alloy inoculated with sr sb modifiers and al ti c Grain Refiner simultaneously
Materials Letters, 2008Co-Authors: A Prasada K Rao, B.s. Murty, Karabi Das, M. ChakrabortyAbstract:This article focuses on the microstructural refinement of as-cast A356 alloy, obtained by melt inoculation of the same. The inoculants used are Sr (modifier), Sb (modifier) and Al-Ti-C (Grain Refiner). Microstructural characterization of A356 alloy reveals that the Secondary Dendritic Arm Spacing (SDAS) of α-Al dendrites and size/morphology of eutectic silicon decrease by treating the melt with pre-defined amounts of Sr, Sb and Al-5Ti-2C Grain Refiner. Microstructure of the inoculated as-cast A356 alloy shows that, modified eutectic-silicon exhibits fine fibrous morphology at shorter melt holding, while the same exhibits fine lamellar morphology on longer melt holding.
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the effect of isothermal mechanical stirring on an al si alloy in the semisolid condition
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2004Co-Authors: K Sukumaran, B C Pai, M. ChakrabortyAbstract:Abstract Isothermal rheocasting studies were carried out on Al–5.2Si alloy under different processing conditions. The parameters varied are the shear rate, time of stirring, addition of Grain Refiner and the cooling rate. The addition of Grain Refiner prior to stirring has been found to influence the size and morphology of the primary particles. The shear rate–time combination has found to have tremendous effect in deciding the primary particle morphology. By proper selection of the processing parameters, globular primary particles can be obtained by mechanical stirring with a radial flow impeller in the semisolid range. The observed particle growth with increasing isothermal shearing time could be understood with the available theories of particle growth.
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Grain refinement of aluminium and its alloys by heterogeneous nucleation and alloying
International Materials Reviews, 2002Co-Authors: B.s. Murty, S. A. Kori, M. ChakrabortyAbstract:Grain refinement of aluminium and its alloys is common industrial practice. The field has been extensively investigated by many workers over the past 50 years, not only to develop efficient Grain Refiners for different aluminium alloys, but also to achieve an understanding of the mechanism of Grain refinement. The present review confines itself to the literature on Grain refinement by heterogeneous nucleation and alloying. Initially, the fundamentals of Grain refinement by inoculants are outlined. The types of Grain Refiner, Al-Ti-B master alloys in particular, and their methods of manufacture are next discussed. The Grain refining tests to assess the efficiency of the Grain Refiners and the Grain refining behaviour of aluminium alloys are also discussed in brief. The performance of a Grain Refiner, as well as the response of an aluminium alloy to Grain refinement, is influenced by the microstructure of the Grain Refiner as controlled by the process parameters involved in its preparation and the alloying elements present in the aluminium alloy. The roles of these factors, and particularly the roles of poisoning elements such as Si, Cr, Zr, Li, are reviewed. The paper also reviews the mechanisms of Grain refinement, the fading and poisoning phenomena, and the trends in the development of new Grain Refiners for aluminium alloys containing poisoning elements.
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development of an efficient Grain Refiner for al 7si alloy
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2000Co-Authors: S. A. Kori, B.s. Murty, M. ChakrabortyAbstract:Abstract The response of Al–7Si alloy towards Grain refinement by Al–Ti–B master alloys (with different Ti–B ratios) at different addition levels has been studied in detail. The results indicate that high B-containing master alloys are powerful Grain Refiners when compared to conventional Grain Refiners like Al–5Ti–lB master alloys. In the present study, indigenously developed master alloys have been used for the Grain refinement of alloys Al–7Si and LM-25 . Significant improvements in mechanical properties have been obtained with a combination of Grain Refiner and Sr as modifier.
M Emamy - One of the best experts on this subject based on the ideXlab platform.
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investigation of the effect of al 5ti 1b Grain Refiner on dry sliding wear behavior of an al zn mg cu alloy formed by strain induced melt activation process
Materials & Design, 2013Co-Authors: Mohammad Alipour, Baharak Ghorbanian Aghdam, Hamid Ebrahimi Rahnoma, M EmamyAbstract:Abstract This study was undertaken to investigate the influence of Al–5Ti–1B master alloy and modified strain-induced melt activation process on the structural characteristics, mechanical properties and dry sliding wear behavior of Al–12Zn–3Mg–2.5Cu aluminum alloy. The optimum amount of Ti containing master alloy for proper Grain refining was selected as 2 wt.%. The alloy was produced by modified strain-induced melt activation (SIMA) process. Reheating condition to obtain a fine globular microstructure was optimized. The optimum temperature and time in strain-induced melt activation process are 575 °C and 20 min, respectively. T6 heat treatment was applied for all specimens before tensile testing. Significant improvements in mechanical properties were obtained with the addition of Grain Refiner combined with T6 heat treatment. After the T6 heat treatment, the average tensile strength increased from 283 MPa to 587 MPa and 252 MPa to 564 MPa for samples refined with 2 wt.% Al–5Ti–1B before and after strain-induced melt activation process, respectively. Dry sliding wear performance of the alloy was examined in normal atmospheric conditions. The experimental results showed that the T6 heat treatment considerably improved the resistance of Al–12Zn–3Mg–2.5Cu aluminum alloy to the dry sliding wear. The results showed that ultimate strength and dry sliding wear performance of globular microstructure specimens was a lower value than that of Ti-refined specimens without strain-induced melt activation process.
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the effect of al 5ti 1b Grain Refiner on the structure and tensile properties of al 20 mg alloy
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2013Co-Authors: O. Fakhraei, M Emamy, H FarhangiAbstract:Abstract In current research, the effect of Al–5Ti–1B Grain Refiner on the structure and tensile properties of Al–20%Mg alloy have been investigated. Scanning electron microscopy (SEM) and Energy Dispersive X-ray (EDX) analysis were utilized to study the microstructure and fracture surfaces of samples. Microstructural analysis of the cast alloy showed the dendrites of a primary α-phase solid solution within the eutectic matrix which consists of β-Al 3 Mg 2 intermetallic and α-solid solution. The results indicated that adding Al–5Ti–1B to the alloy caused a significant rise in the ultimate tensile strength (UTS) and elongation values from 168 MPa and 1.2% to maximum 253 MPa and 2.4%, respectively. The main mechanisms for the observed enhancement were found to be due to the refinement of Grains during solidification and also segregation of Ti to the tip of Al (α) dendrites. This phenomenon controls the dendritic growth and changes the morphology of this phase from interconnected coarse dendrites to a star-like morphology.
Mohammad Alipour - One of the best experts on this subject based on the ideXlab platform.
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investigation of the effect of al 5ti 1b Grain Refiner on dry sliding wear behavior of an al zn mg cu alloy formed by strain induced melt activation process
Materials & Design, 2013Co-Authors: Mohammad Alipour, Baharak Ghorbanian Aghdam, Hamid Ebrahimi Rahnoma, M EmamyAbstract:Abstract This study was undertaken to investigate the influence of Al–5Ti–1B master alloy and modified strain-induced melt activation process on the structural characteristics, mechanical properties and dry sliding wear behavior of Al–12Zn–3Mg–2.5Cu aluminum alloy. The optimum amount of Ti containing master alloy for proper Grain refining was selected as 2 wt.%. The alloy was produced by modified strain-induced melt activation (SIMA) process. Reheating condition to obtain a fine globular microstructure was optimized. The optimum temperature and time in strain-induced melt activation process are 575 °C and 20 min, respectively. T6 heat treatment was applied for all specimens before tensile testing. Significant improvements in mechanical properties were obtained with the addition of Grain Refiner combined with T6 heat treatment. After the T6 heat treatment, the average tensile strength increased from 283 MPa to 587 MPa and 252 MPa to 564 MPa for samples refined with 2 wt.% Al–5Ti–1B before and after strain-induced melt activation process, respectively. Dry sliding wear performance of the alloy was examined in normal atmospheric conditions. The experimental results showed that the T6 heat treatment considerably improved the resistance of Al–12Zn–3Mg–2.5Cu aluminum alloy to the dry sliding wear. The results showed that ultimate strength and dry sliding wear performance of globular microstructure specimens was a lower value than that of Ti-refined specimens without strain-induced melt activation process.
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The effect of Al–8B Grain Refiner and heat treatment conditions on the microstructure, mechanical properties and dry sliding wear behavior of an Al–12Zn–3Mg–2.5Cu aluminum alloy
Materials & Design, 2012Co-Authors: Mohammad Alipour, Mortaza Azarbarmas, F. Heydari, M. Hoghoughi, M. Alidoost, Masoud EmamyAbstract:Abstract In this study the effect of Al–8B Grain Refiner on the structural and properties of Al–12Zn–3Mg–2.5Cu aluminum alloy were investigated. The optimum amount for B containing Grain Refiner was selected as 3.75 wt.%. The results showed that B containing Grain Refiner is more effective in reducing average Grain size of the alloy. T6 heat treatment was applied for all specimens before tensile testing. Significant improvements in mechanical properties were obtained with the addition of Grain Refiner combined with T6 heat treatment. After the heat treatment, the average tensile strength increased from 479 MPa to 537 MPa for sample refined with 3.75 wt.% Al–8B. The fractography of the fractured faces and microstructure evolution was characterized by scanning electron microscopy and optical microscopy. Dry sliding wear performance of the alloy was examined in normal atmospheric conditions. The experimental results showed that the T6 heat treatment considerably improved the resistance of Al–12Zn–3Mg–2.5Cu aluminum alloy to the dry sliding wear.
Nedumbilly Prasanth - One of the best experts on this subject based on the ideXlab platform.
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effect of al 5ti 1b Grain Refiner on the microstructure mechanical properties and acoustic emission characteristics of al5052 aluminium alloy
Journal of materials research and technology, 2015Co-Authors: Amulya Bihari Pattnaik, S Das, B B Jha, Nedumbilly PrasanthAbstract:Abstract In the present investigation, the effect of Al–5Ti–1B Grain Refiner on the microstructure, mechanical properties and acoustic emission characteristics of Al 5052 aluminium alloy have been studied. Microstructural analysis showed the presence of primary α solid solution. No Al–Mg phase was found to be formed due to the presence of magnesium in the solid solution. The results indicated that the addition of Al–5Ti–1B Grain Refiner into the alloy caused a significant improvement in ultimate tensile strength (UTS) and elongation values from 114 MPa and 7.8% to 185 MPa and 18% respectively. The main mechanisms behind this improvement were found to be due to the Grain refinement during solidification and segregation of Ti at primary α Grain boundaries. Acoustic emission (AE) results indicated that intensity of AE signals increased with increase in Al–5Ti–1B master alloy content, which had been attributed to the combined effect of dislocation motion and Grain refinement. The field emission scanning electron microscopy (FESEM) and energy dispersive X-ray (EDX) analysis were used to study the microstructure and fracture surfaces of the samples.
