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.

The Effects of Rare Earth Element on the Al-Ti-B Master Alloy Second Phase

2014 ◽  
Vol 574 ◽  
pp. 380-385
Author(s):  
Hua Hu ◽  
Zhi Liu Hu ◽  
Liang Jie Wei ◽  
Jian Bao Yin
Keyword(s):  
Rare Earth ◽  
Rare Earth Element ◽  
Master Alloy ◽  
Mass Fraction ◽  
Earth Element ◽  
Intermediate Phase ◽  
Second Phase ◽  
Second Phase Particles ◽  
Master Alloys

Al-Ti-B-RE master alloy is an efficient long-term new refiner. Al-Ti-B-RE refiner was prepared by Al-Ti-B master alloy doped with LaF3, La-rich RE carbonate and Ce respectively. This paper studies the effect of different type and mass fraction of RE on the Second Phase Particles distributions and shape in Master Alloys. The addition of RE have a certain effect of refining TiAl3 and TiB2 intermediate phase. Moreover, it prevents aggregation of TiB2 intermediate phase. As the different type and addition of RE has an effect on the microstructure of master alloy, then the reasonable addition of RE is put forward.

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.

Research on a New Type Grain Refiner Refining α-Al by Adding Molten State and Diluted Al-Ti-B-RE Master Alloy

2012 ◽  
Vol 535-537 ◽  
pp. 915-918
Author(s):  
Zheng Jun Wang
Keyword(s):  
Master Alloy ◽  
Second Phase ◽  
Grain Refining ◽  
X Ray Diffraction ◽  
Grain Refiner ◽  
X Ray ◽  
Second Phase Particles ◽  
Refining Performance ◽  
New Type ◽  
The Cost

Al-Ti-B-RE master alloy was prepared by casting of pure Ti. To improve the quality and reduce the cost of α- Al, the Al-Ti-B-RE master alloy was added to α-Al in molten and diluted state. The refining method had the advantages of shorter contact time and better refining effect. The array of the second phase particles was separated and the nucleating rate was greatly increased. Analysis and comparison of the refining effects were by X-ray diffraction (XRD), scanning electron microscopy (SEM) and optical microscopy (OM).The refining experiment showed that the molten and diluted state Al-Ti-B-RE by oneself had better grain refining performance and had obvious advantages over Al-Ti-B in domestic.

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.

The Combined Effect of Modifier and Grain Refiner AlTiBSr Master Alloy on Microstructure and Porosity of Aluminum Alloys

2006 ◽  
Vol 526 ◽  
pp. 223-228 ◽  
Author(s):  
Petru Moldovan ◽  
Gabriela Popescu ◽  
Marilena Cuhutencu
Keyword(s):  
Electron Microscopy ◽  
Aluminum Alloys ◽  
Master Alloy ◽  
Aluminum Industry ◽  
New Combination ◽  
Grain Refining ◽  
Grain Refiner ◽  
Multifunctional Material ◽  
Master Alloys ◽  
Foundry Alloys

The aim of the paper is to present the influence of a new multifunctional material, a master alloy named Al-Sr-Ti-B, in aluminum foundry alloys. The Al-Sr-Ti-B master alloy represents a new combination of two master alloys, already known in aluminum industry, AlTiB and AlSr, used in treatment of aluminum alloys for grain refining and modification. As Strobloy, our master alloy contain fast dissolving SrAl4 particles and also nucleating particles as TiB2 and (Al,Ti)B2 which are important first in modification and second in grain refining of aluminum alloys. The paper presents optic and electron microscopy studies realized on AlSi7Mg alloy treated with this new multifunctional material

Grain Refinement Mechanism and Effective Nucleation Phase of Al-5Ti-1B Master Alloy

2017 ◽  
Vol 898 ◽  
pp. 1231-1235 ◽  
Author(s):  
Shun Cheng Wang ◽  
Ji Lin Li ◽  
Chun Lei Gan ◽  
Kai Hong Zheng
Keyword(s):  
Grain Size ◽  
Grain Refinement ◽  
Master Alloy ◽  
Pure Aluminum ◽  
Grain Refiner ◽  
Crystal Nucleus ◽  
Master Alloys ◽  
Refinement Mechanism ◽  
Nucleation Phase ◽  
Heterogeneous Nucleus

The Al-5Ti-1B, Al-10Ti, Al-4B master alloys and TiB2 powder were applied to refine the pure aluminum, respectively. The effects of the TiAl3 phase, TiB2 particle, and AlB2 phase on the grain size of pure aluminum were compared. The grain refinement mechanism of the Al-5Ti-1B grain refiner was studied. The results showed that the TiAl3 phase was an effective heterogeneous nucleus of the α-Al grain. But the TiAl3 phase in the Al-5Ti-1B grain refiner was not the heterogeneous nucleus of the α-Al grain due to its re-melting in the Al melt. The separate TiB2 particle or AlB2 phase was not the heterogeneous nucleus of the α-Al grain. However, the TiB2 coated by the TiAl3 phase can be the effective heterogeneous nucleus of the α-Al grain. The grain refinement mechanism of the Al-5Ti-1B grain refiner can be summarized as follows: when the Al-5Ti-1B grain refiner is added into the Al melt, the TiAl3 phases are re-melted to release the Ti atoms, while the TiB2 particles are remaining in the Al melt. During the solidification of the Al melt, the Ti atoms are segregating on the surface of TiB2 particles to form the TiAl3 phases. The TiB2 particles coated by the TiAl3 phases then reacts with the Al melt to generate α-Al crystal nucleus.

scholarly journals Grain Refinement of AZ91 Magnesium Alloy Induced by Al-V-B Master Alloy

Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1333 ◽  
Author(s):  
Wang Chang ◽  
Yanping Shen ◽  
Yueying Su ◽  
Long Zhao ◽  
Yunhu Zhang ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Comparative Study ◽  
Grain Refinement ◽  
Master Alloy ◽  
Al Alloys ◽  
Az91 Alloy ◽  
Grain Refiner ◽  
Az91 Magnesium Alloy ◽  
Master Alloys ◽  
Az91 Magnesium

It has long been recognized that grain refinement of Mg-Al alloys is difficult, although various methods have been tried. In the present paper, a novel grain refiner, Al-3.4V-1B master alloy, has been developed to refine the as-cast AZ91 alloy. A comparative study on grain refinement effects of Al-3.4V-1B, Al-5V, and Al-3Ti-1B master alloys was performed under the same solidification conditions. It is shown that Al-3.4V-1B master alloy not only has significant grain refinement ability, but also keeps stable anti-fading capacity with holding time up to 2 h. Based on the analysis of grain refinement, VB2 particles introduced by Al-3.4V-1B master alloy are the heterogeneous nuclei for AZ91 alloy.

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.

Grain Refinement in Titanium-Erbium Alloys

1974 ◽  
Vol 32 ◽  
pp. 522-523
Author(s):  
B. B. Rath ◽  
J. E. O'Neal ◽  
R. J. Lederich
Keyword(s):  
Electron Microscopy ◽  
Size Distribution ◽  
Grain Refinement ◽  
Grain Growth ◽  
Volume Fraction ◽  
Pure Titanium ◽  
Systematic Investigation ◽  
Second Phase ◽  
Titanium Matrix ◽  
Average Size

Addition of small amounts of erbium has a profound effect on recrystallization and grain growth in titanium. Erbium, because of its negligible solubility in titanium, precipitates in the titanium matrix as a finely dispersed second phase. The presence of this phase, depending on its average size, distribution, and volume fraction in titanium, strongly inhibits the migration of grain boundaries during recrystallization and grain growth, and thus produces ultimate grains of sub-micrometer dimensions. A systematic investigation has been conducted to study the isothermal grain growth in electrolytically pure titanium and titanium-erbium alloys (Er concentration ranging from 0-0.3 at.%) over the temperature range of 450 to 850°C by electron microscopy.

Polishing process effect on the image of dispersed precipitates

1984 ◽  
Vol 42 ◽  
pp. 534-535
Author(s):  
C.T. Hu ◽  
C.W. Allen
Keyword(s):  
Matrix Material ◽  
Specimen Preparation ◽  
Second Phase ◽  
Precipitate Particle ◽  
Polishing Process ◽  
Second Phase Particles ◽  
The Matrix ◽  
Surface Profiles ◽  
Thinning Process

One important problem in determination of precipitate particle size is the effect of preferential thinning during TEM specimen preparation. Figure 1a schematically represents the original polydispersed Ni3Al precipitates in the Ni rich matrix. The three possible type surface profiles of TEM specimens, which result after electrolytic thinning process are illustrated in Figure 1b. c. & d. These various surface profiles could be produced by using different polishing electrolytes and conditions (i.e. temperature and electric current). The matrix-preferential-etching process causes the matrix material to be attacked much more rapidly than the second phase particles. Figure 1b indicated the result. The nonpreferential and precipitate-preferential-etching results are shown in Figures 1c and 1d respectively.

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