The overall solid-to-solid phase transformation kinetics under non-isothermal conditions has been modeled by means of a differential equation method. The method requires provisions for expressions of the fraction of the transformed phase in equilibrium condition and the relaxation time for transition as functions of temperature. The thermal history is an input to the model. We have used the method to calculate the time/temperature variation of the volume fraction of the favored phase in the alpha-to-beta transition in a zirconium alloy under heating and cooling, in agreement with experimental results. We also present a formulation that accounts for both additive and non-additive phase transformation processes. Moreover, a method based on the concept of path integral, which considers all the possible paths in thermal histories to reach the final state, is suggested.
Tailoring the magnetic properties of nanocrystalline Cu-Co alloys prepared by high-pressure torsion and isothermal annealing
在这项研究中，严重的塑性形变高压扭转被用来作为大量的纳米晶磁性CuCo合金的制造方法。通过随后的等温退火，可以获得过饱和固溶体的相分离。的磁性能的处理和退火的材料进行了系统的研究和相关的发展中的纳米结构的详细研究，通过透射电子显微镜和原子探针断层扫描。通过在液氮温度下进行额外的高压扭转变形，可以进一步调节Cu 74 Co 26合金的磁性能。
High isothermal magnetocaloric effect in La(Fe,Si)13 based alloys
Kotelnikov Institute of Radioengineering and Electronics of RAS（俄罗斯科学院科捷利尼科夫无线电电子学研究所）；Galkin Donetsk Institute for Physics and Technology（加爾金頓涅茨克物理技術研究所）；Amirkhanov Institute of Physics, Dagestan Federal Research Center of RAS（俄罗斯科学院达吉斯坦联邦研究中心阿米尔哈诺夫物理研究所）
A macroscale, phase-field model for shape memory alloys with non-isothermal effects: influence of strain-rate and environmental conditions on the mechanical response
In recent times,there has been a significant volume of work on Eutectic High Entropy Alloys (EHEAs) owing to their remarkable castability combined with excellent mechanical properties,which aids in clearing obstacles for their technological applications. One of the most common EHEAs,which has been of enormous interest at present, primarily owing to its solidification and tensile behavior, is AlCoCrFeNi$_{2.1}$. However,to aim for high-temperature applications,oxidation behaviour of material is one of the major aspects that needs to be extensively investigated.To this end,the present work aims …
Effect of ballistic re-solution on the nucleation kinetics of precipitates in diluted binary alloys under irradiation. Part 2: Cr-rich alpha' precipitates in Fe-Cr alloys
Nuclear Safety Institute (IBRAE), Russian Academy of Sciences（俄罗斯科学院核安全研究所（IBRAE））
Non-isothermal flow of Al-, Co- and Cu-based alloys made in different spatial configurations or structural states: model and experimental study
Derzhavin Tambov State University（德尔扎文坦波夫国立大学）；Lomonosov Moscow State University（莫斯科罗蒙诺索夫国立大学）；Northwestern Polytechnical University（西北工业大学）；Siberian State Industrial University（西伯利亚国立工业大学）；National University of Science and Technology «MISIS»（国立科技大学“MISIS”）
Effect of ballistic re-solution on the nucleation kinetics of precipitates in diluted binary alloys under irradiation. Part 1: Stoichiometric gamma' precipitates in Ni-Al alloys
Nuclear Safety Institute (IBRAE), Russian Academy of Sciences（俄罗斯科学院核安全研究所（IBRAE））
Diffusion of atoms in solids is one of the most fundamental kinetic processes that ultimately governs many materials properties. Here, we report on a combined first-principles and kinetic Monte Carlo study of macroscopic diffusion properties of disordered Ti-Ta alloys over the entire composition range. Using simple cluster expansion model Hamiltonians parametrized on density functional theory data, we compute transport properties explicitly including local interactions between the two atomic species and compare them with the non-interacting diffusion model for disordered, random alloys. Surpri…
Neutron irradiation tends to promote disorder in ordered alloys through the action of the thermal spikes that it generates, while simultaneously introducing point defects and defect clusters. As they migrate, these point defects will promote reordering of the alloys, acting against irradiation-induced disordering. In this study, classical molecular dynamics and a highly parallel accelerated sampling method are used to study the reordering kinetics of Ni$_3$Al under the diffusion of self-interstitial atoms (SIA). By monitoring the order parameter and potential energy from atomistic simulations,…
We present a kinetic model for solid state phase transformation (alpha<-->beta) of common zirconium alloys used as fuel cladding material in light water reactors. The model computes the relative amounts of beta or alpha phase fraction as a function of time or temperature in the alloys. The model accounts for the influence of excess oxygen (due to oxidation) and hydrogen concentration (due to hydrogen pickup) on phase transformation kinetics. Two variants of the model denoted by A and B are presented. Model A is suitable for simulation of laboratory experiments in which the heating/cooling rate…
Statistical Thermodynamics and Ordering Kinetics of D019-Type Phase: Application of the Models for H.C.P.-Ti-Al Alloy
采用自洽场近似、静态浓度波近似和Onsager型动力学方程，建立了D 019相原子有序化的统计热力学和动力学描述，并应用于h. c. p. - Ti-Al合金有序-无序相变模型描述了h. c. p.固溶体向D 019相的相变。原子间相互作用参数估计的两个近似：一个假设温度无关的原子间相互作用参数，而另一个包括温度依赖的Ti-Al合金的交换能。部分Ti-Al相图（共存的有序相和无序相的平衡成分）的评估为这两种情况。分析了D 019型长程序（LRO）参量的时间依赖关系。的曲线（显示的LRO参数的演变）数值得到的温度无关的相互作用能和温度相关的。原子间相互作用能的温度依赖性加速了LRO弛豫，并减小了瞬时和平衡LRO参数随温度变化的值的扩散。热力学-热力学和动力学结果表明，在高温下，非化学计量比（其中合金组分的原子分数大于0.25）的平衡LRO参数可以高于化学计量比。实验相图证实了h. c. p.的预测（有序或无序）状态。钛铝合金
Studies of concentration and temperature dependencies of precipitation kinetics in iron-copper alloys using kinetic monte carlo and stochastic statistical simulations
Dynamic Kinetic Evaluation Favors Compositionally Diverse Multicomponent Alloy Nanoparticles for Hydrogen Evolution
The University of Tokyo（东京大学）；National Institute for Materials Science（物质材料研究机构）；National Institute of Advanced Industrial Science and Technology（产业技术综合研究所）
The Kinetics of Primary Alpha Plate Growth in Titanium Alloys
通过比较模型与实验，检查了从β细胞生长的原代α-Ti菌落/魏氏平板的动力学。板生长速度敏感地依赖于速率限制物质的扩散系数D（T）和生长板周围的过饱和度。这些结果在一个最大的增长速度约40 K低于transus，一旦足够的过饱和度是可用于驱动板的生长。在Ti-6246中，发现板生长速度在850 oC时为约0.32 um min-1，这与模型预测的0.36 um min-1非常一致。生长板周围的溶质场，板的厚度，被发现是相当可变的，由于板和软碰撞的共生。发现该溶质场延伸至高达30 nm，并且发现β中的界面浓度约为6.4 at.%密苏里州发现增加O含量将对连续冷却期间预期的板长度具有最小的影响;相反，Mo每增加2 wt.钼还原。使用V代替Mo作为β稳定剂的合金预期在名义上相等的V含量下具有快得多的板生长动力学。这些发现将为合金和工艺路线的集成设计提供有用的工具，以实现定制的微观结构。
Ternary alloys of Ge-Sb-Te (GST) have been extensively studied due to their unique ability display a reversible change in their phase upon stimulation by optical pulses i.e., amorphous (a-GST) to crystalline (c-GST) and vice-versa. The two phases exhibit remarkably different electrical and optical properties like conductivity, reflectivity, refractive index and optical loss, this coupled with their high phase switching speeds, low power phase switching, large measurable optical and electrical contrast, and phase stability makes GST alloys stand out from other phase change materials (PCM). GST …
Although of practical importance, there is no established modeling framework to accurately predict high-temperature cyclic oxidation kinetics of multi-component alloys due to the inherent complexity. We present a data analytics approach to predict the oxidation rate constant of NiCr-based alloys as a function of composition and temperature with a highly consistent and well-curated experimental dataset. Two characteristic oxidation models, i.e., a simple parabolic law and a statistical cyclic-oxidation model, have been chosen to numerically represent the high-temperature oxidation kinetics of c…
