AMI: Acta Materialia最新文献_第5页

Stabilization of Compressed Earth Blocks (CEB) by Pozzolana Based Phosphate Geopolymer: Physico-Mechanical, Structural and Microstructural Investigations 磷酸酯磷酸酯地聚合物对压缩土块(CEB)的稳定性:物理力学、结构和微观结构研究

AMI: Acta Materialia Pub Date : 2021-01-01 DOI: 10.2139/ssrn.3855724

Tchouateu Kamwa Rolande Aurelie, Sylvain Tome, Chongouang Judicaёl, E. Idriss, A. Spieß, Markus N. A. Fetzer, K. Elie, C. Janiak, Marie-Annie Etoh

引用次数: 3

Deformation of Aluminum in Situ Sem and Full Field Measurements by Digital Image Correlation: Evidence of Concomitant Crystal Slip and Grain Boundary Sliding 铝的原位扫描电镜变形和数字图像相关的全场测量:伴随晶体滑移和晶界滑动的证据

AMI: Acta Materialia Pub Date : 2021-01-01 DOI: 10.2139/ssrn.3922862

A. Dimanov, A. El Sabbagh, J. Raphanel, T. Le, M. Bornert, S. Hallais, A. Tanguy

{"title":"Deformation of Aluminum in Situ Sem and Full Field Measurements by Digital Image Correlation: Evidence of Concomitant Crystal Slip and Grain Boundary Sliding","authors":"A. Dimanov, A. El Sabbagh, J. Raphanel, T. Le, M. Bornert, S. Hallais, A. Tanguy","doi":"10.2139/ssrn.3922862","DOIUrl":"https://doi.org/10.2139/ssrn.3922862","url":null,"abstract":"Mechanical testing in situ scanning electron microscopy (SEM) has become a current technique for multiscale micromechanical investigation of polycrystalline materials, because direct observation of deformation microstructures allows identification of strain heterogeneities and related mechanisms. Yet, most of the studies are based on the inherited post mortem microstructures, thus precluding to unravel the local loading history, to understand the development of localization patterns, the potential interactions of concomitant mechanisms and to quantify their respective contributions to the overall strain. We therefore developed a novel experimental setup for thermomechanical testing in situ SEM, especially suited for full strain field measurements based on digital image correlation (DIC) from the sample scale, to the scales of the aggregate and the single grain. We present results obtained during simple compression, at controlled displacement rate and at temperatures up to 400°C, for polycrystalline aluminum presenting randomly oriented coarse grains (ca. 300 μm in size). According to the different scales of interest, specific surface marking patterns were realized by electron microlithography. Kinematic analysis by digital image correlation (DIC) allowed to retrieve full surface strain fields. The latter evidenced that the overall viscoplastic response was dominated by crystal slip plasticity. Increasing temperature favored the activation of non-octahedral slip, but also substantial and continuous contribution of grain boundary sliding (GBS). We suggest the latter mechanism as necessary to accommodate local plastic incompatibilities between neighboring grains.","PeriodicalId":7755,"journal":{"name":"AMI: Acta Materialia","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85112375","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: 1

Measuring Radiation Enhanced Diffusion Through in situ Ion Radiation Induced Sintering of Oxide Nanoparticles 通过原位离子辐射诱导烧结氧化纳米颗粒测量辐射增强扩散

AMI: Acta Materialia Pub Date : 2021-01-01 DOI: 10.2139/ssrn.3951050

N. Madden, S. Briggs, Diana Perales, T. Boyle, K. Hattar, J. Krogstad

{"title":"Measuring Radiation Enhanced Diffusion Through in situ Ion Radiation Induced Sintering of Oxide Nanoparticles","authors":"N. Madden, S. Briggs, Diana Perales, T. Boyle, K. Hattar, J. Krogstad","doi":"10.2139/ssrn.3951050","DOIUrl":"https://doi.org/10.2139/ssrn.3951050","url":null,"abstract":"Radiation enhanced diffusion often contributes significantly to the evolution of microstructures subject to radiation but can be challenging to predict in complex nonmetallic material systems. Here, microstructural evolution in the presence of ion radiation was leveraged to explore the underlying transport phenomenon. Specifically, in situ ion irradiation of nanoparticles reveal rapid densification at room temperature for nanoparticles of cerium oxide (CeO2) and yttria stabilized zirconia (YSZ) but not for magnesium oxide (MgO) or silicon carbide (SiC). This is attributed to rapid diffusion of radiation induced interstitial defects to the high density of free surfaces in the nanoparticle agglomerates. When these observations are combined with image processing and application of a simple two-sphere sintering model, radiation enhanced diffusivity values can be calculated. In situ irradiation of YSZ nanoparticles over a broader temperature range, 50 K to 1073 K, clearly revealed a transition between three distinct rate limiting regimes: (i) low temperature, sink-limited kinetics, (ii) intermediate temperature, recombination-limited kinetics, and (iii) at high-temperature the densification is consistent with thermally activated diffusion kinetics. The high spatial and temporal resolution provided by the in situ methodology is critical to confidently distinguishing these regimes in nonmetallic oxides. While only four nonmetallic nanoparticle systems are presented here (YSZ, CeO2, SiC, and MgO), application of this methodology to the readily accessible, diverse catalog of nanoparticle chemistries and morphologies will allow for rapid exploration of radiation-enhanced diffusion behavior in a broader range of complex nonmetallic systems without the need for tracers.","PeriodicalId":7755,"journal":{"name":"AMI: Acta Materialia","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79451513","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: 1

The Role of Β-Zr in Zr-2.5nb Alloys During Aqueous Corrosion: A Multi-Technique Study Β-Zr在Zr-2.5nb合金水溶液腐蚀中的作用:多技术研究

AMI: Acta Materialia Pub Date : 2021-01-01 DOI: 10.2139/ssrn.3779737

Junliang Liu, G. He, A. Callow, Kexue Li, K. Moore, H. Nordin, Michael Moody, S. Lozano-Perez, C. Grovenor

{"title":"The Role of Β-Zr in Zr-2.5nb Alloys During Aqueous Corrosion: A Multi-Technique Study","authors":"Junliang Liu, G. He, A. Callow, Kexue Li, K. Moore, H. Nordin, Michael Moody, S. Lozano-Perez, C. Grovenor","doi":"10.2139/ssrn.3779737","DOIUrl":"https://doi.org/10.2139/ssrn.3779737","url":null,"abstract":"Zr–2.5Nb alloy are used as pressure tubes in Canadian Deuterium Uranium (CANDU) nuclear reactors, and the typical starting microstructure consists of α-Zr grains elongated in both transverse and longitudinal directions and thin layers of partly decomposed β-Zr lying between the α-Zr grains. In this study, we have used state-of-the-art microscopy techniques to characterise the long-term thermally decomposed β phase in these alloys, and the oxide scale formed on them in a reactor coolant loop with the aim of understanding the mechanisms underpinning the thermal decomposition behaviour at service temperatures and exploring the role of the decomposed β-Zr phase in controlling the microstructure and microchemistry of the zirconium oxide, and hence its influence on the general corrosion resistance of the alloy. We observe that these β-Zr layers are heavily decomposed even after the short stress stage at 400°C at the end of the manufacturing cycle, with a closely packed array of β-Nb precipitates forming in an α-Zr matrix. We have shown that the oxidation of these bands is significantly slower than the surrounding α-Zr matrix and that zirconium oxide grains are re-nucleated under each band. We conclude that it is the combination of the Nb-rich remnants of the original β-Zr layers arising from the hot extrusion and drawing stages and this new dense oxide that offers a significant barrier to the oxidation front (and also to the penetration of hydrogenic species), so the characteristic layered microstructure arising from the original manufacturing process is very important in determining the overall oxidation behaviour.","PeriodicalId":7755,"journal":{"name":"AMI: Acta Materialia","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88390470","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

Nanoporous Carbon From Mulberry Leaves Residues via Microwave Assisted Hydrothermal-Carbonization for Methyl Orange Adsorption: Kinetic, Equilibrium and Thermodynamic Studies 微波辅助水热碳化桑叶残基纳米孔碳吸附甲基橙:动力学、平衡和热力学研究

AMI: Acta Materialia Pub Date : 2021-01-01 DOI: 10.2139/ssrn.3906849

Siwat Siraoranroj, N. Kaewtrakulchai, M. Fuji, A. Eiad-ua

{"title":"Nanoporous Carbon From Mulberry Leaves Residues via Microwave Assisted Hydrothermal-Carbonization for Methyl Orange Adsorption: Kinetic, Equilibrium and Thermodynamic Studies","authors":"Siwat Siraoranroj, N. Kaewtrakulchai, M. Fuji, A. Eiad-ua","doi":"10.2139/ssrn.3906849","DOIUrl":"https://doi.org/10.2139/ssrn.3906849","url":null,"abstract":"High performance nanoporous carbons (MLC) were directly prepared from mulberry leaves (Morus alba L.) residues by the hydrothermal-carbonization with chemical reagent combined the microwave-assisted treatment. The as-purified MLC was successfully applied for the adsorption of methyl orange, which is one of crucial waste-water pollutants left from an industrial sector. The MLC sample obtained from the hydrothermal process (200 °C, 12 h) using an activation of 15 wt% NaOH (700 °C, 2 h), and combined with microwave treatment at 700 W for 6 min, specifically exhibited micropores and mesopores in the MLC morphological structure. Accordingly, the highest SBET was approximately 791.79 m2/g with the total pore volume of 0.495 cm3/g. Moreover, the adsorption performance test of MLC was conducted by the shaking unit using 100 ppm methyl orange concentration. The MLC showed the highest methyl orange-adsorption uptake of 99% at 30 °C under an ambient pressure (1 atm). The development of mulberry leaves (Morus alba L.) residues into MLC exhibited a great attention for dyes adsorption with a rapid adsorption kinetic, and excellent adsorption capacity, which are a promising-characteristics for practical waste-water adsorption experiments.","PeriodicalId":7755,"journal":{"name":"AMI: Acta Materialia","volume":"70 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90655643","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

Study of Microbands in a Fe-30mn-6.5al-0.3c Low-Density Steel Deformed at Cryogenic Temperature Fe-30mn-6.5al-0.3c低温变形低密度钢的微带研究

AMI: Acta Materialia Pub Date : 2021-01-01 DOI: 10.2139/ssrn.3947689

I. Gutierrez-Urrutia, A. Shibata, K. Tsuzaki

{"title":"Study of Microbands in a Fe-30mn-6.5al-0.3c Low-Density Steel Deformed at Cryogenic Temperature","authors":"I. Gutierrez-Urrutia, A. Shibata, K. Tsuzaki","doi":"10.2139/ssrn.3947689","DOIUrl":"https://doi.org/10.2139/ssrn.3947689","url":null,"abstract":"The microband (MB) formation mechanisms in an austenitic Fe-30Mn-6.5Al-0.3C (wt.%) low-density steel tensile deformed at -196°C were investigated by combined electron channeling contrast imaging (ECCI) and electron backscatter diffraction (EBSD). The grain orientation dependences of the MB structure, MB morphology, and MB alignment were quantitatively evaluated in grains oriented with the two main texture components, namely, <111>//tensile axis (TA) and <001>//TA. The interplay between the deformation structure and MB formation was analyzed. Our analysis indicates that the underlying deformation structure controls the MB formation mechanism and, at the current deformation conditions, also determines the crystallographic character of MBs. Most of the evaluated MBs have a crystallographic character (deviation angle <5° from {111} slip plane traces). Specifically, 77% of the MBs in the grains oriented close to <111>//TA directions and all the MBs evaluated in grains oriented close to <001>//TA directions have a crystallographic character. They are associated with a planar strain localization phenomenon occurring along highly-stressed crystallographic slip planes. Non-crystallographic MBs (deviation angle >5° from {111} slip plane traces) only occur in the grains oriented close to <111>//TA directions. They are associated with the splitting of pre-existing dense-dislocation walls (DDWs). At high strain levels, we foresee the activation of a GB-assisted MB formation mechanism associated with twin-GB interactions.","PeriodicalId":7755,"journal":{"name":"AMI: Acta Materialia","volume":"1012 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77174468","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

Effect of Aging State on Fatigue Property of Wrought Aluminum Alloys 时效状态对变形铝合金疲劳性能的影响

AMI: Acta Materialia Pub Date : 2021-01-01 DOI: 10.2139/ssrn.3919744

B. Gong, Z.J. Zhang, Z. Qu, J. Hou, H.J. Yang, X. Shao, Z. Zhang

引用次数: 8

Low-Fatigue and Large Room-Temperature Elastocaloric Effect in a Bulk Ti 49.2Ni 40.8Cu 10 Alloy Ti 49.2Ni 40.8Cu 10块状合金的低疲劳大室温弹性热效应

AMI: Acta Materialia Pub Date : 2021-01-01 DOI: 10.2139/ssrn.3927821

Pengfei Dang, Yumei Zhou, Lei Ding, J. Pang, Lei Zhang, X. Ding, Jun Sun, T. Lookman, D. Xue

引用次数: 2

Solubility Limit and Annealing Effects on the Microstructure & Thermoelectricproperties of Fe 2V 1-XTa xAl 1-YSi y Heusler Compounds fe2v 1-XTa xAl 1-YSi y Heusler化合物的溶解度极限和退火对其微观结构和热电性能的影响

AMI: Acta Materialia Pub Date : 2021-01-01 DOI: 10.2139/ssrn.3762208

F. Garmroudi, M. Parzer, A. Riss, N. Reumann, B. Hinterleitner, K. Tobita, Y. Katsura, K. Kimura, T. Mori, E. Bauer

{"title":"Solubility Limit and Annealing Effects on the Microstructure & Thermoelectricproperties of Fe 2V 1-XTa xAl 1-YSi y Heusler Compounds","authors":"F. Garmroudi, M. Parzer, A. Riss, N. Reumann, B. Hinterleitner, K. Tobita, Y. Katsura, K. Kimura, T. Mori, E. Bauer","doi":"10.2139/ssrn.3762208","DOIUrl":"https://doi.org/10.2139/ssrn.3762208","url":null,"abstract":"Full-Heusler compounds with the composition Fe2V1-XTaxAl1-YSiy have recently shown to exhibit some of thehighest power factors reported so far for bulk materials due to the band convergence and band gap opening causedby the V/Ta substitution. Therefore, the solubility limit of Ta and Si regarding the stability of the L21 phase isinvestigated in this study. The crystal structure and microstructure of a large number of samples is probed by X-raydiffraction as well as scanning electron microscopy and energy dispersive X-ray analysis. The results show that the Al/Si substitution significantly hampers the solubility of Ta within the Heusler structure. Furthermore, Fe2V0.9Ta0.1Al and Fe2V0.95Ta0.05Al0.9Si0.1 reveal nanoscale impurity precipitates in the microstructure, together with diffuse contrasts that indicate a non-equilibrium metastable state. For that reason, different annealing conditions, varying the temperature and time, have been applied to the latter and the effect on the microstructure and thermoelectric properties is investigated. It is found that additional annealing leads to further phase segregation and grain growth of the impurity precipitates, which due to their metallic-like nature have a detrimental effect on the Seebeck coefficient. They can however effectively reduce the lattice thermal conductivity if the average grain size remains below the phonon mean free path. The thermoelectric efficiency in terms of the dimensionless gure of merit ZT is increased up to ZT = 0.3 - 0.34 at 300K which is beyond the values previously reported for Fe2VAl-based bulk materials.","PeriodicalId":7755,"journal":{"name":"AMI: Acta Materialia","volume":"103 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90309739","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: 1

High-Quality A1GaN Epitaxy on Lattice-Engineerable AlN Template for High-Power UVC Light-Emitting Diodes 在高功率UVC发光二极管的栅格工程AlN模板上的高质量A1GaN外延

AMI: Acta Materialia Pub Date : 2021-01-01 DOI: 10.2139/ssrn.3946395

S. Walde, Cheng-Yao Huang, Chia-Lung Tsai, Wen-Hsuang Hsieh, Yi-Keng Fu, S. Hagedorn, Cheng-Yao Huang, T. Lu, M. Weyers, Chia-Yen Huang

{"title":"High-Quality A1GaN Epitaxy on Lattice-Engineerable AlN Template for High-Power UVC Light-Emitting Diodes","authors":"S. Walde, Cheng-Yao Huang, Chia-Lung Tsai, Wen-Hsuang Hsieh, Yi-Keng Fu, S. Hagedorn, Cheng-Yao Huang, T. Lu, M. Weyers, Chia-Yen Huang","doi":"10.2139/ssrn.3946395","DOIUrl":"https://doi.org/10.2139/ssrn.3946395","url":null,"abstract":"AlGaN-based UVC light-emitting diodes (LED) were fabricated on high-quality AlN templates with an engineerable in-plane lattice constant. The controllability of the in-plane strain originated from the vacancy formation in Si-doped AlN (AlN:Si) and their interaction with edge dislocations. The strain state of the AlN:Si top interface could be well depicted by a dislocation-tilt model depending on the buffer strain state, threading dislocation density (TDD), and regrown AlN:Si thickness. The validity of the model was verified by cross-sectional TEM analysis. With a gradually widened lattice constant of regrown AlN:Si layer, strain-induced defects of subsequently grown n-AlGaN was suppressed. Therefore, growing a current spreading layer which possesses a moderate Al content (<65%), decent thickness (>1.5 μm), and a low TDD (<1.0×10 9 cm -2 ) simultaneously becomes possible. Additionally, the idea of an optimal edge TDD ) in the AlN buffer was revealed for growing high-quality n-AlGaN layers with a targeted thickness. After a deliberate strain-TDD engineering for AlN:Si and n-AlGaN, high-power UVC LEDs (P>200 mW) with a low forward voltage (V f =5.7 volt) were demonstrated at I=1.35 A. The low forward voltage under high current injection density was attributed to the success in preparation of a low series resistance and high-quality n-AlGaN current spreading layer.","PeriodicalId":7755,"journal":{"name":"AMI: Acta Materialia","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88398814","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