Effects of Ti Powder Additions in Melt-SHS Process on the Performance of Al-Ti-B Grain Refiner Alloys

2016 ◽  
Vol 877 ◽  
pp. 121-126
Author(s):  
He Li ◽  
Li Hua Chai ◽  
Zhi Lei Xiang ◽  
Yong Shuang Cui ◽  
Zi Yong Chen
Keyword(s):  
Master Alloy ◽  
Reaction Rate ◽  
Grain Refining ◽  
Grain Refiner ◽  
Temperature Synthesis ◽  
Refining Efficiency ◽  
Strip Shape ◽  
High Temperature Synthesis ◽  
Al Powder ◽  
Ti Powder

Melt-SHS (Self-propagating High-temperature Synthesis) was used for the preparation of Al–5Ti–1B master alloy. The quality ratio of Ti powder/TiO2 in initial powder mixture was varied from 0:1 to 1:0. The AES, XRD and SEM were applied to evaluate the microstructure and phase componet. The results showed that the Al-5Ti-1B master alloy could be successful produced by the reaction of Al powder, TiO2 and H3BO3 in Al melt, while the reaction rate was slow. The microstructure mainly presents the TiAl3 particles with long strip shape. A significant improvement was noted both in reaction rate and in the grain refining efficiency when Ti powder was added to the reactants and the optimized ratio of Ti powder/TiO2 was 2:3. The TiAl3 particles were reduced and the grain refining efficiency turned bad when Ti powder was totally used to supply Ti

Effect of C/Ti Ratio and Al Powder Size on Microstructure and Performance of Al-Ti-C Grain Refiner

2007 ◽  
Vol 353-358 ◽  
pp. 2981-2984
Author(s):  
Chun Xiang Xu ◽  
Li Ping Liang ◽  
Bin Feng Lu ◽  
Jin Shan Zhang ◽  
Wei Liang
Keyword(s):  
Powder Size ◽  
Grain Refining ◽  
Grain Refiner ◽  
Casting Method ◽  
High Temperature Synthesis ◽  
Method Effects ◽  
Refining Performance ◽  
Al Powder ◽  
And Performance ◽  
Microstructure And Performance

Al-Ti-C grain refiners have been prepared by combining self-propagating high-temperature synthesis (SHS) technique and melting-casting method. Effects of Al powder size and C/Ti ratio on the microstructures and grain-refining efficiency of Al-Ti-C grain refiners were studied by OM, XRD, SEM and EDS. The results show that when Al powder size is fine, and C/Ti ratio is 1: 8, SHS reaction among the mixed powders can easily carry on in the melt. As a result, the prepared grain refiner consists of blocky Al3Ti and fine TiC particles distributed in Al matrix, and exhibits excellent grain refining performance on commercially pure Al.

Study on Preparation of Ti Powder by Self-Propagating High-Temperature Synthesis (SHS) with Magnesiothermit Reductive Process

2008 ◽  
Vol 575-578 ◽  
pp. 1086-1092
Author(s):  
Peng Lin Zhang ◽  
Tian Dong Xia ◽  
Guo Dong Zhang ◽  
Li Jing Yan
Keyword(s):  
Reaction Rate ◽  
Combustion Temperature ◽  
Combustion Process ◽  
Green Compact ◽  
Reaction Products ◽  
Technological Parameters ◽  
Solid Reaction ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Ti Powder

The combustion process of Mg-TiO2 system was preliminarily investigated from three aspects of thermodynamics, reaction kinetics and the technological parameters. The result indicates that the adiabatic temperature of Mg-TiO2 system is between 2060K and 2140K because the major existent modalities of TiO2 is the rutile and anatase, this meets the empirical criterion that the SHS reaction will be self-sustaining; The solid-solid reaction occurs at about 767K; Ti powders can be produced only when the ratio between Mg and TiO2 arrives at 2.9:1; The higher the vacuum, the more complete the reaction; The combustion temperature arrives at its peak when the pressure of green compact arrives at 250MPa; the velocity of the combustion wave increases with the augmentation of the pressure of green compact. So the proper control of the technological parameters can change the reaction temperature, reaction rate and the components of reaction products.

Effect of TiH2 on the Microstructures and Refining Performance of Al-Ti-C Master Alloy

2007 ◽  
Vol 561-565 ◽  
pp. 329-332 ◽  
Author(s):  
Hong Yu Zhuang ◽  
Xue Min Pan
Keyword(s):  
Thermal Decomposition ◽  
Master Alloy ◽  
Thermal Reaction ◽  
Grain Refining ◽  
Temperature Synthesis ◽  
Obvious Effect ◽  
High Temperature Synthesis ◽  
Master Alloys ◽  
Refining Test ◽  
Refining Performance

Al-Ti-C master alloy with or without the TiH2 was prepared by Self-propagating High-temperature Synthesis (SHS) induced by laser. The phases, composition, microstructure morphologies of master alloy and its thermal reaction process were investigated by XRD, EPMA, DTA and SEM. The results show that adding TiH2 has obvious effect in promoting the synthesizing reaction of Al-Ti-C master alloys. Active Ti atoms and catalyzing H atoms released by TiH2 thermal decomposition cause critical reacting temperature of the SHS decreasing. The addition of TiH2 affects the morphologies and distribution of TiAl3 and TiC particles (size of TiC was smaller than 1μm in diameter), and restrains the congregating tendency of TiC particles. The refining test on aluminum indicates that master alloys with TiH2 possesses more excellent grain refining perfprmance than without, because of the composition and morphology of the master alloy is cut out for refining processing.

scholarly journals Self-propagating High-temperature Synthesis of Materials Based on Tungsten Carbide for One-Pot Hydrolysis-Hydrogenolysis of Cellulose Into Ethylene Glycol and 1,2-Propylene Glycol

2019 ◽  
pp. 269-281
Author(s):  
Nikolay V. Gromov ◽  
Тatiana B. Medvedeva ◽  
Ivan А. Lukoyanov ◽  
Alekasandr А. Zhdanok ◽  
Vladimir А. Poluboyarov ◽  
...  
Keyword(s):  
High Temperature ◽  
Ethylene Glycol ◽  
Tungsten Carbide ◽  
Propylene Glycol ◽  
Reaction Rate ◽  
Total Yield ◽  
Temperature Synthesis ◽  
One Pot ◽  
Catalytic Systems ◽  
High Temperature Synthesis

Catalytic systems based on tungsten carbide (WnC) containing mainly W2C were obtained by the method of self-propagating high-temperature synthesis from a mechanochemically activated mixture of tungsten oxide, metallic magnesium, carbon black and CaCO3. The phase composition of the formed materials was shown to depend on the amount of CaCO3. The catalytic properties of the materials were tested in the hydrolysis-hydrogenation of cellulose to ethylene glycol (EG) and 1,2-propylene glycol (PG). It was established that in the presence of WnC the main products of the reaction were EG and PG with a ratio of PG/EG – 1.5-1.8. The deposition of nickel nanoparticles on the WnC surface increased the reaction rate and product yields. The maximum total yield of diols was 47.1 mol. %.

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 Al-Ti-B4C materials obtained by high-temperature synthesis and used as a master-alloy for aluminum

2018 ◽  
Vol 243 ◽  
pp. 00010 ◽  
Author(s):  
Ilya Zhukov ◽  
Vladimir Promakhov ◽  
Yana Dubkova ◽  
Alexey Matveev ◽  
Mansur Ziatdinov ◽  
...  
Keyword(s):  
High Temperature ◽  
Burning Rate ◽  
Powder Mixture ◽  
Pure Aluminum ◽  
Al Alloy ◽  
Initial Powder ◽  
Temperature Synthesis ◽  
Al Content ◽  
High Temperature Synthesis ◽  
Al Powder

The paper presents microstructure, composition, and burning rate of Al alloy produced by high-temperature synthesis (SHS) from powder mixture Al-Ti-B4C with different concentration of Al powder. It has been established that the phase composition of materials obtained at gas-free combustion includes TiB2, Al, and TiC. It is shown that Al content growth powder in initial Al-Ti- B4C mixture from 7.5 to 40 wt.% reduces the burning rate of the powder from 9*10-3 to 1.8*10-3 m/s. For the system consisting of 60 wt.% of (Ti + B4C) and 40 wt.% of Al there is the increase in the porosity of the compacted initial powder mixture from 30 to 51 and reduction in the burning rate from 1.8 * 10-3 to 1 * 10-3 m/s. The introduction of 0.2 wt.% of the obtained SHS materials into the melt of pure aluminum causes reduction of the grain size of the resulting alloy from 1200 to 410 μm.

scholarly journals Preparation of Ferrotitanium Using Ilmenite with Different Reduction Degrees

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 962 ◽  
Author(s):  
Zixian Gao ◽  
Gongjin Cheng ◽  
He Yang ◽  
Xiangxin Xue ◽  
Jongchol Ri
Keyword(s):  
Melting Point ◽  
Aluminum Content ◽  
Synthesis Method ◽  
Al2o3 Content ◽  
Reduction Degree ◽  
High Melting Point ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Al Powder ◽  
Constant Addition

The effect of ilmenite with different reduction degrees on the production of ferrotitanium, using a self-propagation high-temperature synthesis method with aluminum as the reducing agent, was investigated. Increasing the degree of reduction not only contributed to lower consumption of aluminum, but also lowered the oxygen content and improved the grades of titanium and iron in the ferrotitanium. The aluminum content of the ferrotitanium increased with an increase in the extent of reduction of ilmenite, so the Al2O3 content formed in the slag decreased with the constant addition of CaO and CaF2 to the Al powder. This decreased relatively the content of high-melting-point CaAl12O19 and increased the contents of low-melting-point CaAl2O4 and CaF2 in the slag, thereby promoting the separation of ferrotitanium and slag. Improving the reduction degree of ilmenite is beneficial to the preparation of ferrotitanium.

The Behavior of AlTiC Master Alloys in Grain Refining of Commercial and High Pure Aluminum

2005 ◽  
Vol 475-479 ◽  
pp. 313-316
Author(s):  
Jian Guo Li ◽  
Min Huang ◽  
Zimu Shi ◽  
Dong Yu Liu
Keyword(s):  
Master Alloy ◽  
Heterogeneous Nucleation ◽  
Pure Aluminum ◽  
Grain Refining ◽  
Refining Efficiency ◽  
Master Alloys

The AlTiC master alloy has been prepared in different components to refine 99.8%Al and 99.98％Al, then compared to two typical Al5Ti1B in refining efficiency and the grain nuclear. The result showed that the refining efficiency seemed better if the nucleation of high pure aluminum revealed complexity and variety. It may due to that the latency heterogeneous nucleation was efficient on the whole, consequently accelerated refining efficiency.

Refinement of TiB2 in Al-Ti-B Grain Refiner Alloys by Ultrasound and the Effect on Al Grain Size

2010 ◽  
Vol 654-656 ◽  
pp. 958-961 ◽  
Author(s):  
Da Shu ◽  
Bao De Sun ◽  
Jia Wei Mi ◽  
Patrick S. Grant
Keyword(s):  
Reaction Rate ◽  
Grain Refining ◽  
Commercial Purity ◽  
Grain Refiner ◽  
Mean Diameter ◽  
Refining Performance ◽  
Narrow Width ◽  
Free Growth ◽  
Fluoride Salts ◽  
Tib2 Particles

High-intensity ultrasound was applied during the preparation of an Al-5Ti-1B master alloy when reacting fluoride salts with molten Al. The reaction rate was significantly increased with TiB2 particles of much reduced mean diameter and narrow width spread produced in ~4 minutes. The improved grain refining performance of the TiB2 in a commercial purity Al was studied and modelled using free growth model. The increased number and reduced size of TiB2 particles provided an enhanced grain refining capability.

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