scholarly journals Features of Al-10Mo electron-beam produced master-alloy assimilation in liquid aluminum and AlSi9Cu3 alloy

2021 ◽  
Vol 99 (3) ◽  
pp. 49-56
Author(s):  
M. M. Voron ◽  
◽  
M. A. Fon Pruss ◽  
Keyword(s):  
Electron Beam ◽  
Uniform Distribution ◽  
Master Alloy ◽  
Pure Aluminum ◽  
Liquid Aluminum ◽  
Cost Effective ◽  
High Dispersion ◽  
Resource Saving ◽  
Master Alloys ◽  
Short Time

The work is devoted to the Al-10Mo electron-beam prepared master-alloy modifying phases dissolution and assimilation features determination. It is shown that the obtained master-alloy is characterized by uniform distribution and high dispersion of molybdenum aluminide particles. When studying the process of dissolving the master-alloy in pure aluminum, it was determined that the time of modification of the melt more than 20 minutes at a temperature of 740 ± 10 ° C leads to the most complete destruction of the original intermetallics Al22Mo5 and Al17Mo4 and the formation of smaller and evenly distributed particles Al5Mo and Al12Mo with dimensions about 2 μm. As the molybdenum content decreases, the dispersion of the modifying phases and the uniformity of their distribution increase. Increasing the temperature and exposure time do not improve the assimilation of the modifier. The Al-10Mo master-alloy, obtained in the conditions of electron-beam casting technology, has a number of characteristics that allow to consider it as more efficient and cost-effective, compared to known analogues. This is due to the much higher concentration of molybdenum in the modifier (10% wt.), as well as fine dispersion and uniform distribution of the modifying phases. The nonequilibrium composition of aluminides inherent in the ligatures obtained under these conditions contributes to their significant grinding and refining after addition into aluminum melts. The stoichiometry of the phases from Al22Mo5 and Al17Mo4 changes to Al12Mo, which serve as crystallization centers and have a size of about 1 μm, dissolves and changes. The example of industrial casting alloy AlSi9Cu3 shows complete and effective assimilation of the master-alloy in a short time of 5 minutes at a temperature of 740 ± 10 ° C. Such indicators are more economic, in comparison with standard industrial ones, for which both higher temperature of melt preparing ant longer lifetime in liquid state after modification are necessary. Keywords: master-alloys, Al-Mo, modifications, aluminum alloys, AlSi9Cu3, resource saving.

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.

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 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.

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.

The Grain Refinement of Al-Si Alloys and the Cause of Si Poisoning: Insights Revealed by the Interdependence Model

2014 ◽  
Vol 794-796 ◽  
pp. 161-166 ◽  
Author(s):  
Mark A. Easton ◽  
Arvind Prasad ◽  
David H. St. John
Keyword(s):  
Grain Size ◽  
Grain Refinement ◽  
Master Alloy ◽  
Cost Effective ◽  
Optimum Level ◽  
Grain Sizes ◽  
Relative Contribution ◽  
Master Alloys ◽  
Effective Use ◽  
Special Case

Recent work has extended the Interdependence Model to the prediction of grain size of aluminium alloys when refined by Al-Ti-B master alloys. The relative contribution of Ti solute and TiB2 particles to the as-cast grain size was determined indicating the optimum level of addition required to provide cost effective use of master alloy. This paper quantifies the effect of Al5Ti1B master alloy additions on the grain size of Al-Si alloys. The Al-Si system is a special case where additions of Si above a few percent poison grain refinement resulting in larger grain sizes. Consideration of the complicating effect of Si poisoning on the prediction of the grain size of these alloys and possible approaches to dealing with these complications are presented.

Techniques for Transmission Electron Microscopy of Fiber-Matrix Interfaces in Aluminum Alloy-Boron Composites by Ion Erosio

1971 ◽  
Vol 29 ◽  
pp. 204-205
Author(s):  
G. G. Shaw
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Aluminum Alloy ◽  
Electron Beam ◽  
Pure Aluminum ◽  
Ion Milling ◽  
Transmission Electron ◽  
Fiber Matrix ◽  
Ion Erosion ◽  
Row Of Fibers

The morphology and composition of the fiber-matrix interface can best be studied by transmission electron microscopy and electron diffraction. For some composites satisfactory samples can be prepared by electropolishing. For others such as aluminum alloy-boron composites ion erosion is necessary.When one wishes to examine a specimen with the electron beam perpendicular to the fiber, preparation is as follows: A 1/8 in. disk is cut from the sample with a cylindrical tool by spark machining. Thin slices, 5 mils thick, containing one row of fibers, are then, spark-machined from the disk. After spark machining, the slice is carefully polished with diamond paste until the row of fibers is exposed on each side, as shown in Figure 1.In the case where examination is desired with the electron beam parallel to the fiber, preparation is as follows: Experimental composites are usually 50 mils or less in thickness so an auxiliary holder is necessary during ion milling and for easy transfer to the electron microscope. This holder is pure aluminum sheet, 3 mils thick.

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 Environmental Engineering Techniques to Restore Degraded Posidonia oceanica Meadows

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 661
Author(s):  
Luigi Piazzi ◽  
Stefano Acunto ◽  
Francesca Frau ◽  
Fabrizio Atzori ◽  
Maria Francesca Cinti ◽  
...  
Keyword(s):  
Large Scale ◽  
Natural Habitat ◽  
Cost Benefit ◽  
Cost Effective ◽  
Posidonia Oceanica ◽  
Environmental Engineering ◽  
Bottom Surface ◽  
Sessile Invertebrates ◽  
Set Up ◽  
Short Time

Seagrass planting techniques have shown to be an effective tool for restoring degraded meadows and ecosystem function. In the Mediterranean Sea, most restoration efforts have been addressed to the endemic seagrass Posidonia oceanica, but cost-benefit analyses have shown unpromising results. This study aimed at evaluating the effectiveness of environmental engineering techniques generally employed in terrestrial systems to restore the P. oceanica meadows: two different restoration efforts were considered, either exploring non-degradable mats or, for the first time, degradable mats. Both of them provided encouraging results, as the loss of transplanting plots was null or very low and the survival of cuttings stabilized to about 50%. Data collected are to be considered positive as the survived cuttings are enough to allow the future spread of the patches. The utilized techniques provided a cost-effective restoration tool likely affordable for large-scale projects, as the methods allowed to set up a wide bottom surface to restore in a relatively short time without any particular expensive device. Moreover, the mats, comparing with other anchoring methods, enhanced the colonization of other organisms such as macroalgae and sessile invertebrates, contributing to generate a natural habitat.

scholarly journals Feasibility Study of the Cranial Implant Fabricated without Supports in Electron Beam Melting

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 496
Author(s):  
Khaja Moiduddin ◽  
Syed Hammad Mian ◽  
Wadea Ameen ◽  
Hisham Alkhalefah ◽  
Abdul Sayeed
Keyword(s):  
Electron Beam ◽  
Electron Beam Melting ◽  
Structural Characteristics ◽  
Cost Effective ◽  
Medical Industry ◽  
Detailed Review ◽  
Build Time ◽  
Cranial Implant ◽  
Cranial Implants ◽  
Fabrication Time

Additive manufacturing (AM), particularly electron beam melting (EBM), is becoming increasingly common in the medical industry because of its remarkable benefits. The application of personalized titanium alloy implants produced using EBM has received considerable attention in recent times due to their simplicity and efficacy. However, these tailored implants are not cost-effective, placing a tremendous strain on the patient. The use of additional materials as support during the manufacturing process is one of the key causes of its high cost. A lot of research has been done to lessen the use of supports through various types of support designs. There is indeed a noticeable paucity of studies in the literature that have examined customized implants produced without or minimal supports. This research, therefore, reports on the investigation of cranial implants fabricated with and without supports. The two personalized implants are evaluated in terms of their cost, fabrication time, and accuracy. The study showed impressive results for cranial implants manufactured without supports that cost 39% less than the implants with supports. Similarly, the implant’s (without supports) build time was 18% less than its equivalent with supports. The two implants also demonstrated similar fitting accuracy with 0.2613 mm error in the instance of implant built without supports and 0.2544 mm for the implant with supports. The results indicate that cranial implants can be produced without EBM supports, which can minimize both production time and cost substantially. However, the manufacture of other complex implants without supports needs further study. The future study also requires a detailed review of the mechanical and structural characteristics of cranial implants built without supports.

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