scholarly journals Mechanism of the Mg3Bi2 Phase Formation in Pb-Free Aluminum 6xxx Alloy with Bismuth Addition

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 424
Author(s):  
Simon Rečnik ◽  
Milan Bizjak ◽  
Jožef Medved ◽  
Peter Cvahte ◽  
Blaž Karpe ◽  
...  
Keyword(s):  
Melting Furnace ◽  
Microstructural Characterization ◽  
Induction Melting ◽  
Microstructure Development ◽  
Electric Resistance ◽  
Grain Refiner ◽  
Melt Temperature ◽  
Preparation Methods ◽  
Solidification Sequence ◽  
Preparation Route

In the present work, free-cutting aluminum alloy AA6026 with 1.1 wt.% bismuth addition was fabricated by different melt preparation methods in order to investigate whether the melt preparation route affects the solidification sequence and thus has an influence on the machinability of the alloy. All experiments were designed to simulate variable industrial conditions: addition of bismuth in an induction melting furnace, addition of bismuth in an electric resistance holding furnace, addition of bismuth together with grain refiner, effect of holding time and melt temperature before casting. Detailed thermodynamic analyses (DSC, Thermo-Calc) and microstructural characterization (SEM-EDS, XRD) have been performed to explain the solidification sequence, microstructure development and especially formation of the intermetallic Mg3Bi2 phase.

Synthesis and Forming of Titanium Matrix Composites by Casting Route

2007 ◽  
Vol 334-335 ◽  
pp. 297-300
Author(s):  
Si Young Sung ◽  
Bong Jae Choi ◽  
Young Jig Kim
Keyword(s):  
Electron Microscopy ◽  
Melting Furnace ◽  
Vacuum Induction Melting ◽  
Induction Melting ◽  
Matrix Composites ◽  
Titanium Matrix ◽  
Titanium Matrix Composites ◽  
Electron Probe Micro Analyzer ◽  
Transmission Electron

The aim of this study is to evaluated the possibility of the in-situ synthesized (TiC+TiB) reinforced titanium matrix composites (TMCs) for the application of structural materials. In-situ synthesis and casting of TMCs were carried out in a vacuum induction melting furnace with Ti and B4C. The synthesized TMCs were characterized using scanning electron microscopy, an electron probe micro-analyzer and transmission electron microscopy, and evaluated through thermodynamic calculations. The spherical TiC plus needle-like and large, many-angled facet TiB reinforced TMCs can be synthesized with Ti and B4C by a melting route.

Cycling Stability Performance of La0.75Mg0.25Ni3.5Si0.10 Hydrogen Storage Alloy in Discharge–Charge System

2014 ◽  
Vol 13 (05n06) ◽  
pp. 1460003
Author(s):  
Zhaojiang Liu ◽  
Lei Huang ◽  
Qi Wan ◽  
Xu Li ◽  
Ma Guang ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Electrochemical Properties ◽  
Melting Furnace ◽  
Test System ◽  
Cycling Stability ◽  
Hydrogen Storage Alloy ◽  
Vacuum Induction Melting ◽  
Induction Melting ◽  
Stability Performance ◽  
Charge Discharge

La 0.75 Mg 0.25 Ni 3.5 Si 0.10 hydrogen storage alloy was prepared by vacuum induction melting furnace and subsequently heated treatment at 940°C for 8 h and cooled to room temperature in the oven. The electrochemical properties of La 0.75 Mg 0.25 Ni 3.5 Si 0.10 compound were measured by LAND CT2001A battery test system. The morphologies of the samples were characterized by scanning electron microscopy (SEM). The surface state of samples was analyzed by X-ray photoelectron spectroscopy (XPS). It was found that the charge–discharge rate plays the key impact on the cycling stability of the alloy. During the cycle test, the prepared La 0.75 Mg 0.25 Ni 3.5 Si 0.10 compound presented an excellent capacity retention at the charge–discharge of 1 C while the capacity of sample declined rapidly at 0.2 C. The excellent cycling stability performance of La 0.75 Mg 0.25 Ni 3.5 Si 0.10 electrode at 1 C could be attributed to the less powder and less oxidation of surface effective active elements. The pulverization inevitably leads to the separation of the part of the cracking alloy and the electrode, resulting in reduction of the effective active substance and increasing attenuation of the capacity per cycle. In addition, on the analysis of the different cut-off potential effects on the electrode, it was found that the La 0.75 Mg 0.25 Ni 3.5 Si 0.10 electrode shows good comprehensive electrochemical properties at 1 C cut-off 0.6–0.7 V. During charging, heavy overcharge will not be conducive to cycling stability performance during the charging test.

Deformation of the Aluminum Bath Surface in an Induction Melting Furnace

2015 ◽  
pp. 999-1004
Author(s):  
Akshay Bansal ◽  
Pierre Chapelle ◽  
Yves Delannoy ◽  
Emmanuel Waz ◽  
Pierre Le Brun ◽  
...  
Keyword(s):  
Melting Furnace ◽  
Bath Surface ◽  
Induction Melting

Deformation of the Aluminum Bath Surface in an Induction Melting Furnace

2015 ◽  
pp. 997-1004
Author(s):  
Akshay Bansal ◽  
Pierre Chapelle ◽  
Yves Delannoy ◽  
Emmanuel Waz ◽  
Pierre Le Brun ◽  
...  
Keyword(s):  
Melting Furnace ◽  
Bath Surface ◽  
Induction Melting

Effects of Impurities Distribution on the Crystal Structure and Electrical Properties of Multi-Crystalline Silicon Ingots

2011 ◽  
Vol 675-677 ◽  
pp. 101-104
Author(s):  
Qi Zhi Xing ◽  
Wei Dong ◽  
Shu Ang Shi ◽  
Guo Bin Li ◽  
Yi Tan
Keyword(s):  
Electrical Properties ◽  
Minority Carrier ◽  
Crystalline Silicon ◽  
Melting Furnace ◽  
Minority Carrier Lifetime ◽  
Vacuum Induction Melting ◽  
Induction Melting ◽  
Columnar Crystal ◽  
P Type ◽  
Crystal Region

Multi-crystalline silicon ingots were prepared by directional solidification using vacuum induction melting furnace. The content of aluminum and iron deeply decreased in the columnar crystal region of the multi-crystalline silicon ingots. The columnar crystal growth broke off corresponded to the iron contents sharply increased. The height of columnar crystal in the silicon ingots related to the pulling rates had been clarified by the constitutional supercooling theory. The maximum of the resistivity and the minority carrier lifetime closed to the transition zone where the conductive type changed from p-type to n-type in silicon ingots. Further analysis suggested that the electrical properties were related to the contents of shallow level impurities aluminum, boron and phosphorus.

scholarly journals Effect of Melt Temperature on the Effectiveness of the Grain Refining in Al-Si Castings

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
A. M. Samuel ◽  
S. S. Mohamed ◽  
H. W. Doty ◽  
S. Valtierra ◽  
F. H. Samuel
Keyword(s):  
Grain Size ◽  
Dendritic Structure ◽  
Grain Refining ◽  
Liquid Temperature ◽  
Grain Refiner ◽  
Dendrite Morphology ◽  
Melt Temperature ◽  
Strong Affinity ◽  
Rounded Form ◽  
Molten Liquid

The results inferred from the present work show that Al3Ti phase has a strong affinity to react with silicon (Si) in the molten alloy leading to formation of (Al,Si)3Ti phase instead. This reaction is independent of the grain refiner type. The molten liquid temperature would change its morphology from platelets at 750°C into dendritic structure at 950°C. It has also been observed that (Al,Si)3Ti phase platelets precipitate within the α-aluminum dendrites, whereas TiB2 or AlB2 particles are released into the surrounding interdendritic regions. Introduction of the grain refiner, regardless its type, would cause change in the α-aluminum dendrite morphology from an elongated to a more rounded form. The results also reveal that addition of 100 ppm B will reduce the initial grain size by ∼85% which is more than the effect of addition of 0.2%Ti in the form of Al-10%Ti (about 65%). Elimination of undercooling is important to obtain the maximum grain refining effect.

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