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Relative spectral response calibration using Ti plasma lines

Teng FEI, Congyuan PAN, Qiang ZENG, Qiuping WANG, Xuewei DU
2018 Plasma Science and Technology  
This work introduces the branching ratio (BR) method for determining relative spectral responses, which are needed routinely in laser induced breakdown spectroscopy (LIBS). Neutral and singly ionized Ti lines in the 250-498 nm spectral range are investigated by measuring laser-induced micro plasma near a Ti plate and used to calculate the relative spectral response of an entire LIBS detection system. The results are compared with those of the conventional relative spectral response calibration
more » ... ethod using a tungsten halogen lamp, and certain lines available for the BR method are selected. The study supports the common manner of using BRs to calibrate the detection system in LIBS setups.
doi:10.1088/2058-6272/aaaada fatcat:nkt7s6bml5fkhprm6hjjqsr65y

Titanium and nitrogen interactions under laser additive manufacturing conditions

Congyuan Zeng, Hao Wen, Henry Bellamy, Phillip Sprunger, Paul J. Schilling, S.M. Guo
2019 Surface & Coatings Technology  
To understand how to make bulk titanium parts or coatings with desired levels of titanium nitrides, this paper investigates the dynamic interactions between titanium and nitrogen under representative laser-based additive manufacturing (AM) conditions. Under a set of gas environments containing different concentrations of nitrogen, the titanium and nitrogen reaction products-formed under typical Selective Laser Melting (SLM) and Laser Engineered Net Shaping (LENS) AM scanning conditions-are
more » ... ned for compositions, phases, and microstructures. In-situ synchrotron X-ray diffraction (SXRD) test is performed to reveal the high temperature reaction steps between titanium and nitrogen.
doi:10.1016/j.surfcoat.2019.124955 fatcat:vuumaezh5vbzrcs4yx7lh327ma

Microstructure Evolution of Al6061 Alloy Made by Additive Friction Stir Deposition

Congyuan Zeng, Hamed Ghadimi, Huan Ding, Saber Nemati, Abdelrahman Garbie, Jonathan Raush, Shengmin Guo
2022 Materials  
In this paper, the phase structure, composition distribution, grain morphology, and hardness of Al6061 alloy samples made with additive friction stir deposition (AFS-D) were examined. A nearly symmetrical layer-by-layer structure was observed in the cross section (vertical with respect to the fabrication-tool traversing direction) of the as-deposited Al6061 alloy samples made with a back-and-forth AFS-D strategy. Equiaxed grains were observed in the region underneath the fabrication tool, while
more » ... elongated grains were seen in the "flash region" along the mass flow direction. No clear grain size variance was discovered along the AFS-D build direction except for the last deposited layer. Grains were significantly refined from the feedstock (~163.5 µm) to as-deposited Al6061 alloy parts (~8.5 µm). The hardness of the as-fabricated Al6061 alloy was lower than those of the feedstock and their heat-treated counterparts, which was ascribed to the decreased precipitate content and enlarged precipitate size.
doi:10.3390/ma15103676 pmid:35629701 pmcid:PMC9145620 fatcat:mr5i3ixjifb6hdp5zs2mzmhtki

Performance of Carbide Alloy Compounds in Carbon Doped MoNbTaW

Congyan Zhang, Uttam Bhandari, Jialin Lei, Congyuan Zeng, Shengmin Guo, Hyunjoo Choi, Seungjin Nam, Jinyuan Yan, Shizhong Yang, Feng Gao
2021 Crystals  
In this work, the performance of the carbon doped compositionally complex alloy (CCA) MoNbTaW was studied under ambient and high pressure and high temperature conditions. TaC and NbC carbides were formed when a large concentration of carbon was introduced while synthesizing the MoNbTaW alloy. Both FCC carbides and BCC CCA phases were detected in the sample compound at room temperature, in which the BCC phase was believed to have only refractory elements MoNbTaW while FCC carbide came from TaC
more » ... d NbC. Carbides in the carbon doped MoNbTaW alloy were very stable since no phase transition was obtained even under 3.1 GPa and 870 °C by employing the resistor-heating diamond anvil cell (DAC) synchrotron X-ray diffraction technique. Via in situ examination, this study confirms the stability of carbides and MoNbTaW in the carbon doped CCA even under high pressure and high temperature.
doi:10.3390/cryst11091073 fatcat:tsqmbeixrvgvjltfwbgtbesptm

Deep Learning-Based Hardness Prediction of Novel Refractory High-Entropy Alloys with Experimental Validation

Uttam Bhandari, Congyan Zhang, Congyuan Zeng, Shengmin Guo, Aashish Adhikari, Shizhong Yang
2021 Crystals  
(Congyuan Zeng), A.A.; validation, C.Z. (Congyan Zhang), S.G. and S.Y.; formal analysis, C.Z. (Congyuan Zeng), and S.G; investigation, U.B., and C.Z.  ...  (Congyuan Zeng) and S.Y; writing-review and editing, S.G. and S.Y; visualization, S.Y.; supervision, S.Y.; project administration, S.Y.; funding acquisition, S.Y.  ... 
doi:10.3390/cryst11010046 fatcat:f22yyuxfbbgzhhprwvxn2y53ri

Computational and experimental investigation of refractory high entropy alloy Mo15Nb20Re15Ta30W20

Uttam Bhandari, Congyan Zhang, Congyuan Zeng, Shengmin Guo, Shizhong Yang
2020 Journal of Materials Research and Technology  
j m a t e r r e s t e c h n o l . 2 0 2 0;9(x x):8929-8936 w w w . j m r t . c o m . b r a b s t r a c t In this study, refractory high entropy alloys (RHEAs) Mo were studied by applying the firstprinciples density functional theory (DFT) method. The DFT calculation was based on a large unit cell model of 100-atom supercell, with randomly distributed five element atoms. The mechanical properties of all three RHEAs were calculated and compared. Comparing with the other two RHEAs, Mo 15 Nb 20 Re
more » ... 5 Ta 30 W 20 possesses balanced mechanical properties with an optimized concentration of expensive Re element. We combined the DFT calculations of a supercell with Debye-Grüneisen theory to investigate the thermal properties of the two RHEAs was selected for further experimental exploration and the computational results were compared. The experimental study shows the existence of a single BCC structure of Mo 15 Nb 20 Re 15 Ta 30 W 20. The crystal structure, density, lattice parameter, and hardness predicted computationally are consistent with the experiment data. (S. Yang). resistant [7] in comparison with traditional alloys like Inconel 718 and Haynes 230. The extension of HEAs to refractory high entropy alloys (RHEAs) has been reported by Senkov et al. [3,8]. They found MoNbTaW and MoNbTaVW have higher melting points with good mechanical properties at high temperature compared to traditional alloys. Recently, other RHEAs such as TaNbHfZrTi [9], TiZrNbTaMo [10], AlNbTiVZr x [11], MoNbTaTiW [12] have been extensively studied. These RHEAs possess a single body centered cubic (BCC) structure with magnificent mechanical properties than HEAs with face centered cubic (FCC) structure. However, some RHEAs like NbCrMoTaTiZr [13], CrNbTiZr [14] and CrNbTiVZr [15] shows the existence of Laves phase in BCC matrix because of small atomic size of Cr in those RHEAs. The precipitation of Laves phase affects the mechanihttps://doi.
doi:10.1016/j.jmrt.2020.06.036 fatcat:qcwcm7pxebhapmkk6opw4uwm5a

Developing Fused Deposition Modeling Additive Manufacturing Processing Strategies for Aluminum Alloy 7075: Sample Preparation and Metallographic Characterization

Huan Ding, Congyuan Zeng, Jonathan Raush, Kasra Momeni, Shengmin Guo
2022 Materials  
Currently, no commercial aluminum 7000 series filaments are available for making aluminum parts using fused deposition modeling (FDM)-based additive manufacturing (AM). The key technical challenge associated with the FDM of aluminum alloy parts is consolidating the loosely packed alloy powders in the brown-body, separated by thin layers of surface oxides and polymer binders, into a dense structure. Classical pressing and sintering-based powder metallurgy (P/M) technologies are employed in this
more » ... tudy to assist the development of FDM processing strategies for making strong Al7075 AM parts. Relevant FDM processing strategies, including green-body/brown-body formation and the sintering processes, are examined. The microstructures of the P/M-prepared, FDM-like Al7075 specimens are analyzed and compared with commercially available FDM 17-4 steel specimens. We explored the polymer removal and sintering strategies to minimize the pores of FDM-Al7075-sintered parts. Furthermore, the mechanisms that govern the sintering process are discussed.
doi:10.3390/ma15041340 pmid:35207880 pmcid:PMC8877056 fatcat:lbzlrifow5d2xouu7z3n2spah4

Carbide Formation in Refractory Mo15Nb20Re15Ta30W20 Alloy under a Combined High-Pressure and High-Temperature Condition

Congyan Zhang, Uttam Bhandari, Congyuan Zeng, Huan Ding, Shengmin Guo, Jinyuan Yan, Shizhong Yang
2020 Entropy  
In this work, the formation of carbide with the concertation of carbon at 0.1 at.% in refractory high-entropy alloy (RHEA) Mo15Nb20Re15Ta30W20 was studied under both ambient and high-pressure high-temperature conditions. The x-ray diffraction of dilute carbon (C)-doped RHEA under ambient pressure showed that the phases and lattice constant of RHEA were not influenced by the addition of 0.1 at.% C. In contrast, C-doped RHEA showed unexpected phase formation and transformation under combined
more » ... pressure and high-temperature conditions by resistively employing the heated diamond anvil cell (DAC) technique. The new FCC_L12 phase appeared at 6 GPa and 809 ℃ and preserved the ambient temperature and pressure. High-pressure and high-temperature promoted the formation of carbides Ta3C and Nb3C, which are stable and may further improve the mechanical performance of the dilute C-doped alloy Mo15Nb20Re15Ta30W20.
doi:10.3390/e22070718 pmid:33286490 fatcat:ek2hg7admrhyhotmoar2au3akq

In-situ synchrotron X-ray diffraction data for the dynamic reaction processes between titanium and air under laser irradiation

Congyuan Zeng, Hao Wen, Hong Yao, P.T. Sprunger, S.M. Guo
2020 Data in Brief  
This article presents data related to the research article entitled "Diffusion of oxygen and nitrogen into titanium under laser irradiation in air" [1]. When irradiated with varying laser parameters under ambient air, titanium surfaces are observed to exhibit differing colors. To better understand this phenomenon, the dynamic reaction steps between titanium and air under laser irradiation were investigated with in-situ synchrotron X-ray diffraction method. With a programmed laser profile, a set
more » ... of diffraction patterns were collected by a 2D detector and then analyzed with the program FIT2D. Based on the data, the detailed high-temperature reactions between titanium and air during laser irradiation were clearly revealed. The presented raw in-situ synchrotron X-ray diffraction data can be reused for the further insights of laser surface modification of titanium in air, or for discovering the optimal laser conditions for industrial decoration or medical applications of titanium.
doi:10.1016/j.dib.2020.105155 pmid:32368575 pmcid:PMC7187328 fatcat:ionxpr2sx5fgrnope5idddpyle


2012 7th International Conference on Communications and Networking in China  
Finding Community Structure in Complex Network Based on Latent Variables 239 Fuzzing o Shared Path Protection based on Spectrum Reserved Matrix Model in 256 Bandwidth-Variable Optical Networks Congyuan  ...  o 185 VISUAL QUALITY CONTROL FOR PERCEPTUAL VIDEO ENCRYPTION WITH 189 MULTIPLE TRANSFORMS Siu-Kei Au Yeung, Bing Zeng AN INDIVIDUAL-INDICATOR QOE MODEL WITH TEST SAMPLES AND METHODS FOR  ... 
doi:10.1109/chinacom.2012.6417435 fatcat:yuxgt3efxrga3krtm3dlyw344i

Technical Program

2020 2020 15th International Conference on Computer Science & Education (ICCSE)  
Congyuan Jin Wuhan Fiberhome Technical ServicesCo.,Ltd/Fiberhome Design and Implementation of University Continuing Education Informatization Platform Based on SaaS Model, pp. 253-256.  ...  ., Ltd Siwei Wei 2020-8-20 8:30 -10:30 ThC1.8 CCCC Second Highway Consultants Co, Ltd Yong Zeng How to Promote the Development of Youth Information Technology Education in China through Programming Ability  ... 
doi:10.1109/iccse49874.2020.9201784 fatcat:lt6rvw7govdinjzuzsiy6twn74

Origin and formation of carbonaceous material veins in the 2008 Wenchuan earthquake fault zone

Jiang Liu, Haibing Li, Jinjiang Zhang, Bo Zhang
2016 Earth, Planets and Space  
Acknowledgements We thank Yang Wang, Congyuan Yin, and Meng Wang of the EBSD laboratory of Peking University for their help with SEM imaging and thank Marie-Luce Chevalier for improving the English writing  ...  It generated a~230-km-long surface rupture zone along the central fault of the Longmen Shan fault belt, the Yingxiu-Beichuan fault (YBF) Xu et al. 2009; Liu-Zeng et al. 2010; Fu et al. 2011; Lin 2011)  ...  surface rupture zone of Wenchuan earthquake was located at the southern boundary of the fault zone and thrust fault rocks onto the alluvial deposits by a vertical displacement of~6 m Xu et al. 2009; Liu-Zeng  ... 
doi:10.1186/s40623-016-0399-z fatcat:cim66cndbbf3zl6we6yu55ajg4

The influence mechanism of nanoparticles on the dielectric properties of epoxy resin

Rui Wang, Congzhen Xie, Shoukang Luo, Bin Gou, Huasong Xu, Leilei Zeng
2019 RSC Advances  
Acetone and silane coupling agent KH-560 were purchased from Guangzhou Congyuan Instrument Co., Ltd, China. Sample preparation The nanocomposites were prepared as follows.  ... 
doi:10.1039/c9ra02889g pmid:35519404 pmcid:PMC9065294 fatcat:zbpot65wnzgxjb4uvywlr67uee

Thermal decomposition behavior and kinetics of nanocomposites at low-modified ZnO content

Rui Wang, Congzhen Xie, Leilei Zeng, Huasong Xu
2019 RSC Advances  
The titanate coupling agent (TCA) used as a surface treatment agent was purchased from Guangzhou Congyuan Instrument Co., Ltd, China.  ... 
doi:10.1039/c8ra09206k pmid:35517628 pmcid:PMC9059490 fatcat:duf4zb6wwbcqna7b7b7xppym4q

A Deep Learning-Based Method for Automatic Assessment of Stomatal Index in Wheat Microscopic Images of Leaf Epidermis

Chuancheng Zhu, Yusong Hu, Hude Mao, Shumin Li, Fangfang Li, Congyuan Zhao, Lin Luo, Weizhen Liu, Xiaohui Yuan
2021 Frontiers in Plant Science  
., 2019) and nuclei segmentation (Zeng et al., 2019) were based on the U-Net structure.  ... 
doi:10.3389/fpls.2021.716784 pmid:34539710 pmcid:PMC8446633 fatcat:aejviqjqdrezvlpr7gyqzaap5y
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