Search

Your search keyword '"Tran Van Chau"' showing total 7 results
Start Over Author "Tran Van Chau" Publication Year Range Last 50 years
7 results on '"Tran Van Chau"'

1. Effects of scanning methods on cracking, microstructures and microhardness of Inconel 625 parts formed by direct laser metal deposition

Author

Khoa Tat Doan, Le Van Thao, Duong Van Nguy, and Tran Van Chau

Subjects
direct laser metal deposition, scanning method, inconel 625, residual stress, crack, microstructure, Engineering (General). Civil engineering (General), TA1-2040, Technology (General), T1-995, Manufactures, TS1-2301
Abstract

This study aims at investigating the effects of scanning methods on the stress distribution and microstructures of Inconel 625 thin-walled part fabricated by direct laser metal deposition. The results showed that with the single direction scanning (SDS) method, the residual stress at both the ends of the thin wall was relatively high while the stress at the middle was smaller with a stress difference of about 1800 MPa. In contrast, with the reverse direction scanning (RDS) method, the residual stress in the thin wall was distributed relatively evenly, with a stress difference of about 350 MPa between both the ends and the center. The experimental results showed that, in the SDS method, cracks occurred at both ends and in the middle of the thin wall, whereas in the RDS method, warping and cracks phenomena were eliminated. The microstructure of the Inconel 625 in the forming layer is characterized by a columnar crystal structure that has a small length and grows perpendicularly to the scanning direction. This growth is continuous between the forming layers. In both cases, the microhardness increases with the height of the formed layers. The microhardness values are relatively uniform with values ranging from 420 to 450 HV.

Published
2024
Full Text
View/download PDF

2. Thermal Analysis in Wire Arc Additively Manufactured SS308L Walls via Numerical Simulations

Author

Bui, Manh Cuong, Le, Van Thao, Ta, Dinh Xuan, Mai, Dinh Si, Dinh, Duc Manh, Doan, Tat Khoa, Tran, Van Chau, Cavas-Martínez, Francisco, Editorial Board Member, Chaari, Fakher, Series Editor, di Mare, Francesca, Editorial Board Member, Gherardini, Francesco, Series Editor, Haddar, Mohamed, Editorial Board Member, Ivanov, Vitalii, Series Editor, Kwon, Young W., Editorial Board Member, Trojanowska, Justyna, Editorial Board Member, Long, Banh Tien, editor, Kim, Hyung Sun, editor, Ishizaki, Kozo, editor, Toan, Nguyen Duc, editor, Parinov, Ivan A., editor, and Kim, Yun-Hea, editor

Published
2022
Full Text
View/download PDF

7. Research Synthesis of La3+ Doped TiO2 Nanoparticles by Hydrothermal Method, Study on Photocatalytic Activity of Decomposition of Methylene Blue under Ultraviolet Irradiation

Author

Nguyen Thi Mai, Tran Thi Thu Huyen, Tran Van Chau, Ta Ngoc Dung, Huynh Dang Chinh, Nguyen Thi Phuong Lan, and Do Thi Minh Hue

Subjects
chemistry.chemical_compound, Materials science, chemistry, Doping, Tio2 nanoparticles, Photocatalysis, Ultraviolet irradiation, Photochemistry, Decomposition, Methylene blue, Hydrothermal circulation
Abstract

In this study, with the aim of improving the photocatalytic efficiency of TiO2, we studied the synthesis of La3+ doped TiO2 (with doped rates 1%, 2.5%, 5% mol/mol compared to Ti4+) by hydrothermal method. The hydrothermal condition was set at 180 °C for 12 hours. Material characteristics were investigated by XRD, SEM and solid UV-Vis methods. The results show that, all prepared materials have a crystal particle size of about nano-meters, small and smooth (4.5¸6.5 nm). La3+ doped TiO2 samples had a shift towards longer wavelengths (l» 400¸500 nm) compared to non-doped TiO2 sample (l£ 380 nm). The band gap energy (Eg) of La3+ doped TiO2 samples was reduced to 3.04¸3.10 eV . The yield of MB degradation of La3+ doped TiO2 at 5% mol/mol reached the highest ~93% after 60 minutes under ultraviolet irradiation. Keywords Anatase TiO2, photocatalysis, La3+ doped TiO2, hydrothermal method, ultraviolet irradiation. References [1] D. Nassoko, Y. F. Li, H. Wang, J. L. Li, Y. Z. Li, Y. Yu, Nitrogen-doped TiO2 nanoparticles by using EDTA as nitrogen source and soft template: Simple preparation, mesoporous structure, and photocatalytic activity under visible light, Journal of Alloys and Compounds. 540 (2012) 228-235. https://doi.org/10.1016/j.jallcom.2012.06.085.[2] M. Khatamian, S. Hashemian, A. Yavari, M. Saket, Preparation of metal ion (Fe3+ and Ni2+) doped TiO2 nanoparticles supported on ZSM-5 zeolite and investigation of its photocatalytic activity, Materials Science and Engineering B. 177 (2012) 1623-1627. http://dx.doi.org/10.1016/ j.mseb.2012.08.015.[3] X. Zhang, Q. Liu, Visible-light-induced degradation of formaldehyde over titania photocatalyst co-doped with nitrogen and nickel, Applied surface Science. 254(15) (2008) 4780-4785. https://doi.org/10.1016/j.apsusc.2008.01.094.[4] Y. Wang, H. Cheng, L. Zhang, Y. Hao, J. Ma, B. Xu, W. Li, The preparation, characterization, photoelectrochemical and photocatalytic properties of lanthanide metal-ion-doped TiO2 nanoparticles, Journal of Molecular Catalysis A: Chemical. 151 (2000) 205-216. https://doi.org/10. 1016/s 1381-1169(99)00245-9[5] M. Meksi, G. Berhault, C. Guillard, H. Kochkar, Design of TiO2 nanorods and nanotubes doped with lanthanum and comparative kinetic study in the photodegradation of formic acid, Catalysis Communications. 61 (2015) 107-111. https://doi. org/ 10.1016/j.catcom.2014.12.020.[6] Q. Wang, S. Xu, F. Shen, Preparation and characterization of TiO2 photocatalysts co-doped with iron (III) and lanthanum for the degradation of organic pollutants, Applied Surface Science. 257 (2011) 7671-7677. https://doi.org/10.1016/j. apsusc.2011.03.157.[7] L. Elsellami, H. Lachheb, A. Houas, Synthesis, characterization and photocatalytic activity of Li, Cd-, and La-doped TiO2, Materials Science in Semiconductor Processing. 36 (2015) 103-114. https://doi.org/10.1016/j.mssp.2015.03.032.[8] J. Nie, Y. Mo, B. Zheng, H. Yuan, D. Xiao, Electrochemical fabrication of lanthanum-doped TiO2 nanotube array electrode and investigation of its photoelectrochemical capability, Electrochimica Acta. 90 (2013) 589-596. http://dx.doi.org/10. 1016/j.electacta. 2012.12.049.[9] Y. Chen, Q. Wu, C. Zhou, Q. Jin, Enhanced photocatalytic activity of La and N co-doped TiO2/diatomite composite, Powder Technology. 322 (2017) 296-300. http://dx.doi.org/10.1016/ j.powtec.2017.09.026. [10] I. Ganesh, P. P. Kumar, I. Annapoorna, J. M. Sumliner, M. Ramakrishna, N. Y. Hebalkar, G. Padmanabham, G. Sundararajan, Preparation and characterization of Cu-doped TiO2 materials for electrochemical, photoelectrochemical, and photocatalytic applications, Applied Surface Science, 293 (2014) 229-247. http://dx.doi.org/10. 1016/j.apsusc.2013.12.140.

Published
2019
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results