Synthesis mechanism of an Al-Ti-C grain refiner master alloy prepared by a new method

2003 ◽  
Vol 34 (8) ◽  
pp. 1727-1733 ◽  
Author(s):  
B. Q. Zhang ◽  
L. Lu ◽  
M. O. Lai ◽  
H. S. Fang ◽  
H. T. Ma ◽  
...  
Keyword(s):  
Master Alloy ◽  
New Method ◽  
Grain Refiner ◽  
Synthesis Mechanism

Research on Synthesizing Process under Ultrasound Coupling and Refining Performance of Al-Ti-C Grain Refiner

2012 ◽  
Vol 217-219 ◽  
pp. 377-381 ◽  
Author(s):  
Ying Long Li ◽  
Fu Rong Cao ◽  
Li Jin
Keyword(s):  
High Temperature ◽  
Grain Refinement ◽  
Master Alloy ◽  
Reduction Method ◽  
High Energy ◽  
Experimental Results ◽  
Reaction Synthesis ◽  
Grain Refiner ◽  
Synthesis Mechanism ◽  
Refining Performance

The microstructural characters and refining property of Al-Ti-C grain refinement alloy prepared by ultrasound coupling method were studied by analytical means such as SEM, and the reaction synthesis mechanism of Al-Ti-C grain refinement was discussed. Experimental results show that the Al-Ti-C alloy refiner using “thermite reduction method” under high-energy ultrasound was prepared experimentally. Its microstructure character is that master alloy has smaller size of TiC, its quantities are larger and are dispersed. Melt reaction is generally that the source of titanium releases Ti atoms under high temperature of ultrasonic. Ti atoms react with aluminum to generate TiAl3, and react with carbon to generate TiC.

The influence of gadolinium on Al–Ti–C master alloy and its refining effect on AZ31 magnesium alloy

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Wenxue Fan ◽  
Hai Hao
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Grain Refinement ◽  
Magnesium Alloys ◽  
Master Alloy ◽  
Cast Alloy ◽  
Az31 Magnesium Alloy ◽  
Synthesis Mechanism ◽  
Refining Effect ◽  
Master Alloys

Abstract Grain refinement has a significant influence on the improvement of mechanical properties of magnesium alloys. In this study, a series of Al–Ti–C-xGd (x = 0, 1, 2, 3) master alloys as grain refiners were prepared by self-propagating high-temperature synthesis. The synthesis mechanism of the Al–Ti–C-xGd master alloy was analyzed. The effects of Al–Ti–C-xGd master alloys on the grain refinement and mechanical properties of AZ31 (Mg-3Al-1Zn-0.4Mn) magnesium alloys were investigated. The results show that the microstructure of the Al–Ti–C-xGd alloy contains α-Al, TiAl3, TiC and the core–shell structure TiAl3/Ti2Al20Gd. The refining effect of the prepared Al–Ti–C–Gd master alloy is obviously better than that of Al–Ti–C master alloy. The grain size of AZ31 magnesium alloy was reduced from 323 μm to 72 μm when adding 1 wt.% Al–Ti–C-2Gd master alloy. In the same condition, the ultimate tensile strength and elongation of as-cast alloy were increased from 130 MPa, 7.9% to 207 MPa, 16.6% respectively.

scholarly journals The Interactions Between Oxide Film Inclusions and Inoculation Particles TiB2 in Aluminum Melt

2021 ◽  
Author(s):  
Jiawei Yang ◽  
Sarina Bao ◽  
Shahid Akhtar ◽  
Yanjun Li
Keyword(s):  
Grain Refinement ◽  
Master Alloy ◽  
Large Fraction ◽  
Oxide Films ◽  
Grain Refiner ◽  
Particle Sedimentation ◽  
Aluminum Melt ◽  
Refinement Efficiency ◽  
Long Time ◽  
Commercial Purity Aluminum

AbstractIn this work, a systematic study on the interactions between aluminum oxide films and TiB2 grain refiner particles and their effect on grain refinement behavior have been conducted. Oxide films were introduced into a commercial purity aluminum melt by adding AA 6061 alloy chips while the grain refiner particles were introduced by adding Al-3T-1B master alloy. Strong sedimentation of TiB2 grain refiner particles was observed in aluminum melt without chip addition during long-time settling. Most of the TiB2 particles were settled and accumulated at the bottom of crucible. In contrast, the sedimentation of TiB2 particles is much less in the melt with the addition of oxide films. A large fraction of TiB2 particles were found to be adhered to the oxide films located at the top part of the crucible, which inhibited the sedimentation of grain refiner particles. TP-1 type tests were also done to study the grain refinement efficiency of Al-3Ti-1B master alloy under different melt cleanliness and settling time. It is found that sedimentation of TiB2 particles greatly reduces the grain refinement efficiency. The introduction of oxide films seems to slightly alleviate the fading effect. This is owing to the strong adherence between the oxide films and TiB2 particles, which leads to a retardation of particle sedimentation.

Preparation of Al-Ti-N Master Alloy Grain Refiner for Al

2012 ◽  
Vol 452-453 ◽  
pp. 721-725
Author(s):  
Z.Q. Wang ◽  
C.J. Chen
Keyword(s):  
Master Alloy ◽  
Grain Refiner

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.

The Research Progress of TiB2 Impacts on the Refining Effect of Al-Ti-B Master Alloy

2014 ◽  
Vol 574 ◽  
pp. 391-395
Author(s):  
Li Mi ◽  
Jun Jun Wang ◽  
Zhi Liu Hu
Keyword(s):  
Master Alloy ◽  
Refining Process ◽  
Research Progress ◽  
Grain Refining ◽  
Grain Refiner ◽  
Standing Time ◽  
Refining Effect ◽  
Initial Nucleus ◽  
Refinement Mechanism ◽  
The Impact

Al-Ti-B master alloy is the most widely used grain refiner in the aluminum fabrication industry, while it’s refinement mechanism is not clearly understand yet. The TiB2 in Al-Ti-B master alloy is one of important phase to grain refining, which intimately related to the generation of initial nucleus, the “fading” phenomenon of refining effect declines with the increase of holding or standing time in grain refining process. Besides, TiB2 is analyzed in several studies about the “poisoning” phenomenon, a large extent weaken of refining effect when Zr, Cr, Mn etc. exists. In this article, the impact of TiB2 to the refining effect of Al-Ti-B master alloy is discussed aiming at the roles and phenomenon mentions above.

Influence of a Novel Master Alloy Addition on the Grain Refinement of Al-Si Cast Alloys

2013 ◽  
Vol 765 ◽  
pp. 311-315 ◽  
Author(s):  
Leandro Bolzoni ◽  
Magdalena Nowak ◽  
N. Hari Babu
Keyword(s):  
Grain Refinement ◽  
Master Alloy ◽  
Intermetallic Phases ◽  
Al Alloys ◽  
Grain Structure ◽  
Grain Refiner ◽  
Casting Alloys ◽  
Alloy Addition ◽  
Cast Alloys ◽  
The Impact

The grain refinement practice using Ti based chemical additions is well established for wrought Al alloys, especially in the last few decades. In the case of Al-Si casting alloys the practice of adding grain refiners and the impact on castability is not well established in industries. The main reason is the chemical instability of conventionally known Ti based grain refiner which reacts with silicon forming intermetallic phases. Recently, researchers at Brunel University have identified a novel chemical composition that can refine the grain structure of Al-Si alloys in an effective way. Over the last year, this novel grain refiner in the form of master alloy was developed and tested in various Al-Si cast alloys that are commonly used in industry. Significant grain refinement is obtained when the master alloy is added to the liquid metal prior to casting. Moreover, the grain size of the Al-Si cast alloys is observed to be less sensitive to cooling rate when the master alloy is added. In this work, the influence of addition of the master alloy on microstructural evolution of various Al-Si alloys cast under various cooling rates is presented.

Effect of Grain Refiner on Microstructure of Semi-Solid A356 Aluminium Alloy

2014 ◽  
Vol 1024 ◽  
pp. 251-254 ◽  
Author(s):  
Mohd Nasir Laila Masrur ◽  
Anasyida Abu Seman ◽  
Hussain Zuhailawati
Keyword(s):  
Aluminium Alloy ◽  
Master Alloy ◽  
Optical Microscope ◽  
Grain Refining ◽  
Grain Refiner ◽  
Inclined Slope ◽  
Semi Solid ◽  
Vicker’S Microhardness ◽  
Steel Mould ◽  
A356 Aluminium Alloy

Grain refining has been studied in the semi-solid-metal (SSM) casting by addition of master alloy Al-5Ti-1B using inclined slope. A356 aluminium alloy was melted at 850 °C and poured at 660 °C on the inclined slope into the steel mould. Grain refiner was added in various percentages of 0.2%, 0.5% and 1.0% in A356 aluminium alloy melt. Microstructure and microhardness were characterized using optical microscope and Vicker’s microhardness tester. The addition of master alloy Al-5Ti-1B not only refined but also increased the globularity of the primary α-Al particles. The higher hardness was achieved with 1% addition of master alloy Al-5Ti-1B.

scholarly journals Effect of CeO2 Size on Microstructure, Synthesis Mechanism and Refining Performance of Al-Ti-C Alloy

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6739
Author(s):  
Yanli Ma ◽  
Taili Chen ◽  
Lumin Gou ◽  
Wanwu Ding
Keyword(s):  
Master Alloy ◽  
Pure Aluminum ◽  
Second Phase ◽  
Formation Temperature ◽  
Scanning Calorimetry ◽  
Synthesis Mechanism ◽  
Second Phase Particles ◽  
Master Alloys ◽  
Refining Performance ◽  
Commercial Pure Aluminum

The effects of CeO2 size on the microstructure and synthesis mechanism of Al-Ti-C alloy were investigated using a quenching experiment method. A scanning calorimetry experiment was used to investigate the synthesis mechanism of TiC, the aluminum melt in situ reaction was carried out to synthesize master alloys and its refining performance was estimated. The results show that the Al-Ti-C-Ce system is mainly composed of α-Al, Al3Ti, TiC and Ti2Al20Ce. The addition of CeO2 obviously speeds up the progress of the reaction, reduces the size of Al3Ti and TiC and lowers the formation temperature of second-phase particles. When the size of CeO2 is 2–4 μm, the promotion effect on the system is most obvious. The smaller the size of CeO2, the smaller the size of Al3Ti and TiC and the lower the formation temperature. Al-Ti-C-Ce master alloy has a significant refinement effect on commercial pure aluminum. When the CeO2 size is 2–4 μm, the grain size of commercial pure aluminum is refined to 227 μm by Al-Ti-C-Ce master alloy.

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