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Ericson Gordo - One of the best experts on this subject based on the ideXlab platform.
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flexural properties thermal conductivity and electrical resistivity of preAlloyed and Master Alloy addition powder metallurgy ti 6al 4v
Materials & Design, 2013Co-Authors: Leandro Bolzoni, E M Ruiznavas, Ericson GordoAbstract:Abstract A comparison between the properties achievable by processing the Ti–6Al–4V Alloys by means of two powder metallurgy approaches, precisely preAlloyed and Master Alloy addition, was carried out. PreAlloyed and Master Alloy addition hydride–dehydride powders characterised by an irregular morphology were shaped by means of cold uniaxial pressing and high vacuum sintered considering the effect of the variation of the sintering temperature and of the dwell time. Generally, the higher the temperature and the longer the dwell time, the higher the relative density and, consequently, the better the mechanical performances. Nevertheless, a higher processing temperature or a longer time leads also to some interstitials pick-up, especially oxygen, which affects the mechanical behaviour and, in particular, lowers the ductility. Although some residual porosity is left by the pressing and sintering route, mechanical properties, thermal conductivity and electrical resistivity values comparable to those of the wrought Alloy are obtained.
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Flexural properties, thermal conductivity and electrical resistivity of preAlloyed and Master Alloy addition powder metallurgy Ti-6Al-4V
Materials and Design, 2013Co-Authors: Leandro Bolzoni, E. M. Ruiz Navas, Ericson GordoAbstract:A comparison between the properties achievable by processing the Ti-6Al-4V Alloys by means of two powder metallurgy approaches, precisely preAlloyed and Master Alloy addition, was carried out. PreAlloyed and Master Alloy addition hydride-dehydride powders characterised by an irregular morphology were shaped by means of cold uniaxial pressing and high vacuum sintered considering the effect of the variation of the sintering temperature and of the dwell time. Generally, the higher the temperature and the longer the dwell time, the higher the relative density and, consequently, the better the mechanical performances. Nevertheless, a higher processing temperature or a longer time leads also to some interstitials pick-up, especially oxygen, which affects the mechanical behaviour and, in particular, lowers the ductility. Although some residual porosity is left by the pressing and sintering route, mechanical properties, thermal conductivity and electrical resistivity values comparable to those of the wrought Alloy are obtained. © 2013 Elsevier Ltd.
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mechanical behaviour of pressed and sintered titanium Alloys obtained from Master Alloy addition powders
Journal of The Mechanical Behavior of Biomedical Materials, 2012Co-Authors: Leandro Bolzoni, P G Esteban, E M Ruiznavas, Ericson GordoAbstract:Abstract The fabrication of the workhorse Ti–6Al–4V Alloy and of the Ti–3Al–2.5V Alloy was studied considering the Master Alloy addition variant of the blending elemental approach conventionally used for titanium powder metallurgy. The powders were characterised by means thermal analysis and X-ray diffraction and shaped by means of uniaxial pressing. The microstructural evolution with the sintering temperature (900–1400 °C) was evaluated by SEM and EDS was used to study the composition. XRD patterns as well as the density by Archimedes method were also obtained. The results indicate that Master Alloy addition is a suitable way to fabricate well developed titanium Alloy but also to produce Alloy with the desired composition, not available commercially. Density of 4.3 g/cm 3 can be obtained where a temperature higher than 1200 °C is needed for the complete diffusion of the Alloying elements. Flexural properties comparable to those specified for wrought Ti–6Al–4V medical devices are, generally, obtained.
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influence of powder characteristics on sintering behaviour and properties of pm ti Alloys produced from preAlloyed powder and Master Alloy
Powder Metallurgy, 2011Co-Authors: Leandro Bolzoni, P G Esteban, E M Ruiznavas, Ericson GordoAbstract:The use and development of titanium and titanium Alloys have been strongly correlated to high technology industries where costs are not the most important aspect. Titanium could see its market grow by the application of lower cost and more efficient processing methods such as powder metallurgy. This work deals with the characterisation of two types of powders: commercial preAlloyed powder and powder produced from Master Alloy combining mechanical milling and conventional blending to adjust the particle size. The characteristics of the powders, sintering behaviour and final properties of the parts indicate that the Master Alloy approach leads to better compressibility than the preAlloyed powders and, therefore, to lower dimensional change during sintering. The most important result is that it is possible to obtain Ti Alloys with properties similar to or better than Alloys from preAlloyed powders and to obtain homogeneous microstructures, which allows the composition to be adjusted to requirements.
Leandro Bolzoni - One of the best experts on this subject based on the ideXlab platform.
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flexural properties thermal conductivity and electrical resistivity of preAlloyed and Master Alloy addition powder metallurgy ti 6al 4v
Materials & Design, 2013Co-Authors: Leandro Bolzoni, E M Ruiznavas, Ericson GordoAbstract:Abstract A comparison between the properties achievable by processing the Ti–6Al–4V Alloys by means of two powder metallurgy approaches, precisely preAlloyed and Master Alloy addition, was carried out. PreAlloyed and Master Alloy addition hydride–dehydride powders characterised by an irregular morphology were shaped by means of cold uniaxial pressing and high vacuum sintered considering the effect of the variation of the sintering temperature and of the dwell time. Generally, the higher the temperature and the longer the dwell time, the higher the relative density and, consequently, the better the mechanical performances. Nevertheless, a higher processing temperature or a longer time leads also to some interstitials pick-up, especially oxygen, which affects the mechanical behaviour and, in particular, lowers the ductility. Although some residual porosity is left by the pressing and sintering route, mechanical properties, thermal conductivity and electrical resistivity values comparable to those of the wrought Alloy are obtained.
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Flexural properties, thermal conductivity and electrical resistivity of preAlloyed and Master Alloy addition powder metallurgy Ti-6Al-4V
Materials and Design, 2013Co-Authors: Leandro Bolzoni, E. M. Ruiz Navas, Ericson GordoAbstract:A comparison between the properties achievable by processing the Ti-6Al-4V Alloys by means of two powder metallurgy approaches, precisely preAlloyed and Master Alloy addition, was carried out. PreAlloyed and Master Alloy addition hydride-dehydride powders characterised by an irregular morphology were shaped by means of cold uniaxial pressing and high vacuum sintered considering the effect of the variation of the sintering temperature and of the dwell time. Generally, the higher the temperature and the longer the dwell time, the higher the relative density and, consequently, the better the mechanical performances. Nevertheless, a higher processing temperature or a longer time leads also to some interstitials pick-up, especially oxygen, which affects the mechanical behaviour and, in particular, lowers the ductility. Although some residual porosity is left by the pressing and sintering route, mechanical properties, thermal conductivity and electrical resistivity values comparable to those of the wrought Alloy are obtained. © 2013 Elsevier Ltd.
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mechanical behaviour of pressed and sintered titanium Alloys obtained from Master Alloy addition powders
Journal of The Mechanical Behavior of Biomedical Materials, 2012Co-Authors: Leandro Bolzoni, P G Esteban, E M Ruiznavas, Ericson GordoAbstract:Abstract The fabrication of the workhorse Ti–6Al–4V Alloy and of the Ti–3Al–2.5V Alloy was studied considering the Master Alloy addition variant of the blending elemental approach conventionally used for titanium powder metallurgy. The powders were characterised by means thermal analysis and X-ray diffraction and shaped by means of uniaxial pressing. The microstructural evolution with the sintering temperature (900–1400 °C) was evaluated by SEM and EDS was used to study the composition. XRD patterns as well as the density by Archimedes method were also obtained. The results indicate that Master Alloy addition is a suitable way to fabricate well developed titanium Alloy but also to produce Alloy with the desired composition, not available commercially. Density of 4.3 g/cm 3 can be obtained where a temperature higher than 1200 °C is needed for the complete diffusion of the Alloying elements. Flexural properties comparable to those specified for wrought Ti–6Al–4V medical devices are, generally, obtained.
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influence of powder characteristics on sintering behaviour and properties of pm ti Alloys produced from preAlloyed powder and Master Alloy
Powder Metallurgy, 2011Co-Authors: Leandro Bolzoni, P G Esteban, E M Ruiznavas, Ericson GordoAbstract:The use and development of titanium and titanium Alloys have been strongly correlated to high technology industries where costs are not the most important aspect. Titanium could see its market grow by the application of lower cost and more efficient processing methods such as powder metallurgy. This work deals with the characterisation of two types of powders: commercial preAlloyed powder and powder produced from Master Alloy combining mechanical milling and conventional blending to adjust the particle size. The characteristics of the powders, sintering behaviour and final properties of the parts indicate that the Master Alloy approach leads to better compressibility than the preAlloyed powders and, therefore, to lower dimensional change during sintering. The most important result is that it is possible to obtain Ti Alloys with properties similar to or better than Alloys from preAlloyed powders and to obtain homogeneous microstructures, which allows the composition to be adjusted to requirements.
M Chakraborty - One of the best experts on this subject based on the ideXlab platform.
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al ti c sr Master Alloy a melt inoculant for simultaneous grain refinement and modification of hypoeutectic al si Alloys
Journal of Alloys and Compounds, 2009Co-Authors: B S Murty, M ChakrabortyAbstract:Abstract Present article is focused on the microstructural features of Al–Ti–C–Sr Master Alloy, an inoculant for simultaneous grain refinement and modification of hypoeutectic Al–Si Alloys. This Master Alloy is basically a metal matrix composite consisting of TiC and Al 4 Sr phases formed in situ in the Al-matrix. TiC particles initiate the refinement of primary α-Al through heterogeneous nucleation in molten hypoeutectic Al–Si Alloy, while Al 4 Sr phase dissolves in molten Al–7Si Alloy enriching the melt with Sr, which eventually leads to modification of eutectic silicon during solidification of the Al–7Si Alloy casting. Thus present Master Alloy serves in both ways, as a grain refiner and a modifier for hypoeutectic Al–Si Alloys.
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microstructural and wear behavior of hypoeutectic al si Alloy lm25 grain refined and modified with al ti c sr Master Alloy
Wear, 2006Co-Authors: B S Murty, M ChakrabortyAbstract:Abstract Present article reports the microstructure and wear behavior of grain refined and modified Al–7Si–0.3Mg (LM25) Alloy. Combined grain refinement and modification is achieved by inoculating LM25 melt with various inoculation levels (0.2, 0.5 and 1.0 wt%) of a novel Al base Master Alloy containing Ti, C and Sr (synthesized in the authors’ laboratory) at 720 °C. The wear resistance of LM25 Alloy improves with the addition of this Master Alloy up to 0.5 wt%. It is observed that α-Al cell size and morphology of the eutectic silicon of LM25 Alloy have significant effect on the wear resistance of the Alloy.
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influence of thermo mechanical processing of al 5ti 1b Master Alloy on its grain refining efficiency
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2004Co-Authors: K Venkateswarlu, M Chakraborty, B S MurtyAbstract:The influence of extrusion and heat treatment after extrusion on the microstructural changes and the grain refining efficiency of Al-5Ti-1B; Master Alloy have been studied in detail. Extruded Al-5Ti-1B Master Alloy has resulted in significant refinement in TiAl3 Particle size and change in its morphology from plate like to blocky type. Mean particle size of TiAl3 has decreased with increase in the extrusion ratio. The grain refining performance of the Master Alloy has improved with increase in the extrusion ratio. These changes are attributed to the fracture of TiAl3 particles during extrusion, which results in an increase in the number of nucleating sites for Al. However, heat treatment of the extruded Master Alloy has reduced its grain refining performance. Heat treatment after extrusion at the highest extrusion ratio has resulted in the dissolution of TiAl3 and TiB2 particles in alpha-Al matrix, leading to poorer grain refining efficiency of the Master Alloy. (C) 2003 Elsevier B.V. All rights reserved.
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effect of hot rolling and heat treatment of al 5ti 1b Master Alloy on the grain refining efficiency of aluminium
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2001Co-Authors: K Venkateswarlu, B S Murty, M ChakrabortyAbstract:The influence of hot rolling and annealing of Al–5Ti–1B Master Alloy on its grain refining efficiency has been studied in detail. Both hot rolling and annealing improve the grain refining efficiency of the Master Alloy. Rolling results in the fracture of TiAl3 particles. The amount of deformation required for achieving good grain refinement decreases with increase in rolling temperature. Grain refining efficiency of the Master Alloy also increases with increase in annealing temperature. The improved grain refining efficiency of the Master Alloy on annealing is attributed to the increased fraction of TiAl3 and the possible formation of (Ti,Al)B2.
B S Murty - One of the best experts on this subject based on the ideXlab platform.
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al ti c sr Master Alloy a melt inoculant for simultaneous grain refinement and modification of hypoeutectic al si Alloys
Journal of Alloys and Compounds, 2009Co-Authors: B S Murty, M ChakrabortyAbstract:Abstract Present article is focused on the microstructural features of Al–Ti–C–Sr Master Alloy, an inoculant for simultaneous grain refinement and modification of hypoeutectic Al–Si Alloys. This Master Alloy is basically a metal matrix composite consisting of TiC and Al 4 Sr phases formed in situ in the Al-matrix. TiC particles initiate the refinement of primary α-Al through heterogeneous nucleation in molten hypoeutectic Al–Si Alloy, while Al 4 Sr phase dissolves in molten Al–7Si Alloy enriching the melt with Sr, which eventually leads to modification of eutectic silicon during solidification of the Al–7Si Alloy casting. Thus present Master Alloy serves in both ways, as a grain refiner and a modifier for hypoeutectic Al–Si Alloys.
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microstructural and wear behavior of hypoeutectic al si Alloy lm25 grain refined and modified with al ti c sr Master Alloy
Wear, 2006Co-Authors: B S Murty, M ChakrabortyAbstract:Abstract Present article reports the microstructure and wear behavior of grain refined and modified Al–7Si–0.3Mg (LM25) Alloy. Combined grain refinement and modification is achieved by inoculating LM25 melt with various inoculation levels (0.2, 0.5 and 1.0 wt%) of a novel Al base Master Alloy containing Ti, C and Sr (synthesized in the authors’ laboratory) at 720 °C. The wear resistance of LM25 Alloy improves with the addition of this Master Alloy up to 0.5 wt%. It is observed that α-Al cell size and morphology of the eutectic silicon of LM25 Alloy have significant effect on the wear resistance of the Alloy.
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influence of thermo mechanical processing of al 5ti 1b Master Alloy on its grain refining efficiency
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2004Co-Authors: K Venkateswarlu, M Chakraborty, B S MurtyAbstract:The influence of extrusion and heat treatment after extrusion on the microstructural changes and the grain refining efficiency of Al-5Ti-1B; Master Alloy have been studied in detail. Extruded Al-5Ti-1B Master Alloy has resulted in significant refinement in TiAl3 Particle size and change in its morphology from plate like to blocky type. Mean particle size of TiAl3 has decreased with increase in the extrusion ratio. The grain refining performance of the Master Alloy has improved with increase in the extrusion ratio. These changes are attributed to the fracture of TiAl3 particles during extrusion, which results in an increase in the number of nucleating sites for Al. However, heat treatment of the extruded Master Alloy has reduced its grain refining performance. Heat treatment after extrusion at the highest extrusion ratio has resulted in the dissolution of TiAl3 and TiB2 particles in alpha-Al matrix, leading to poorer grain refining efficiency of the Master Alloy. (C) 2003 Elsevier B.V. All rights reserved.
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effect of hot rolling and heat treatment of al 5ti 1b Master Alloy on the grain refining efficiency of aluminium
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2001Co-Authors: K Venkateswarlu, B S Murty, M ChakrabortyAbstract:The influence of hot rolling and annealing of Al–5Ti–1B Master Alloy on its grain refining efficiency has been studied in detail. Both hot rolling and annealing improve the grain refining efficiency of the Master Alloy. Rolling results in the fracture of TiAl3 particles. The amount of deformation required for achieving good grain refinement decreases with increase in rolling temperature. Grain refining efficiency of the Master Alloy also increases with increase in annealing temperature. The improved grain refining efficiency of the Master Alloy on annealing is attributed to the increased fraction of TiAl3 and the possible formation of (Ti,Al)B2.
Jun Wang - One of the best experts on this subject based on the ideXlab platform.
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microstructure and synthesis mechanism of al ti c sr Master Alloy
Transactions of Nonferrous Metals Society of China, 2010Co-Authors: Hongliang Zhao, Jun Wang, Yong Song, Shaokang GuanAbstract:Abstract Al-5Ti-0.5C-8Sr (mass fraction, %) Master Alloy was prepared using a melt reaction method. The microstructure and synthetic process of the Master Alloy were investigated by optical microscopy, X-ray diffraction, scanning electron microscopy and X-ray energy-dispersive spectrum. The results show that the Master Alloy is composed of a (Al), TiAl 3 , TiC, Al 4 Sr and Al-Ti-Sr phases. The synthesis mechanisms of the Master Alloy are as follows: TiAl 3 is formed through the reaction between K 2 TiF 6 and Al melt at 850 °C; when the melt was heated up to 1 200-1 300 °C, TiC was formed through the reaction: Ti+C(s)=TiC(s); Al 4 Sr was formed through the binary uniform reaction when Sr was added into the melt; after the following solidification process in the peritectic reaction: L(Al, Sr)+α(TiAl 3 )→β(Al-Ti-Sr), the enwrapped structure was formed with the outer layer of Al-Ti-Sr phase and the internal layer of TiAl 3 phase.
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grain refining of 409l ferritic stainless steel using fe ti n Master Alloy
Metallurgical and Materials Transactions A-physical Metallurgy and Materials Science, 2010Co-Authors: Chao Wang, Xiaoming Ruan, Jun WangAbstract:A deliberately prepared Fe-Ti-N Master Alloy was employed as a grain refiner for the 409L ferritic stainless steel in an attempt to refine the as-cast solidification structure. It was found that the average equiaxed grain size of the sample deceased from 1503 to 303 μm and the proportion of equiaxed grain zone increased from 14 to 100 pct with increasing the Fe-Ti-N Master Alloy addition level to 2.5 wt pct. Hence, this method may have good prospects for industrial applications.
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microstructure and grain refining performance of al 5ti 1b Master Alloy prepared under high intensity ultrasound
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2006Co-Authors: Jun WangAbstract:Abstract The microstructure and grain refining performance of an Al–5Ti–1B Master Alloy prepared under high-intensity ultrasound were investigated. With applying continuous high-intensity ultrasound vibrations in the reaction, the Al–5Ti–1B Master Alloy is successfully manufactured in 4 min. Compared with conventional Al–5Ti–1B Master Alloys, the mean size and the size spread of TiB 2 particles in the prepared Master Alloy are evidently decreased. The narrower particle size spread significantly improves the grain refining performance of the Master Alloy, which proves the calculation predictions by Greer. Consequently, the limiting grain size of commercial purity aluminium refined by the new Master Alloy can reach 45 μm.
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influence of high intensity ultrasound on grain refining performance of al 5ti 1b Master Alloy on aluminium
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2005Co-Authors: Ke Li, Jun WangAbstract:Abstract The microstructure and grain refinement of an Al–Ti–B Master Alloy treated with high-intensity ultrasound in fabrication and remelting process have been investigated. The high-intensity ultrasound applied in remelting of commercial Al–5Ti–1B improves the microstructure and grain refinement performance of the Master Alloy. The reaction among halide salts and aluminium is accelerated when the melt is treated with ultrasound. With united ultrasonic treatments in fabrication and solidification of the Master Alloy, not only the morphology of TiAl3 phase is improved, but also the particles in the agglomeration are in spawn-like form instead, which further improves the performance of the Master Alloy. The effects of acoustic cavitation and streaming on the Al–5Ti–1B Master Alloy are also discussed.
