EngRN: Metals & Alloys (Topic)最新文献_第2页

A Study of the Effects of Amorphous/Crystalline Oxide Films on the Cold Spray Behavior of 6061 Al Alloy Powders 非晶/结晶氧化膜对6061铝合金粉末冷喷涂性能影响的研究

EngRN: Metals & Alloys (Topic) Pub Date : 2021-03-26 DOI: 10.2139/ssrn.3813431

A. Navabi, M. Vandadi, T. Bond, V. Rahneshin, J. D. Obayemi, R. Ahmed, J. Oghenevweta, N. Rahbar, V. Champagne, W. Soboyejo

{"title":"A Study of the Effects of Amorphous/Crystalline Oxide Films on the Cold Spray Behavior of 6061 Al Alloy Powders","authors":"A. Navabi, M. Vandadi, T. Bond, V. Rahneshin, J. D. Obayemi, R. Ahmed, J. Oghenevweta, N. Rahbar, V. Champagne, W. Soboyejo","doi":"10.2139/ssrn.3813431","DOIUrl":"https://doi.org/10.2139/ssrn.3813431","url":null,"abstract":"This paper presents the effects of nanoscale surface oxide layers on the cold spray behavior of 6061 Al alloy powders. The surface oxide films are revealed via Transmission Electron Microscopy (TEM), and Energy Dispersive X-ray Spectroscopy (EDS). Phenomena associated with surface contacts, contact-induced elastic-plastic deformation, heating, and cracking are then simulated using a combination of analytical models, finite element analysis and Molecular Dynamics (MD) simulations. MD simulations are used to provide insights into the effects of powder impact on deformation and fracture at powder impact velocities that are consistent with previously reported critical velocities and predictions. MD simulations are also used to obtain estimates of oxide film moduli, toughness, strains to failure, and the fracture energies of aluminum oxide films with crystalline and amorphous structures. These are incorporated into finite element simulations of cold spray contact-induced deformation and cracking. The impact between the powder particles with nanoscale oxide layer and the substrate is modeled using a bi-linear Johnson-Cook model. The powder impacts are shown to result in localized splat deformation and heating, and the cracking of the oxide layers in ways that can expose fresh metallic surfaces to high temperature contacts (above the recrystallization temperature) that can give rise to bonding and mechanical interlocking. The implications of the results are discussed for the design of cold spray processes for the fabrication and repair of 6061 Al structures.","PeriodicalId":438337,"journal":{"name":"EngRN: Metals & Alloys (Topic)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115801431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Bi-Continuous Porous Structures from the Selective Dissolution of Ionic Solid Solutions 离子固体溶液选择性溶解的双连续多孔结构

EngRN: Metals & Alloys (Topic) Pub Date : 2021-02-21 DOI: 10.2139/ssrn.3790080

Diwen Xiao, Y. Ke, Congcheng Wang, Chunyong He, Qing Chen

引用次数: 2

Optimization of Powder Bed Fusion of Maraging Steel Powders for Plastic Injection Moulding 注射成型用马氏体时效钢粉末床熔合工艺的优化

EngRN: Metals & Alloys (Topic) Pub Date : 2021-02-15 DOI: 10.2139/ssrn.3785873

V. Vicario, D. Miceli

引用次数: 0

On Vacancy and Solute Co-Segregated η1 Interface in Over-Aged Al-Zn-Mg Alloys 过时效Al-Zn-Mg合金中空位和溶质共偏析η - 1界面的研究

EngRN: Metals & Alloys (Topic) Pub Date : 2020-12-31 DOI: 10.2139/ssrn.3757761

Y. Ou, Yong-zheng Jiang, Yiren Wang, Zhengqing Liu, A. Lervik, R. Holmestad

引用次数: 3

Revealing the Mechanisms for the Nucleation and Formation of Equiaxed Grains in Commercial Purity Aluminum by Fluid-Solid Coupling Induced by a Pulsed Magnetic Field 揭示脉冲磁场诱导的流固耦合作用下工业纯铝等轴晶形核形成机制

EngRN: Metals & Alloys (Topic) Pub Date : 2020-11-20 DOI: 10.2139/ssrn.3734066

J. Jie, S. Yue, J. Liu, D. StJohn, Y. Zhang, E. Guo, T. Wang, T.J. Li

{"title":"Revealing the Mechanisms for the Nucleation and Formation of Equiaxed Grains in Commercial Purity Aluminum by Fluid-Solid Coupling Induced by a Pulsed Magnetic Field","authors":"J. Jie, S. Yue, J. Liu, D. StJohn, Y. Zhang, E. Guo, T. Wang, T.J. Li","doi":"10.2139/ssrn.3734066","DOIUrl":"https://doi.org/10.2139/ssrn.3734066","url":null,"abstract":"This study considers the factors controlling the grain structure of commercially pure aluminium when a Pulsed Magnetic Field (PMF) is applied during solidification. It is revealed that PMF of pure metal forms equiaxed grains by two different nucleation and growth mechanisms depending on the casting conditions. One mechanism is nucleation of the columnar grains that grow into a shell on the walls of the mold before PMF is applied and once applied fluid-solid coupling develops due to the Lorenz force. Depending on the shell thickness, this fluid-solid coupling detaches the columnar shell or, for thicker shells, only the top few millimeters of the shell from the mold wall. The detached shell is then fragmented into large blocky grains due to a lower melting point iron-rich liquid phase on the grain boundaries. The other mechanism occurs on the mold wall when PMF is applied from above the melting point or on the exposed mold wall after detachment of the initially formed solidified shell as in the case above. In these conditions copious nucleation occurs on the mold wall and these fine grains are detached by pulses occurring every few milliseconds creating a bimodal structure of refined grains between the much fewer large blocky grains. The optimal condition for uniform refinement is when PMF is applied from above the melting point ensuring that a refined equiaxed grain structure forms throughout the casting.","PeriodicalId":438337,"journal":{"name":"EngRN: Metals & Alloys (Topic)","volume":"143 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122676442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 20

Contribution of Grain Boundary Misorientation to Intragranular Globular Austenite Reversion and Resultant in Grain Refinement in a High-Strength Low-Alloy Steel 高强度低合金钢晶界取向偏差对晶内球状奥氏体逆转的影响及其导致的晶粒细化

EngRN: Metals & Alloys (Topic) Pub Date : 2020-11-01 DOI: 10.2139/ssrn.3538765

X.L. Wang, Z. Wang, A. Huang, J.L. Wang, X. Li, S. Subramanian, C. Shang, Z. Xie

{"title":"Contribution of Grain Boundary Misorientation to Intragranular Globular Austenite Reversion and Resultant in Grain Refinement in a High-Strength Low-Alloy Steel","authors":"X.L. Wang, Z. Wang, A. Huang, J.L. Wang, X. Li, S. Subramanian, C. Shang, Z. Xie","doi":"10.2139/ssrn.3538765","DOIUrl":"https://doi.org/10.2139/ssrn.3538765","url":null,"abstract":"Abstract This paper elucidates the determining role of grain boundary types/misorientations on formation of intragranular globular austenite, which has random orientation or large deviation from the parent austenite, in a high-strength low-alloy bainitic steel during reaustenitization. Results revealed that within the parent austenite with lath bainite, reverted austenite with random orientation or large deviation from the parent austenite can nucleate at the packet and block boundaries with high misorientations, and rapidly evolve to become globular austenite with increase of temperature, making a significant contribution in final austenite grain refinement. While in granular bainite, the low misoriented boundaries belonging to the same Bain group are the preferred nucleation sites for the reverted austenite, which is detrimental to the formation of intragranular globular austenite. In addition, the precipitation mode of cementite is different in the reverse process, that is, cementite is precipitated from the matrix of lath bainite, but it is precipitated from retained austenite or martensite/austenite (M/A) particles in granular bainite, which will also lead to the different or consistent variant orientation of reverted austenite and matrix. Therefore, the final austenite grain refinement in initial granular bainite was mainly due to the formation of intergranular globular reverted austenite, and the refining effect is much lower than that of lath bainite.","PeriodicalId":438337,"journal":{"name":"EngRN: Metals & Alloys (Topic)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114979252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 10

Diffraction Artefacts from Twins and Stacking Faults, and the Mirage of Hexagonal, Polytypes or Other Supersuperstructures 孪晶和层错的衍射伪影，以及六边形、多型或其他超超结构的幻影

EngRN: Metals & Alloys (Topic) Pub Date : 2020-10-19 DOI: 10.2139/ssrn.3714494

C. Cayron

引用次数: 0

Phase Evolution in Two-Phase Alloys During Severe Plastic Deformation 两相合金在剧烈塑性变形过程中的相演化

EngRN: Metals & Alloys (Topic) Pub Date : 2020-10-12 DOI: 10.2139/ssrn.3708690

N. Pant, N. Verma, Y. Ashkenazy, P. Bellon, R. Averback

{"title":"Phase Evolution in Two-Phase Alloys During Severe Plastic Deformation","authors":"N. Pant, N. Verma, Y. Ashkenazy, P. Bellon, R. Averback","doi":"10.2139/ssrn.3708690","DOIUrl":"https://doi.org/10.2139/ssrn.3708690","url":null,"abstract":"Abstract Phase evolution in FCC metals with strongly interacting alloy components during severe plastic deformation is investigated using molecular dynamics simulations. Specifically, we study the alloy microstructure in steady state, nucleation and growth of precipitates in supersaturated alloys, and the dissolution of precipitates in undersaturated alloys. The results are compared to a modified effective temperature model, providing a physical understanding for the atomic processes underlying the model and a perspective on its strengths and weaknesses. Key observations in this work are nucleation and growth of precipitates during SPD at a temperature of 100 K; Gibbs-Thomson-like behavior relating steady-state solubility to precipitate size under sustained shearing; a direct relationship between the effective temperature and the shear modulus; and the importance of cluster agglomeration during precipitate growth. The study also reveals that the mechanism of forced chemical mixing depends on precipitate size, adding complications for effective temperature models describing inhomogeneous systems. The simulations are shown to provide good semi-quantitative agreement with experimental findings reported in the literature.","PeriodicalId":438337,"journal":{"name":"EngRN: Metals & Alloys (Topic)","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126066654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 8

Integrated Modeling of Helium-Vacancy Clustering in Eurofer97 Steel Upon He+/Fe3+ Dual Ion Beam Irradiation He+/Fe3+双离子束辐照下Eurofer97钢中氦-空位团簇的集成建模

EngRN: Metals & Alloys (Topic) Pub Date : 2020-10-05 DOI: 10.2139/ssrn.3692028

Jie Gao, E. Gaganidze, B. Kaiser, J. Aktaa

引用次数: 0

Atomistic Study of Grain-Boundary Segregation and Grain-Boundary Diffusion in Al-Mg Alloys Al-Mg合金晶界偏析和晶界扩散的原子学研究

EngRN: Metals & Alloys (Topic) Pub Date : 2020-08-14 DOI: 10.2139/ssrn.3683502

Raj Kiran Koju, Y. Mishin

引用次数: 60