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Characterization of FeCr and FeCoCr alloy coatings of carbon steels for marine environment applications

Applied Adhesion science 2013年第1期1卷 1-10页

作者： Antunes, Fernando José de Sá Brito, Vinícius Ribeiro dos Santos Bastos, Ivan Napoleão Costa, Hector Reynaldo Meneses Centro Federal de Educação Tecnológica Celso Suckow da Fonseca Graduate Program in Mechanical Engineering and Materials Technology Av. Maracanã 229 Rio de Janeiro RJ – 20271-110 Brazil Universidade do Estado do Rio de Janeiro Graduate Program in Materials Science and Technology Rua Bonfim 25 Nova Friburgo RJ – 28625-570 Brazil

This paper presents the adhesive strength results of FeCr and FeCoCr deposits produced by electric arc thermal spray process on carbon steel plates. Five chemical compositions were tested to give a large panel of possibility. Coatings were characterized by several methods to result in a performance screening. The main assessment of microstructural morphology was made by scanning electron microscopy (SEM). The mechanical strength of coatings was evaluated by standard pull-off test. The corrosion resistance was analyzed in salt-spray test. The morphology of coatings exhibits characteristics of lamellar microstructures with incompletely melted particles together with a distribution of similarly oriented oxides. The adhesive strength of FeCoCr alloy coatings was higher amongst all studied conditions. All sealed conditions presented low corrosion in salt-spray exposure. Additionally, a new FeCoCr alloy was studied to reduce pores and microcracks that are frequently found in traditional FeCr and FeCrNi alloys. Based on the performed characterizations, the findings suggested that the FeCoCr deposition, with an epoxy sealing, is suitable to be used as an efficient coating of carbon steel in aggressive marine environments. © 2013, Antunes et al.;licensee Springer.

关键词： Adhesion test Carbon steel FeCoCr coating Salt-spray test Thermal spray

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Influence of Al-5.0Nb-0.5B inoculant on the microstructure and mechanical properties of AA 2017 alloy fabricated using laser-based powder bed fusion

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Journal of Alloys and Compounds 2025年 1032卷

作者： Pamela Karina dos Santos Bomfim Bruna Fernanda Batistão Aylanna Priscila Marques de Araújo Leandro Henrique Pereira Ricardo Henrique Buzolin Sergio T. Amancio-Filho Conrado Ramos Moreira Afonso Claudemiro Bolfarini Claudio Shyinti Kiminami Francisco Gil Coury Piter Gargarella Graduate Program in Materials Science and Engineering Federal University of São Carlos Rod.Washington Luis Km 235 São Carlos SP 13565-905 Brazil High Performance and Lightweight Materials Group kopernikusgasse 24 Graz 8010 Austria BMK Endowed Professorship for Aviation Kopernikusgasse 24 Graz 8010 Austria Institute of Materials Science Joining and Forming Graz University of Technology Kopernikugasse 24/l Graz 80210 Austria Department of Materials Engineering (DEMa) Federal University of São Carlos (UFSCar) Rod. Washington Luiz km 235 São Carlos 13565-905 Brazil Center of Characterization and Development of Materials Federal University of São Carlos Rod. Washington Luiz km 235 SP-310 São Carlos SP 13565-905 Brazil

This study investigated the influence of the inoculant Al-5.0Nb-0.5B on the microstructure and mechanical properties of the AA 2017 alloy fabricated using laser-based powder bed fusion (L-PBF). The AA 2017 alloy powder was obtained through gas atomization and then mixed with 2 wt% of Al-5.0Nb-0.5B powder (20–53 µm) and synthesized using the L-PBF technique. The small addition of the Al-5.0Nb-0.5B, coupled with specific processing parameters, led to a reduction in the fraction of cracks and transformed the solidification structure from cellular to equiaxial. Additionally, it resulted in a grain size reduction down to 4.0 ± 2.9 µm and a low fiber texture. Due to the refined grains, the AA 2017 samples with 2 wt% Al-5.0Nb-0.5B exhibited a high yield strength of 215 ± 33 MPa and ultimate compressive strength of 602 ± 47 MPa, compared to the AA 2017 alloy samples, which exhibited yield strength of 171 ± 8 MPa and ultimate compressive strength of 427 ± 46 MPa. The addition of a small fraction of Al-5.0Nb-0.5B to the AA 2017 alloy, produced by L-PBF, is a promising alternative for manufacturing lightweight parts with a lower amount of hot cracks and equiaxial microstructure. The results show that the use of inoculant with the micrometric size is an effective alternative to the use of nanoparticles, which has a higher safety risk, is usually difficult to homogenize and may promote agglomeration.

关键词： Compressive strength

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Role of delamination fracture for enhanced impact toughness in 0.05 %P doped high strength steel with ultrafine elongated grain structure

Role of delamination fracture for enhanced impact toughness ...

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7th International Conference on Processing and Manufacturing of Advanced materials, THERMEC'2011

作者： Jafari, Meysam Kimura, Yuuji Tsuzaki, Kaneaki Doctoral Program in Materials Science and Engineering Graduate School of Pure and Applied Science University of Tsukuba 1-2-1 Sengen Tsukuba Ibaraki 305-0047 Japan Structural Metals Center National Institute for Materials Science 1-2-1 Sengen Tsukuba Ibaraki 305-0047 Japan

ISBN: (纸本)9783037853047

Ultrafine elongated grain (UFEG) structures with strong 〈110〉// rolling direction (RD) fiber deformation texture were produced by warm caliber-rolling at 773 K, namely tempforming in the 1200 MPa-class medium-carbon low-alloy steel with phosphorous (P) contents of 0.001 and 0.053 mass%. Charpy impact tests were performed at temperature range of -196 to 150 °C on the UFEG structure. Regardless of P content, high upper shelf energy about 145 J and a very low ductile to brittle transition temperature (DBTT) of around -175 °C were obtained. P segregation embrittlement completely disappeared in the 0.053 %P steel and both steels showed ductile fracture on the planes normal to RD at temperature range of -150 to 150 °C. The main reason for the high upper shelf energy and very low DBTT in the 0.053 %P steel would be delamination fracture along RD when both 0.001 and 0.053 %P steels showed quite similar microstructures including texture. Since the occurrence of delamination requires relatively weak interfaces or planes, P segregated to the ferrite grain boundaries and interfaces of cementite particles-ferrite matrix and made them feasible paths for crack branching and consequently delamination occurred. We showed in this work the advantage of delamination (crack arrester-type) on the high absorbed energy obtained by 0.053 %P steel in comparison with 0.001 %P steel. © (2012) Trans Tech Publications, Switzerland.

关键词： Fracture toughness

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Neuromodulation of the peripheral nervous system:Bioelectronic technology and prospective developments

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BMEMat(BioMedical engineering materials) 2024年第1期2卷 88-114页

作者： Hayoung Song Moohyun Kim Enji Kim Jakyoung Lee Inhea Jeong Kyeonghee Lim Seoung Young Ryu Myoungjae Oh Younhee Kim Jang-Ung Park Department of Materials Science and Engineering Yonsei UniversitySeoulSouth Korea Center for Nanomedicine Institute for Basic Science(IBS)SeoulSouth Korea Department of Neurosurgery Yonsei University College of MedicineSeoulSouth Korea Graduate Program of Nano Biomedical Engineering(NanoBME) Advanced Science InstituteYonsei UniversitySeoulSouth Korea

The peripheral nervous system(PNS)is a fascinatingly complex and crucial component of the human body,responsible for transmitting vital signals throughout the body's intricate network of *** efficient functioning is paramount to our health,with any dysfunction often resulting in serious medical conditions,including motor disorders,neurological diseases,and psychiatric *** strides in science and technology have made neuromodulation of the PNS a promising avenue for addressing these health *** involves modifying nerve activity using a range of techniques,such as electrical,chemical,optical,and mechanical *** plays a critical role in this effort,allowing for precise,controlled,and sustained stimulation of the *** paper provides an overview of the PNS,discusses the current state of neuromodulation devices,and presents emerging trends in the field,including advances in wireless power transfer and materials,that are shaping the future of neuromodulation.

关键词： bioelectronics neuromodulation peripheral nervous system

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Effects of spatial uniformity of continuous and pulse laser irradiation on the microstructure and mechanical properties of Ti-6Al-4V in powder bed fusion

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materials Today Communications 2025年 46卷

作者： Seunghwan Moon Seungmuk Ji Yoonseok Ko Min-Su Lee Tea-Sung Jun Dong-Ik Kim Jong-Souk Yeo School of Integrated Technology College of Computing Yonsei University Seoul 03722 Republic of Korea BK21 Graduate Program in Intelligent Semiconductor Technology Yonsei University Seoul 03722 Republic of Korea Center for Energy Materials Research Korea Institute of Science and Technology Seoul 02792 Republic of Korea Department of Mechanical Engineering Incheon National University Incheon 22012 Republic of Korea

Powder bed fusion of metals with laser beam (PBF-LB/M) using Ti-6Al-4V (Ti64) has enabled delicate fabrication of biocompatible medical implants. This research focuses on how the spatial uniformity of laser irradiation affects material under continuous wave (CW) and pulse width modulated (PWM) laser conditions, using a self-developed PBF-LB/M system. The volumetric energy density (VED) was used as a reference parameter in order to accurately compare the effects of CW and PWM lasers, but limitations of VED, which does not include spatial and kinetic factors, which are reinforced in the PWM laser process, were also considered. Results revealed that the uniform distribution of energy irradiation across the entire region brought similar porosities and Vickers hardness tendencies for CW and PWM laser processes. In contrast, the spatially nonuniform energy transfer resulted in a significantly higher porosity in the specimen fabricated using the PWM laser than that produced using the CW laser at the same VED, reducing compressive yield strength. The electron backscattered diffraction analysis showed no significant differences in the average grain size, phase distribution, and misorientation angle of the samples produced using CW and PWM lasers under the same VED. However, sharper grains with an aspect ratio of less than 0.3 were 7 % higher in specimens produced using the PWM laser. This study highlights the possibility of controlling the microstructure and mechanical properties in a wider range when using the PWM laser with spatially nonuniform irradiation.

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Finite-temperature anisotropic elastic properties of Ni-Mn-In magnetic shape memory alloy

Finite-temperature anisotropic elastic properties of Ni-Mn-I...

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作者： Williams, Kristen S. Cagin, Tahir Materials Science and Engineering Graduate Program Texas A and M University College Station TX United States Department of Chemical Engineering Texas A and M University College Station TX United States

ISBN: (纸本)9781617822018

Designing magnetic shape memory materials with practicable engineering applications requires a thorough understanding of their electronic, magnetic, and mechanical properties. Experimental and computational studies on such materials provide differing perspectives on the same problems, with theoretical approaches offering fundamental insight into complex experimental phenomena. Many recent computational approaches have focused on first-principles calculations, all of which have been successful in reproducing ground-state structures and properties such as lattice parameters, magnetic moments, electronic density of states, and phonon dispersion curves. With all of these successes, however, such methods fail to include the effects of finite temperatures, effects which are critical in understanding how these properties couple to the experimentally-observed martensitic transformation. To this end, we apply the quasi-harmonic theory of lattice dynamics to predict the finite-temperature mechanical properties of Ni-Mn-In magnetic shape memory alloy. We employ first-principles calculations in which we include vibrational contributions to the free energy. By constructing a free energy surface in volume/temperature space, we are able to evaluate key thermodynamic properties such as entropy, enthalpy, and specific heat. We further report the elastic constants for the austenite and martensite phases and evaluate their role as a driving force for martensitic transformation. © 2010 materials Research Society.

关键词： Magnetic moments

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Low-temperature sintered LZSA cellular glass ceramics

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6th Pacific Rim Conference on Ceramic and Glass Technology, PacRim6

作者： Sousa, E. Rambo, C.R. Hotza, D. De Oliveira, A.P. Novaes Fey, T. Graduate Program on Materials Science and Engineering - PGMAT Department of Chemical Engineering - EQA Federal University of Santa Catarina P.O. Box 476 88040-900 Florianópolis SC Brazil Department of Materials Science Glass and Ceramics University of Erlangen-Nuremberg Martensstrasse 5 D-91058 Erlangen Germany

ISBN: (纸本)0470080507

Commercial polyurethane foams with a monomodal pore size distribution were used to produce LZSA glass ceramic foams by the polymeric sponge method. A suspension containing LZSA glass ceramic, bentonite and sodium silicate, was prepared in water and isopropanol media to impregnate the polymeric foams by dip coating. The suspension was characterized by Theological measurements. The effect of the solvent on the microstructure and physical properties on the LZSA foams was also evaluated. The cellular microstructure of the glass-ceramic foams was characterized by scanning electron microscopy (SEM) and micro-computer X-ray tomography (μ-CT). The LZSA foam prepared with isopropanol suspension exhibited higher mechanical strength under compression than those prepared with water.

关键词： Glass ceramics

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Magnetoresistance effect of tunnel junctions using Co2(Ti, Mn)Z (Z Al, Si) Heusler alloys

Magnetoresistance effect of tunnel junctions using Co2(Ti, M...

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作者： Sasaki, A. Tezuka, N. Jiang, L. Sugimoto, S. Department of Materials Science Graduate School of Engineering Tohoku University 6-6-02 Aobayama Sendai 980-8579 Japan Global COE Program Material Integration Tohoku University Sendai Japan

We investigated postannealing temperature dependence of the structural and magnetic properties of Co2Ti0.5Mn0.5Al and Co2Ti0.5Mn0.5Si films. It was observed that the Co2Ti0.5Mn0.5Al film formed an ordered L2 1 structure and an ordered B2 structure after postannealing at above 873 K and below 773 K, respectively. The Co2Ti0.5Mn 0.5Si film deposited with substrate heating at above 473 K formed an ordered L21 structure. The obtained magnetoresistance ratio for a junction using an L21 ordered Co2Ti0.5Mn 0.5Si electrode was 12.5 at room temperature (RT). The estimated spin polarization of the Co2Ti0.5Mn0.5Si film was 0.14 at RT. The magnetoresistance ratios of a junction using a B2 ordered Co2Ti0.5Mn0.5Al electrode were 65.8 at RT and 128.4% at 7 K. The estimated spin polarizations of the Co2Ti 0.5Mn0.5Al film were 0.56 at RT and 0.78 at 7 K. © 2011 American Institute of Physics.

关键词： Room temperature

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One step sol-gel method for the formation of etch free texturing, anti-reflection coatings, and p-n junction for silicon solar cells

One step sol-gel method for the formation of etch free textu...

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作者： Bae, H.J. Kang, S.M. Kim, T.S. Yoon, D.H. Interdisciplinary Graduate School Program for Photovoltaic Specialist Sungkyunkwan University Suwon 440-746 Korea Republic of School of Advanced Materials Science and Engineering Sungkyunkwan University Suwon 440-746 Korea Republic of

This study evaluated one step sol-gel process for the simultaneous formation of surface texturing without a series of chemical etching processes, as well as anti-reflection coatings without complicated vacuum processes and p-n junctions. The solutions for this process were prepared from a proper combination of precursors containing phosphorus and nano-size silicon dioxide particles. The specimen heat treated at 1000 °C showed the lowest reflectivity of 9% at a wavelength of 650 nm. In addition, the I-V test confirmed formation of a p-n junction. Therefore, the production of solar cells may be reduced to two steps, sol-gel and electrode printing. © 2011 Elsevier B.V. All rights reserved.

关键词： Antireflection coatings

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Structure of finite sphere packings via exact enumeration: Implications for colloidal crystal nucleation

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Physical Review E 2012年第5期85卷 051403-051403页

作者： Robert S. Hoy Jared Harwayne-Gidansky Corey S. O’Hern Department of Mechanical Engineering & Materials Science Department of Physics and Integrated Graduate Program in Physical and Engineering Biology Yale University New Haven Connecticut USA

We analyze the geometric structure and mechanical stability of a complete set of isostatic and hyperstatic sphere packings obtained via exact enumeration. The number of nonisomorphic isostatic packings grows exponentially with the number of spheres N, and their diversity of structure and symmetry increases with increasing N and decreases with increasing hyperstaticity H≡Nc−NISO, where Nc is the number of pair contacts and NISO=3N−6. Maximally contacting packings are in general neither the densest nor the most symmetric. Analyses of local structure show that the fraction f of nuclei with order compatible with the bulk (rhcp) crystal decreases sharply with increasing N due to a high propensity for stacking faults, five- and near-fivefold symmetric structures, and other motifs that preclude rhcp order. While f increases with increasing H, a significant fraction of hyperstatic nuclei for N as small as 11 retain non-rhcp structure. Classical theories of nucleation that consider only spherical nuclei, or only nuclei with the same ordering as the bulk crystal, cannot capture such effects. Our results provide an explanation for the failure of classical nucleation theory for hard-sphere systems of N≲10 particles; we argue that in this size regime, it is essential to consider nuclei of unconstrained geometry. Our results are also applicable to understanding kinetic arrest and jamming in systems that interact via hard-core-like repulsive and short-ranged attractive interactions.

关键词： COLLOIDAL crystals NUCLEATION GEOMETRIC analysis SYMMETRY (Physics) EXPONENTIAL functions CRYSTAL structure MAXIMAL functions

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