scholarly journals Preparation Process and Phase Transformation of Al-5Ti-0.25C Master Alloy Adopting Ti Machining Chips

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5783
Author(s):  
Sanbo Li ◽  
Chunfang Zhao ◽  
Fei Wang ◽  
Maoliang Hu ◽  
Zesheng Ji ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Master Alloy ◽  
Molten Aluminum ◽  
Energy Dispersive Spectrometer ◽  
Optical Microscope ◽  
Preparation Process ◽  
Simple Method ◽  
Master Alloys

The refining performance of Al-Ti-C master alloys is substantially compromised by the inferior wettability between graphite and molten aluminum. In this paper, the Al-5Ti-0.25C master alloy was successfully prepared by reacting Ti machining chips, graphite, and molten aluminum. In order to determine a simple method of improving the wettability, the optimal preparation process and phase transformation of the Al-5Ti-0.25C master alloy were investigated using an optical microscope, X-ray diffractometer, and scanning electron microscope equipped with an energy dispersive spectrometer. The results show that the feeding method using a prefabricated block made from Ti chips, Al chips, and graphite effectively improves the wettability between graphite and molten aluminum and increases the recovery rate of graphite. When the reaction temperature is low (1223 K), the agglomeration of TiAl3 is caused. When the reaction temperature is high (1373 K), the morphology of TiAl3 changes from block-like to needle-like and increases its size. Further, a short reaction time (30 min) results in the incomplete dissolution of the Ti chips, while a long reaction time (90 min) causes the TiAl3 to transform into needle-like morphologies. The microstructural observation of undissolved Ti chips shows that TiAl3 and TiC are formed around it, which proves the transformation of Ti chips to TiAl3 and TiC. In addition, the enrichment of TiC and Al4C3 was observed in the vicinity of TiAl3, and a reaction model for the formation of TiC from the reaction of Al4C3 and TiAl3 was presented.

Preparation and Characterization of Al-1Ti-3B Master Alloys by Salt Route and Evaluation of their Grain Refining Performance on Al-7Si Alloys

2014 ◽  
Vol 790-791 ◽  
pp. 173-178 ◽  
Author(s):  
Virupaxi Auradi ◽  
Shivaputrappa Amarappa Kori
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Master Alloy ◽  
Reaction Times ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Grain Refining ◽  
Refining Efficiency ◽  
Master Alloys ◽  
Refining Performance

In the present work, ternary Al-1Ti-3B master alloys were prepared in an induction furnace via salt route which involves reaction between preheated halide salts (K2TiF6 and KBF4) and liquid molten Al. During preparation process parameters such as reaction temperatures of 800, 900, 1000°C and reaction times 45, 60, 75 min. have been used to study the influence of these parameters on the morphology of particles present in the master alloy and inturn on the grain refining efficiency of Al-7Si alloy. The indigenously prepared master alloys were characterized by chemical analysis; particles size analysis, XRD and SEM/EDX microanalysis. Results of particle size analysis suggest that the sizes of the particles present in Al-1Ti-3B master alloys increases with increase in reaction temperature (800-1000°C) and reaction time (45-75 min.). However, the population of the particles having sizes less than 10µm decreases with increase in reaction time and temperature. Further, SEM/EDX studies revealed different morphologies of the particles present in the master alloy when processed at different reaction temperatures and reaction times. Further, the performances of the above-prepared master alloys were assessed for their grain refining efficiency on Al-7Si alloy by DAS analysis and by CACCA studies. Results of grain refinement studies and CACCA studies suggest that, Al-1Ti-3B master alloy prepared at reaction temperature of 800°C with a reaction time of 60min. shows better grain refining performance on Al-7Si alloy when compared to the same master alloy prepared under different processing conditions.

Influence of Reaction Temperature for the Manufacturing of Al-3Ti and Al-3B Master Alloys and their Grain Refining Efficiency on a Al-7Si Alloy

2007 ◽  
Vol 29-30 ◽  
pp. 111-115 ◽  
Author(s):  
S.A. Kori ◽  
V. Auradi
Keyword(s):  
Size Distribution ◽  
Grain Refinement ◽  
Reaction Temperature ◽  
Master Alloy ◽  
Induction Furnace ◽  
Grain Refining ◽  
Refining Efficiency ◽  
Master Alloys ◽  
Halide Salts ◽  
Titanium Fluoride

In the present work binary Al-3Ti and Al-3B master alloys were prepared at different reaction temperatures in an induction furnace by the reaction of halide salts like potassium fluoborate and potassium titanium fluoride with liquid molten Al. The indigenously developed master alloys were used for grain refinement studies of Al-7Si alloy and evaluated for their grain refining ability by CACCA studies. The present results suggest that, the reaction temperature influences the size, size distribution and morphology of the intermetallic (Al3Ti in Al-3Ti, and AlB2/AlB12 in Al-3B) particles present in Al-3Ti and Al-3B master alloys. Grain refinement studies of Al-7Si alloy reveal that, Al-3Ti and Al-3B master alloys prepared at 8000C-60 min. have shown better grain refining efficiency on Al- 7Si alloy when compared to the master alloys prepared at 9000C-60 min and 10000C-60 min respectively. In addition, B-rich Al-3B master alloy shows efficient grain refinement than Ti rich Al- 3Ti master alloy.

scholarly journals The Formation Mechanism and Characterization of Al-Si Master Alloys from Sodium Fluosilicate

2019 ◽  
Vol 26 (2) ◽  
pp. 185-191
Author(s):  
Gamal Mohamed Attia MAHRAN ◽  
Abdel-Nasser Mohamed OMRAN ◽  
El-Sayed Sedek ABU SEIF
Keyword(s):  
Reaction Time ◽  
Molten Aluminum ◽  
Volume Fraction ◽  
Eutectic Point ◽  
Effect Of Temperature ◽  
Primary Si ◽  
Master Alloys ◽  
Sodium Fluosilicate ◽  
Mechanism Of The Reaction

A modified Al-Si alloy containing up to 15 wt.% Si has been obtained from the reaction of sodium fluosilicate (Na2SiF6) with molten aluminum. This work attempted to estimate the mechanism of the reaction of Na2SiF6 with molten aluminum to produce Al-Si alloys. The effect of temperature, Na2SiF6/Al Wt ratio and reaction time on the formation of Al-Si alloy were investigated. The thermodynamic data, kinetic and rate of the reaction were studied. The results showed the possibility of the reaction between Na2SiF6 and molten aluminum thermodynamically, and that this reaction might be controlled chemically. The current study aims to optimize the factors that affecting the preparation of a modified Al-Si alloy from a reduction of sodium fluosilicate using molten aluminium. Temperature 950 oC, reaction time 20 – 25 min and Na2SiF6/Al Wt ratio related to the applied Si percentage. The prepared alloys could be modified due to the presence of Na2SiF6 in the used material as a source of sodium in response to modifying the produced Al-Si alloys. The microstructure by using LOM, SEM, and EDX proved that the needle-like silicon converts to fine fibrous. The volume fraction of primary Si reduces and the eutectic point moves to a higher silicon concentration. The modification improves the wear characteristics and increases the tensile and hardness.

scholarly journals Extraction of alumina from alumina rich coal gangue by a hydro-chemical process

2020 ◽  
Vol 7 (4) ◽  
pp. 192132 ◽  
Author(s):  
Quancheng Yang ◽  
Fan Zhang ◽  
Xingjian Deng ◽  
Hongchen Guo ◽  
Chao Zhang ◽  
...  
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Chemical Process ◽  
Energy Dispersive Spectrometer ◽  
Coal Gangue ◽  
Added Value ◽  
High Alumina ◽  
Mass Ratio ◽  
X Ray Diffraction ◽  
X Ray

Vast quantities of gangue from coal mining and processing have accumulated over the years and caused significant economic and environmental problems in China. For high added-value utilization of alumina rich coal gangue (ARCG), a mild hydro-chemical process was investigated to extract alumina. The influences of NaOH concentration, mass ratio of alkali to gangue, reaction temperature and reaction time were systematically studied. An alumina extraction rate of 94.68% was achieved at the condition of NaOH concentration 47.5%, alkali to gangue ratio of 6, reaction temperature of 260°C and reaction time of 120 min. The obtained leaching residues were characterized through X-ray diffraction, scanning electron microscopy and energy-dispersive spectrometer. Research confirmed that kaolinite the main alumina-bearing phase of ARCG can be decomposed and transformed to Na 8 Al 6 Si 6 O 24 (OH) 2 (H 2 O) 2 and Ca 2 Al 2 SiO 6 (OH) 2 at relatively low temperature and short reaction time. Additionally, Na 8 Al 6 Si 6 O 24 (OH) 2 (H 2 O) 2 and Ca 2 Al 2 SiO 6 (OH) 2 are unstable and will transform to alumina-free phase NaCaHSiO 4 under the optimal conditions, which is the major reason for high alumina extraction rates.

scholarly journals Investigation of Microstructure of Al-5Ti-0.62C System and Synthesis Mechanism of TiC

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 310 ◽  
Author(s):  
Wanwu Ding ◽  
Taili Chen ◽  
Xiaoyan Zhao ◽  
Yan Cheng ◽  
Xiaoxiong Liu ◽  
...  
Keyword(s):  
Master Alloy ◽  
Pure Aluminum ◽  
Preparation Process ◽  
Synthesis Mechanism ◽  
Microstructure Transformation ◽  
Master Alloys ◽  
Refining Performance ◽  
Commercial Pure Aluminum ◽  
Positive Effect

Al-Ti-C master alloys have been widely investigated by various researchers. However, their refining effectiveness is still severely compromised by the preparation process. In this work, the aluminum melt in-situ reaction was carried out to synthesize the Al-5Ti-0.62C, and its refining performance was estimated. The thermodynamics calculation and differential scanning calorimeter experiment were used to investigate the synthesis mechanism of TiC. Quenching experiment was conducted to explore phase and microstructure transformation of the Al-5Ti-0.62C system. The results show that the main phases of Al-5Ti-0.62C master alloys are α-Al, Al3Ti, and TiC and it has a positive effect on commercial pure aluminum refining. Commercial pure aluminum is completely refined into the fine equiaxed structure by adding 0.3% Al-5Ti-0.62C master alloy. TiC particles mainly distribute in the grain interior and grain boundaries. The excess Ti came from the dissolution of Al3Ti spreading around TiC and finally forming the Ti-rich zone to promote the nucleation of α-Al. The experiments certified that TiC was formed by the reaction between solid C and excess Ti atoms. The main reactions in the Al-5Ti-0.62C system were that solid Al is transferred into liquid Al, and then liquid Al reacted with solid Ti to form the Al3Ti. At last, the release of a lot of heat promotes the formation of TiC which formed by the Ti atoms and solid C.

scholarly journals Effect of Eutectic Mg2Si Phase Modification on the Mechanical Properties of Al-8Zn-6Si-4Mg-2Cu Cast Alloy

Metals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 32 ◽  
Author(s):  
Byung Joo Kim ◽  
Sung Su Jung ◽  
Ji Hoon Hwang ◽  
Yong Ho Park ◽  
Young Cheol Lee
Keyword(s):  
Mechanical Properties ◽  
Master Alloy ◽  
Base Alloy ◽  
Cast Alloy ◽  
Energy Dispersive Spectrometer ◽  
Chinese Script ◽  
Phase Modification ◽  
Master Alloys ◽  
Polygonal Shape ◽  
Tib2 Particles

The modification effect of Al-5Ti-1B master alloy on eutectic Mg2Si in Al-Zn-Si-Mg system alloy was investigated in this study. The microstructure shows that an extreme effect can be achieved after the addition of Al-5Ti-1B master alloy into the base alloy. The morphology of eutectic Mg2Si changed from Chinese script to fine polygonal shape, and the size was refined from over 50 μm to under 10 μm. This morphology change is believed to be due to TiB2 particles existing in Al-5Ti-1B master alloy, and the presence of TiB2 particles inside the modified Mg2Si was confirmed by scanning electron microscope/energy dispersive spectrometer (SEM/EDS) observation. The mechanical properties were also improved by the addition of Al-5Ti-1B master alloys. This study investigated the reason for the improvement in mechanical properties with the modification of the microstructure.

Preparation of Ultrafine Al(OH)3 Powders from Scrap Aluminum

2013 ◽  
Vol 544 ◽  
pp. 13-16
Author(s):  
Jing Xu
Keyword(s):  
Reaction Time ◽  
Sulphuric Acid ◽  
Reaction Temperature ◽  
Raw Material ◽  
Homogeneous Precipitation ◽  
Preparation Process ◽  
Optimal Conditions ◽  
Ultrafine Powders ◽  
Infrared Spectrometer ◽  
Scrap Aluminum

The homogeneous precipitation pathway was explored to synthesize ultrafine powders of Al(OH)3. In the experiment, the scrap aluminum were used as raw material . The effects of reaction time, reaction temperature, stirring speed, concentration of sulphuric acid and dispersant on the preparation process were investigated. The results showed that ultrafine Al(OH)3 powders can be yielded and well-controlled under the following optimal conditions: the concentration of sulphuric acid 3.0 mol•L-1, reaction temperature 0-4 °C, stirring speed 900 r.min-1 and reaction time 15 min. The diameter less than 100nm of sphericity Al(OH)3 particles with the narrow distribution were successfully obtained. The Al(OH)3 powders was analyzed with scanning electron microscopy , infrared spectrometer. The Al(OH)3 powders have good dispersancy and purity is more than 90%. The operation of the experiment was very simple, and the particles were separated easily.

The Effect of Process Parameter on the Second Phase Particles in Al-Ti-B Master Alloys

2014 ◽  
Vol 900 ◽  
pp. 100-104
Author(s):  
Liang Jie Wei ◽  
Hua Hu ◽  
Zhi Liu Hu ◽  
Yan Jun Zhao
Keyword(s):  
Reaction Time ◽  
Process Parameters ◽  
Master Alloy ◽  
Pure Titanium ◽  
Process Parameter ◽  
Second Phase ◽  
Grain Refiner ◽  
Second Phase Particles ◽  
Master Alloys

Al-Ti-B master alloy is an efficient and practical aluminum grain refiner. This paper studies the effect of process parameter on the Second Phase Particles distributions and shape in Al-Ti-B Master Alloys by casting of pure titanium particale method. Emphatically studied three factors of feeding order, superheating temperature and reaction time , then the reasonable process parameters are put forward.

Study on the Interaction of Rare Earth (La) and Strontium with Titanium and Boron in the Al-Ti-B Based Master Alloy

2011 ◽  
Vol 311-313 ◽  
pp. 1017-1020 ◽  
Author(s):  
Ji Hua Peng ◽  
Yao Feng Deng ◽  
Jian Ting He
Keyword(s):  
Master Alloy ◽  
Optical Microscope ◽  
Critical Ratio ◽  
Reaction Products ◽  
X Ray ◽  
Master Alloys ◽  
Constituent Phase ◽  
Probe Microscope ◽  
Halide Salts ◽  
Rare Earth La

Al-Ti-B-Sr-RE master alloys were prepared firstly by the reaction of complex halide salts with molten aluminum at 800°C, and then the addition of Al-RE and Al-Sr master alloys into the melt. The constituent phase and microstructure were characterized by XRD, optical microscope (OM) and scanning electron microscope (SEM). The element content was analyzed by spectrometer, X-ray fluorescence spectrometry and electron probe microscope. Ti2Al20RE, SrB6, LaB6, Al4Sr and Al11La3are the constituent phases in these master alloys. The constituent phases containing Sr and RE in the Al-Ti-B master alloy depend on the ratio of Ti and B. The critical ratio of Ti and B is 2.2:1. Obviously, SrB6and LaB6phases are the reaction products of AlB2with Sr or La during master alloy fabrication. The two layer lump-like Ti-Al-RE particles formation mechanism is proposed.

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