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Effect of Heat Treatment on Functionally Graded 304l Stainless Steel to Inconel 625 Fabricated by Directed Energy Deposition

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SSRN 2024年

作者： Yang, Zhening Sun, Hui Shang, Shun-Li Liu, Zi-Kui Beese, Allison M. Department of Materials Science and Engineering Pennsylvania State University University ParkPA16802 United States Department of Mechanical Engineering The Pennsylvania State University University ParkPA16802 United States

Defining appropriate heat treatments for compositionally functionally graded materials (FGMs) is challenging due to varying processing conditions in terminal alloys and gradient regions. Therefore, it is critical to investigate the impact of potential heat treatments on phase transformations and the resulting mechanical properties along the entire compositional path. In the present study, we applied heat treatments at 700 °C, 900 °C, and 1150 °C on a stainless steel 304L (SS304L) to Inconel 625 (IN625) FGM fabricated using directed energy deposition (DED) additive manufacturing (AM). The microstructure and hardness, as a function of layer-wise composition and applied heat treatment, were characterized. The applicability of computational methods previously developed by the team to predict experimentally observed phases by the hybrid Scheil-equilibrium approach was evaluated. This approach improves the accuracy of predicting phases formed after heat treatment compared to equilibrium thermodynamic calculations using the overall layer compositions and provides a simple pathway to assist in designing heat treatment for FGMs. © 2024, The Authors. All rights reserved.

关键词： Functionally graded materials

A Standalone Real-Time Gait Phase Detection Using Fuzzy-Logic Implementation in Arduino Nano

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SN Computer science 2022年第1期3卷 21页

作者： Negi, Sachin Garg, Kartik Prajapat, Milind Sharma, Neeraj School of Biomedical Engineering Indian Institute of Technology (BHU) Uttar Pradesh Varanasi India Department of Mechanical Engineering Indian Institute of Technology (BHU) Uttar Pradesh Varanasi India School of Materials Science and Technology Indian Institute of Technology (BHU) Uttar Pradesh Varanasi India Department of Electrical Engineering G. B. Pant Institute of Engineering and Technology Uttarakhand Pauri India

This paper presents a real-time standalone computing system's design and development using an Arduino Nano controller for human gait phase detection. It acquires the lower limb segment angles using 3-inertial measurement units and foot insole-based force data using 2-force sensitive resistor sensors for each leg. Arduino IDE-based algorithms are designed to get thigh, shank, and foot angles using the I2C protocol. The force information is achieved using an insole that gathers data from the heel and toe regions. A fuzzy logic-based algorithm is developed in the Arduino IDE for the detection of 7-gait phases. MATLAB's neuro-fuzzy designer toolbox is utilized to obtain a rule base for these gait phases. The results showed that the present system gives a prediction accuracy of 89.65 (± 3)% that is good enough, along with a 20 ms prediction time to make it real-time gait phase detection. This study finds the application of a fuzzy-logic algorithm for real-time control of the ankle–foot prosthesis in an open space using a standalone system with an amputee. © The Author(s), under exclusive licence to Springer Nature Singapore Pte Ltd 2021.

关键词： ANFIS Arduino IDE Gait phase detection Sugeno FIS Wearable sensors

Coupling Effect of Post-Weld Heat Treatment and Fatigue Damage on the Hydrogen Embrittlement of X80 Steel Welded Joints

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SSRN 2024年

作者： Gao, Zhiwei Wu, Shipin Xiang, Ting Gong, Baoming Deng, Caiyan School of Mechanical Engineering Tianjin University of Technology and Education Tianjin300222 China Tianjin Key Laboratory of Advanced Joining Technology School of Materials Science and Engineering Tianjin University Tianjin300072 China

The influence of post-weld heat treatment (PWHT) and fatigue damage on the hydrogen embrittlement sensitivity of X80 steel welded joints were investigated. Compared to the as-welded specimens, the sensitivity of hydrogen embrittlement after PWHT was decreased. However, the coupling effect of PWHT and fatigue damage improved significantly the HE sensitivity. Furthermore, the fracture site of the PWHT + pre-fatigue specimens with hydrogen-charged was transferred to the weld metal, and the fracture was characterized by intergranular fracture, quasi-cleavage (QC) and shallow dimples ductile fracture. The increase of the hydrogen content might be attributed to the evolutions of dislocation and the proportion of high-angle grain boundary caused by fatigue damage. Meanwhile, the size of QC for the hydrogen-charged welded joints were related to the degree of fatigue damage, hydrogen content and microstructure strength. © 2024, The Authors. All rights reserved.

关键词： Welds

Microstructure and Wear Behavior of Alxcocuniti (X=0, 0.4, and 1) High-Entropy Alloy Coatings

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SSRN 2023年

作者： Ma, Ming-Xing Xiang, Li-Yang Zhu, Cheng-Jun Liu, Li-Xin Zhu, Lei Wang, Zhi-Xin Zhao, Liang Zhu, Da-Chuan Zhang, De-Liang School of Mechanical Engineering Henan Polytechnic Institute Nanyang47300 China School of Materials and Chemical Engineering Zhongyuan University of Technology Zhengzhou450007 China College of Material Science and Engineering Sichuan University Chengdu610065 China School of Materials Science and Engineering Northeastern University Shenyang110819 China

AlxCoCuNiTi (x = 0, 0.4, and 1) high-entropy alloy coatings on 45 steel substrates were prepared by laser cladding, and their phase structure, microstructure, element partition and wear behavior were investigated. The results show that the AlxCoCuNiTi (x = 0, 0.4, and 1) coatings have a dual-phase structure of FCC and BCC. With the increase of x from 0 to 1, the content of FCC phase decreases from 66.9 mas% to 14.3 mas%, while the content of BCC phase increases from 33.1 mas% to 85.7 mas%. When x=0.4, the lattice constants of the two phases are the largest and their densities are the smallest. The microstructure of the AlxCoCuNiTi (x = 0, 0.4, and 1) coatings is composed of BCC-phase dendrites and FCC-phase interdendritic regions. Ti is mainly enriched in the primary phase or BCC dendrites, Cu is enriched in the interdendritic regions, and Al is enriched in the dendrites. The friction coefficients of AlxCoCuNiTi (x = 0, 0.4, and 1) coatings during wear tests are 0.691, 0.691 and 0.627 respectively. The lowering of wear friction coefficient with increasing the Al content is mainly related to the change of phase structure, microstructure and wear mechanism. © 2023, The Authors. All rights reserved.

关键词： Friction

Nickel Oxide Scale Microstructure and Accelerated Growth in Combustion Flue Gas: Effect of Ash Particles

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SSRN 2023年

作者： Xi, Xuteng Shen, Zhao Zhang, Jianqiang Gleeson, Brian Young, David J. School of Materials Science and Engineering University of New South Wales SydneyNSW2052 Australia University of Oxford United Kingdom Department of Mechanical Engineering and Materials Science University of Pittsburgh PittsburghPA15261 United States

Model Ni-25Cr and Ni-25Cr-2Mn-1Si (wt.%) alloys coated with an industrial fly ash were exposed to a wet CO2 gas at 750 oC. It was found that the outer thermally-grown NiO scale encapsulated ash particles at an accelerated rate. TEM combined with TKD analysis revealed that nano structured NiO grains on the ash surface contributed to the observed NiO encapsulating effect. © 2023, The Authors. All rights reserved.

关键词： Nickel oxide

Plasmonic Nanolaser by Silver Nanowire Embedded in CsPbBr3 Quantum Dots

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Plasmonic Nanolaser by Silver Nanowire Embedded in CsPbBr3 Q...

JSAP-OSA Joint Symposia, JSAP 2021

作者： Xing, Di Lin, Cheng-Chieh Won, Phillip Xiang, Rong Chen, Tzu-Pei A. Kamal, A. Syazwan Lee, Yang-Chun Ho, Ya-Lun Maruyama, Shigeo Ko, Seung Hwan Chen, Chun-Wei Delaunay, Jean-Jacques School of Engineering The University of Tokyo Japan International Graduate Program of Molecular Science and Technology National Taiwan University Taiwan Department of Materials Science and Engineering National Taiwan University Taiwan Department of Mechanical Engineering Seoul National University Korea Republic of Center of Atomic Initiative for New Materials National Taiwan University Taiwan

Comprehensive Study of Microstructure, Phase Transformations, and mechanical Properties of Shape Memory and Superelastic Nitinol and a Novel Approach to Fabricate Belleville Spring Using Wire Arc Additive Manufacturing

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SSRN 2023年

作者： Kumar, Ajit Palani, Iyamperumal Anand Yadav, Muralidhar Department of Mechanical Engineering Indian Institute of Technology Indore Indore453552 India Department of Materials Engineering Indian Institute of Science Bangalore Bengaluru560012 India

In the present work, a novel approach is attempted to manufacture the Belleville spring/washer of Nitinol (NiTi) alloys using wire arc additive manufacturing (WAAM). As part of the development of Belleville springs with their desired mechanical and functional properties, a comparative study was conducted between samples fabricated using WAAM with NiTi wires, which differed in terms of their distinctive characteristics, namely superelasticity (SE) and shape memory (SM) effect. A detailed correlation between the chemical composition, microstructure, and martensite transformation of deposited layers and their mechanical properties has been established. The energy dispersive spectroscopy (EDS) results revealed that the first track deposited using both SE and SM effect wire consisted of significant Fe constituents, which was further reduced while increasing the number of tracks. Moreover, as compared to the sample manufactured with SE effect NiTi wire (S1), the X-ray diffraction (XRD) of the sample manufactured with SM effect NiTi wire (S2) showed a secondary phase like NiTi2 along with the major NiTi (B19’ martensitic). Furthermore, the mechanical properties, microstructure, and phase transformation temperature of both S1 and S2 were investigated and compared. It was found that S2 has a finer microstructure than S1. Also, the compressive strength and hardness of S2 were higher than that of S1. In contrast, the tensile strength of the S2 was found to be lower than the *** manufacturing the Belleville spring using WAAM, S1 showed promising mechanical and martensitic transformation results. © 2023, The Authors. All rights reserved.

关键词： 3D printing

Kinetic and Equilibrium Shapes of Cylindrical Grain Boundaries

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SSRN 2024年

作者： Qiu, Anqi Qiu, Caihao Chesser, Ian Han, Jian Srolovitz, David J. Holm, Elizabeth A. Department of Physics & Astronomy Department of Materials Science and Engineering Carnegie Mellon University PittsburghPA15213 United States Department of Materials Science and Engineering City University of Hong Kong Hong Kong XCP-5 Los Alamos National Laboratory Los Alamos NM87545 United States Department of Mechanical Engineering The University of Hong Kong Hong Kong Department of Materials Science and Engineering University of Michigan Ann ArborMI48109 United States

In this work, we investigate the shape evolution of rotated, embedded, initially cylindrical grains (with [001] cylinder axis) in Ni under an applied synthetic driving force via molecular dynamics simulations and a continuum, disconnection-based grain boundary migration model. For some initial misorientations, the expanding grains form well-defined, faceted shapes, while for others the shapes remain cylindrical. The embedded grains tend to rotate during grain boundary migration, with the direction of rotation dependent on initial misorientation and direction of growth (expand/shrink). The kinetic shapes, which are bounded by low mobility grain boundary planes, differ from equilibrium shapes (bounded by low energy grain boundaries). The multi-mode disconnection model-based predictions are consistent with the molecular dynamics results for faceting tendency, kinetic grain shape, and grain rotation as a function of misorientation and whether the grains are expanding or contracting. This demonstrates that grain boundary migration and associated grain rotation are mediated by disconnection flow along grain boundaries. © 2024, The Authors. All rights reserved.

关键词： Molecular dynamics

通过高通量研究识别用于本征陡坡晶体管的原子级薄孤立能带沟道材料

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science Bulletin 2024年第10期69卷 1427-1436页

作者：屈恒泽张胜利曹江吴振华柴扬李卫胜李连忠任文才王欣然曾海波 MIIT Key Laboratory of Advanced Display Materials and Devices College of Material Science and EngineeringNanjing University of Science and TechnologyNanjing 210094China School of Electronic and Optical Engineering Nanjing University of Science and TechnologyNanjing 210094China Key Laboratory of Microelectronics Device and Integrated Technology Institute of Microelectronics of Chinese Academy of SciencesBeijing 100029China Department of Applied Physics The Hong Kong Polytechnic UniversityHong Kong 999077China National Laboratory of Solid State Microstructures School of Electronic Science and Engineering and Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210023China Department of Mechanical Engineering The University of Hong KongHong Kong 999077China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Integrated Circuits Nanjing UniversitySuzhou 215163China Suzhou Laboratory Suzhou 215009China

Developing low-power FETs holds significant importance in advancing logic circuits,especially as the feature size of MOSFETs approaches sub-10 ***,this has been restricted by the thermionic limitation of SS,which is limited to 60 mV per decade at room ***,we proposed a strategy that utilizes 2D semiconductors with an isolated-band feature as channels to realize subthermionic SS in *** high-throughput calculations,we established a guiding principle that combines the atomic structure and orbital interaction to identify their sub-thermionic transport *** guides us to screen 192 candidates from the 2D material database comprising 1608 ***,the physical relationship between the sub-thermionic transport performances and electronic structures is further revealed,which enables us to predict 15 systems with promising device performances for low-power applications with supply voltage below 0.5 *** work opens a new way for the low-power electronics based on 2D materials and would inspire extensive interests in the experimental exploration of intrinsic steep-slope MOSFETs.

关键词： 2D materials Electronic band structures Transport properties Steep-slope transistors DFT-NEGF calculations