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Chau, Joseph Lik Hang;Pan, Alfred I-Tsung;Yang, Chih-Chao
- Advances in materials Research
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- v.6 no.4
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- pp.343-348
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- 2017
High-pressure gas atomization was employed to prepare the Fe-based $Fe_{50}Cr_{24}Mo_{21}Si_2B_3$ alloy powder. The effect of flow rate of atomizing gas on the median powder diameter was studied. The results show that the powder size decreased with increasing the flow rate of atomizing gas. Fe-based alloy coatings with amorphous phase fraction was then prepared by high velocity oxygen fuel spraying (HVOF) of gas atomized $Fe_{50}Cr_{24}Mo_{21}Si_2B_3$ powder. Microstructural studies show that the coatings present dense layered structure and low porosity of 0.17% in about $200{\mu}m$ thickness. The Fe-based alloy coating exhibits an average hardness of about 1230 HV. Our results show that the HVOF process results in dense and well-bonded coatings, making it attractive for protective coatings applications.
https://doi.org/10.12989/amr.2017.6.4.343 인용 KSCI

Inoue, Chihiro;Watanabe, Toshinori;Himeno, Takehiro
- Proceedings of the Korean Society of Propulsion Engineers Conference
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- 2008.03a
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- pp.371-377
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- 2008
In order to obtain fundamental knowledge of atomization, the three dimensional unsteady phenomenon of pinch off was numerically studied by developed method. Not only liquid shapes but also velocity distributions of numerical results were compared with corresponding experimental ones. They showed satisfactorily good agreement at least in a qualitative sense. The liquid jet shapes, the pressure and velocity distributions, and the inner flow structures were clarified through the comparisons of distinctly different flow fields due to presence or absence of surface tension. The condition of pinch off, which had close correlation with fluid acceleration at injection, was clearly specified.
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Lee, Mun Hee;Hong, Jung Goo
- Journal of ILASS-Korea
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- v.24 no.3
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- pp.145-151
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- 2019
Viscoelastic fluid is used in various industrial sites because its cost reduction and environmental benefits by preventing formation of fine droplets that scattered around. However, viscoelastic fluids, unlike newtonian fluids, contain a shear thinning characteristic that decrease in viscosity as shear rate increases and elastic characteristic, making it difficult to predict spray breakup process. In this study we made three test fluids. Boger fluid with viscoelastic characteristics, and two newtonian fluids, were prepared to exclude shear thinning characteristics and study the effects of elastic characteristic only. Flow visualization, spray angle, and SMD were measured for three test fluids using laboratory scale impinging jet test apparatus. As a result, it was confirmed that Boger fluid, unlike the newtonian fluid, was not formed fine droplets that scattered around and the breakup process appeared differently. In addition, SMD was found to be large in Boger fluid, and the SMD according to pressure was confirmed that there is no significant difference.
https://doi.org/10.15435/JILASSKR.2019.24.3.145 인용 PDF KSCI