The grain refinement potency of bismuth in magnesium

Joshi, Utsavi; Babu, N. Hari

doi:10.1016/j.jallcom.2016.10.215

Cited by 19 publications

(9 citation statements)

References 20 publications

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“…Therefore, by increasing Zr content from 0.25 to 0.9 wt%, grain size takes a decreasing trend. It is worth mentioning that Zr has the highest growth restriction factor (GRF) among all Mg alloying elements …”

Section: Resultsmentioning

confidence: 99%

“…It is worth mentioning that Zr has the highest growth restriction factor (GRF) among all Mg alloying elements. [19] Figure 2 shows OM images of the AZ63 alloy containing various amounts of Be indicating the higher the Be content, the coarser the microstructure. [20] The proposed mechanism of grain coarsening effect of Be is acting Be as an active surfactant.…”

Section: Microstructure Characterizationmentioning

confidence: 99%

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Influence of Zr and Be on microstructure and electrochemical behavior of AZ63 anode

Jafari

Hassanizadeh

2018

Materials & Corrosion

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In this study, the effect of Zr and Be on the microstructure and electrochemical properties of a common magnesium alloy anode, AZ63, used in cathodic protection, was investigated. The AZ63, as well as Zr (0.25, 0.50, 0.70, and 0.90 wt%) and Be (0.0001, 0.001, 0.01, and 0.1 wt%) bearing AZ63 anodes, were prepared. The microstructure and electrochemical characteristics of the cast anodes were characterized. The results showed that the addition of Zr refines the grain size of the AZ63 anode; and above 0.5 wt% Zr, forms Al2Zr and β‐Mg17Al12. In contrast, grain coarsening was observed with increasing Be content. Moreover, the addition of 0.1 wt% Be to the anode resulted in the spheroidization of the β‐phase. Also, it was shown that AZ63‐0.5 wt% Zr provides the lowest corrosion rate among the experimented anodes, and the higher the Be content, the lower the corrosion rate of the anode. Higher content of both Be and Zr alloying elements resulted in improved efficiency of the anode for 20% and 13%, respectively. The results of this study indicate higher impact of Be on the efficiency increment of the AZ63 anode.

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Section: Resultsmentioning

confidence: 99%

Section: Microstructure Characterizationmentioning

confidence: 99%

Influence of Zr and Be on microstructure and electrochemical behavior of AZ63 anode

Jafari

Hassanizadeh

2018

Materials & Corrosion

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“…The strategic workflow for the alloy design approach driven by computational thermodynamics is shown in Figure 2. As demonstrated in the figure, computational thermodynamics based on a reliable thermodynamic database and software/code can provide accurate predictions of different factors determining the castability [81][82][83][84][85][86] , cracking tendency [87][88][89][90] , grain refinement [91][92][93] , microstructure modification [94][95][96][97] , and basic physical properties [98][99][100][101] of casting aluminum alloys, from which the alloy composition [95] , heat treatment mechanisms [102] and even manufacturing means [102] can be optimized, e.g., by using multi-objective design strategy.…”

Section: Computational Thermodynamics Technique and Its Applicationsmentioning

confidence: 99%

“…Moreover, when the solute diffusion in liquid is rate-controlling, the presence of solutes leads to growth restriction. The growth restriction factor (Q-value) has frequently been used to analyze and control grain refinement during the solidification of aluminum alloys [91][92][93] . It has been demonstrated that the Q-value in multicomponent alloys can be predicted from nonequilibrium solidification simulation results based on reliable thermodynamic descriptions/databases [111][112][113][114][115] .…”

Section: Grain Refinementmentioning

confidence: 99%

Boosting for concept design of casting aluminum alloys driven by combining computational thermodynamics and machine learning techniques

Wang¹,

Liu²,

Gao³

et al. 2021

JMI

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Casting aluminum alloys are commonly used in industries due to their excellent comprehensive performance. Alloying/microalloying and post-solidification heat treatments are the most common measures to tune the microstructure for enhancing their mechanical properties. However, it is very challenging to achieve accurate and efficient development of novel casting aluminum alloys using the traditional trial-and-error method. With the rapid development of computer technology, the computational thermodynamics (CT) in the framework of the CALculation of PHAse Diagram approach, the data-driven machine learning (ML) technique, and also their combinations have been proved to be effective approaches for the design of casting aluminum alloys. In this review, the state-of-the-art computational alloy design approaches driven by CT and ML techniques, as well as their combinations, were comprehensively summarized. The current status of the thermodynamic database for aluminum alloys, as the core for CT, was also briefly introduced. After that, a variety of successful case studies on the design of different casting aluminum alloys driven by CT, ML, and their combinations were demonstrated, including common applications, CT-driven design of Sc-additional Al-Si-Mg series casting alloys, and design of Srmodified A356 alloys driven by combing CT and ML. Finally, the conclusions of this review were drawn, and perspectives for boosting the computational design approach driven by combining CT and ML techniques were pointed out.

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“…Grain refinement is a practical method to improve the mechanical properties of magnesium alloys, and relevant research demonstrates that inoculation is an effective method of melt treatment to achieve grain refinement. [ 1–5 ] Thus, the development of efficient and reliable refiners for Mg alloys is technologically important and necessary. According to the crystallographic perspective‐based edge‐to‐edge matching model, Zhang and co‐workers predicted and explained a series of currently available grain refiners for Al and Mg alloys.…”

Section: Introductionmentioning

confidence: 99%

The Refinement Effect of Alumina–Silica Sol‐Coated ZnO Particles for Cast Magnesium

Cao

Meng

2020

Adv Eng Mater

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Grain refinement is a practical method to improve the mechanical properties of magnesium alloys, and relevant research demonstrates that inoculation is an effective method of melt treatment to achieve grain refinement. [1-5] Thus, the development of efficient and reliable refiners for Mg alloys is technologically important and necessary. According to the crystallographic perspective-based edge-to-edge matching model, Zhang and co-workers predicted and explained a series of currently available grain refiners for Al and Mg alloys. [2,6,7] Combining the crystallographic database and edge-to-edge matching model calculation, a series of potential grain refiners for Mg alloys have been predicted, such as Al 2 Ca, AlN, Al 2 Y, CaO, AlMn, and ZnO, and experimental results match well with the theoretical predictions. [8-14] Based on edge-to-edge crystallographic matching calculation, ZnO is predicted to be one of the most effective candidates for Mg refinement, as it has an hexagonal close-packed (HCP) structure and belongs to the P63mc space group. The lattice parameters of ZnO are a ¼ 0.3265 nm and c ¼ 0.5219 nm, which are very close to those of the Mg matrix, i.e., a ¼ 0.320936 nm, and c ¼ 0.521123 nm. This prediction was based on the lattice parameters of ZnO and Mg at room temperature, which are expected to vary slightly at higher temperatures. However, some previous work showed that a small variation in lattice parameters between room temperature and solidification temperature does not affect the refining results. [15-17] Therefore, based on the success of previous applications of the edge-to-edge crystallographic matching model to the crystallographic understanding of grain refinement, these small misfits suggest that ZnO is likely to be an efficient grain refiner for Mg alloys. This prediction has been supported by preliminary results from other researchers. [18,19] However, according to thermodynamic data, ZnO particle reduction in molten Mg could occur as follows [7] MgðlÞ þ ZnOðsÞ ! MgOðsÞ þ ZnðlÞ ΔG θ 1000 ¼ À236.7 kJ mol À1 (1) ZnO would be reduced into Zn solute in contact with molten Mg, which would damage the crystallographic structure of the ZnO particles, affecting its use as a refiner for Mg. As the separation of inclusion and casting processes usually takes time, it is difficult to completely prevent the reduction between ZnO and Mg. At the same time, a reduction that generates Zn solute and native MgO could also lead to grain refinement for Mg alloys. [20] Although there is a reduction reaction between the added ZnO particles and molten Mg, the grain refinement achieved by ZnO particles is still better than that achieved with the equivalent addition of pure Zn. Saha and Ravindran and Ohtomo et al. suggested that ZnO acts as a heterogeneous nucleation before the ZnO particle is totally reduced to Zn solute by the molten Mg. [21,22] However, the refinement effect of ZnO on Mg may still be compromised because of the reduction reaction. Alumina and silica sol have been applied to fabricate protective coat...

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The grain refinement potency of bismuth in magnesium

Cited by 19 publications

References 20 publications

Influence of Zr and Be on microstructure and electrochemical behavior of AZ63 anode

Influence of Zr and Be on microstructure and electrochemical behavior of AZ63 anode

Boosting for concept design of casting aluminum alloys driven by combining computational thermodynamics and machine learning techniques

The Refinement Effect of Alumina–Silica Sol‐Coated ZnO Particles for Cast Magnesium

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