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Machine Learning Techniques in Predicting Hot Deformation Behavior of Metallic Materials

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computer Modeling in Engineering & sciences 2025年第1期142卷 713-732页

作者： Petr Opela Josef Walek Jaromír kopecek Department of Metallurgical Technologies Faculty of Materials Science and TechnologyVSB–Technical University of OstravaOstrava70800Czech Republic FZU—Institute of Physics of the czech Academy of sciences Prague18200Czech Republic

In engineering practice,it is often necessary to determine functional relationships between dependent and independent *** relationships can be highly nonlinear,and classical regression approaches cannot always provide sufficiently reliable ***,Machine Learning(ML)techniques,which offer advanced regression tools to address complicated engineering issues,have been developed and widely *** study investigates the selected ML techniques to evaluate their suitability for application in the hot deformation behavior of metallic *** ML-based regression methods of Artificial Neural Networks(ANNs),support Vector Machine(sVM),Decision Tree regression(DTr),and Gaussian Process regression(GPr)are applied to mathematically describe hot flow stress curve datasets acquired experimentally for a medium-carbon *** the GPr method has not been used for such a regression task before,the results showed that its performance is the most favorable and practically unrivaled;neither the ANN method nor the other studied ML techniques provide such precise results of the solved regression analysis.

关键词： Machine learning Gaussian process regression artificial neural networks support vector machine hot deformation behavior

Assessment of sensitization in AIsI 304 stainless steel by Nonlinear Ultrasonic Method

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Acta Metallurgica sinica(English Letters) 2013年第5期26卷 545-552页

作者： saju T.Abraham s.k.Albert c.r.Das N.Parvathavarthini B.Venkatraman r.s.Mini k.Balasubramaniam Quality Assurance Division Indira Gandhi Centre for Atomic Research Department of Mechanical Engineering Government Engineering College Department of Mechanical Engineering Indian Institute of Technology

A nonlinear ultrasonic technique has been developed to evaluate sensitization in Type 304 stainless steel. In order to achieve diferent degree of sensitization（DOs）, specimens have been subjected to heat treatment at 675℃ at varying soaking time（0.5, 1.0, 2.0, 3.0 and 4.0 h）. Heat treated specimens were subjected to intergranular corrosion tests as per AsTM standards A262 and G108. sensitization in longer soaked material has been confirmed through ditch microstructures, cracks on the bend tested specimens and higher degree of sensitization. Nonlinear ultrasonic studies showed variation in the nonlinearity parameter with soaking time which also confirms sensitization. A good correlation was observed between the degree of sensitization measured by the electrochemical potentiokinetic reactivation test and the ultrasonic nonlinearity *** study clearly demonstrated that nonlinear ultrasonic technique can be used as a potential technique for non-destructive characterization of sensitization in austenitic stainless steel.

关键词： Austenitic stainless steel Degree of sensitization Intergranular corrosion Nonlinear ultrasonics

regression analysis of squeezing-induced hybrid nanofluid flow in Darcy-Forchheimer porous medium

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 193-208页

作者： k.MUHAMMAD M.sArFrAZ Department of Humanities and sciences School of Electrical Engineering and Computer Science National University of Sciences and Technology Department of Mathematics Quaid-i-Azam University

This article presents a mathematical model addressing a scenario involving a hybrid nanofluid flow between two infinite parallel plates. One plate remains stationary, while the other moves downward at a squeezing velocity. The space between these plates contains a Darcy-Forchheimer porous medium. A mixture of water-based fluid with gold(Au) and silicon dioxide(si O2) nanoparticles is formulated. In contrast to the conventional Fourier's heat flux equation, this study employs the cattaneo-christov heat flux equation. A uniform magnetic field is applied perpendicular to the flow direction, invoking magnetohydrodynamic(MHD) effects. Further, the model accounts for Joule heating, which is the heat generated when an electric current passes through the fluid. The problem is solved via NDsolve in MATHEMATIcA. Numerical and statistical analyses are conducted to provide insights into the behavior of the nanomaterials between the parallel plates with respect to the flow, energy transport, and skin *** findings of this study have potential applications in enhancing cooling systems and optimizing thermal management strategies. It is observed that the squeezing motion generates additional pressure gradients within the fluid, which enhances the flow rate but reduces the frictional drag. consequently, the fluid is pushed more vigorously between the plates, increasing the flow velocity. As the fluid experiences higher flow rates due to the increased squeezing effect, it spends less time in the region between the plates. The thermal relaxation, however, abruptly changes the temperature, leading to a decrease in the temperature fluctuations.

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cryptic species composition and genetic diversity within Bemisia tabaci complex in soybean in India revealed by mtcOI DNA sequence

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Journal of Integrative Agriculture 2015年第9期14卷 1786-1795页

作者： Prasanna H c kanakala s Archana k Jyothsna P Varma r k Malathi V G Division of Vegetable Improvement Indian Institute of Vegetable Research Advanced centre for Plant Virology Division of Plant PathologyIndian Agricultural Research Institute Department of Plant Pathology Jawaharlal Nehru Krishi Vishwavidyalaya

Bemisia tabaci is a cryptic species complex, causing signiifcant loss on many agricultural y important crops worldwide. knowledge on species composition and diversity within B. tabaci complex is critical for evolving sustainable pest management strategies. Here we investigate the whitelfy species complex in soybean in major soybean growing states of India. The mitochondrial cytochrome oxidase gene subunit-1 (mtcOI) based phylogenetic relationships established using Bayesian methods indicated the existence of three cryptic species namely Asia I, Asia II 1, and Asia II 7. Al the haplotypes detected in the study could be assigned to these three cryptic species fol owing the species demarcation criteria of 3.5%divergence threshold. Of these, Asia II 1 was found to be predominant with wide spread distribution across the surveyed regions from cool temperate zones to hot and humid tropical plains. On the contrary, cryptic species Asia II 7 showed localized distribu-tion. The Asia II 1 exhibited the highest haplotype diversity and Asia I showed high level of nucleotide diversity. There was a signiifcantly high genetic differentiation among these three cryptic species. The MEAM 1, a dreadful invasive species was not detected in the specimens tested in the current study. The diversity and distribution of three cryptic species is discussed in the light of current knowledge on distribution of whitelfy species in India and yel ow mosaic disease observed during sampling survey.

关键词： whitefly mitochondrial cytochrome oxidase gene subunit-1 AsiaⅠ AsiaⅡ 1 AsiaⅡ 7 begomovirus and yellow mosaic disease

Property enhancement of cast iron used for nuclear casks

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International Journal of Minerals,Metallurgy and Materials 2016年第1期23卷 40-48页

作者： r.k. Behera B.P. Mahto J.s. Dubey s.c. Mishra s. sen Department of Metallurgical and Materials Engineering National Institute of Technology Rourkela Odisha 769008 India Bhaba Atomic research centre (Post Irradiation Examination Division) Mumbai 400085 India

Ductile iron （DI） is a preferred material for use in various structural, automotive, and engineering fields because of its excellent combination of strength, toughness, and ductility. In the current investigation, we elucidate the relationship between the morphological and mechanical properties of DI intended for use in safety applications in the nuclear industry. DI specimens with various alloying elements were subjected to annealing and austempering heat treatment processes. A faster cooling rate appeared to increase the nodule count in austempered specimens, compensating for their nodularity value and subsequently decreasing their ductility and impact strength. The ductility and impact energy values of annealed specimens increased with increasing ferrite area fraction and nodularity, whereas an increase in the amounts of Ni and cr resulted in an increase of hardness via solid solution strengthening. Austempered specimens were observed to be stronger than an- nealed specimens and failed in a somewhat brittle manner characterized by a river pattern, whereas the ductile failure mode was character- ized by the presence of dimples.

关键词： ductile iron nodularity mechanical properties failure modes nuclear industry

Zinc-oxide/PDMs-clad tapered fiber saturable absorber for passively mode-locked erbium-doped fiber laser

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chinese Physics B 2021年第5期30卷 384-389页

作者： F D Muhammad s A s Husin E k Ng k Y Lau c A c Abdullah M A Mahdi Department of Physics Faculty of ScienceUniversiti Putra Malaysia43400 UPM SerdangSelangorMalaysia Wireless and Photonics Networks research centre Faculty of EngineeringUniversiti Putra Malaysia43400 UPM SerdangSelangorMalaysia Department of Electronics and Nanoengineering Tietotie 3Aalto University02150 EspooFinland

We propose and demonstrate a passively mode-locked erbium-doped fiber laser(EDFL)based on zinc-oxide/polydimethylsiloxane(ZnO/PDMs)saturable absorber(sA)that evanescently interacts with the light on a tapered *** ZnO/PDMs composite is coated on the whole surface of the tapered fiber to guarantee the maximum efficiency of the sA device,with a measured insertion loss of 0.87 dB and a modulation depth of 6.4%.The proposed laser can generate soliton mode-locking operation at a threshold power of 33.07 *** generated output pulse yields a repetition rate and pulse width of 9.77 MHz and 1.03 ps,*** results indicate that the proposed ZnO/PDMs-clad tapered fiber could be useful as an efficient,compatible,and low-cost sA device for ultrafast laser applications.

关键词： zinc-oxide saturable absorber tapered fiber mode-locked fiber laser

The myth of “minima” and “maxima”,the species of Physalis in the Indian subcontinent

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植物分类学报 2007年第2期45卷 239-245页

作者： Vatsavaya s rAJU c s rEDDY k G rAJArAO Department of Botany Kakatiya UniversityWarangal 506009 India Forestry & Ecology Division National Remote Sensing AgencyHyderabad 500008 India Department of Botany Andhra UniversityWaltair 530003 India

The status of the names, Physalis minima L. and P. maxima Mill. (solanaceae), and their alleged presence on the Indian subcontinent are discussed. The issues of nativity and identity of Linnaean Physalis minima are long-debated while the use of the name P. maxima Mill. and its report from India are recent. The available evidence indicates that the name "P. minima L." is misapplied to two different elements, viz., P. angulata L. and P. lagascae roem. & schult. The name Physalis minima L. may be rejected as nomen confusum, for which the paper provides the primary information. As on today, it is submerged under the synonymy of P. angulata L. The correct name for the widely known P. minima is P. lagascae. The name "P. maxima Mill." applied to the escape and naturalized weed in the Indian subcontinent and elsewhere is to be substituted by P. pruinosa L., a name misapplied to P. grisea (Waterf.) M. Martínez.

关键词：酸浆属植物酸浆值植物分类植物命名

Age-hardening behavior,corrosion mechanisms,and passive film structure of nanocrystalline Al-V supersaturated solid solution

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Journal of Materials science & Technology 2023年第4期135卷 1-12页

作者： J.christudasjustus M.r.Felde c.s.Witharamage J.Esquivel A.A.Darwish c.Winkler r.k.Gupta Department of Materials science and Engineering North Carolina State UniversityRaleighNC 27606United States Department of chemical Biomolecular and Corrosion EngineeringThe University of AkronAkronOH 44325United States

The effect of age-hardening on microstructure,hardness,and corrosion of an Al-5at.%V alloy,produced us-ing high-energy ball milling and subsequent cold compaction,has been *** alloy exhibited a grain size below 100 nm and extremely high solid solubility of V in Al(3.1 at.%).The age-hardening was carried out at 150,200,and 250℃.The peak-aged condition of 150℃ demonstrated the highest hardness-transpired from grain refinement,precipitation,and solid solution *** corrosion re-sistance of the Al-5at.%V alloy was studied as a function of aging *** peak-aged condition retained the corrosion resistance while it deteriorated in the over-aged ***,the cor-rosion resistance of the ball-milled Al alloys in all the aging conditions was superior to that of pure *** passive film structure and origin of corrosion were studied using scanning/transmission electron mi-croscopy(s/TEM).The high corrosion resistance of the alloy was attributed to the V enrichment at the film/metal interface and deposition of V on the cathodic phases,which suppresses the dissolution of Al within the pit and therefore promotes repassivation in the early stages of corrosion.

关键词： Al alloys Nanocrystalline alloy Age-hardening Ball milling corrosion Hardness

Hydromagnetic unsteady slip stagnation flow of nanofluid with suspension of mixed bio-convection

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Propulsion and Power research 2019年第4期8卷 362-372页

作者： r.kumar s.sood c.s.k.raju s.A.shehzad Department of Mathematics Central University of Himachal PardeshDharamshala176215India Department of Mathematics GITAM UniversityBangalore562163KarnatakaIndia Department of Mathematics COMSATS Institute of Information TechnologySahiwal57000Pakistan

In this paper,stagnation point region(suspended with nanofluid and microorganisms)is examined subjected to velocity and thermal *** flow is assumed to be flowing across an exponentially stretching flat surface under magnetic field *** transport equations(framed under Buongiorno’s model)are converted into self-similar form through suitable unsteady exponential similarity transformations which are then solved by employing implicit finite difference scheme(IFDs)known as keller-box method(kBM).A parametric analysis is performed along with limited details of *** of pertinent constraints on local skin friction,local Nusselt number,local sherwood number and local density number of micro-organisms are also uncovered through graphs.A significant decrease in skin-friction coefficients has been detected with respect to thermal slip in comparison to velocity slip.

关键词： Unsteady flow stagnation point region Mixed convection Microorganisms Nanoparticles slip regime keller-box scheme