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Start Over Author "Gong, Feng" Publisher elsevier b.v.
203 results on '"Gong, Feng"'

35. Superior high-temperature wear resistance of an Ir-Ta-Ni-Nb bulk metallic glass.

Author

Sun, Fei, Deng, Shengtao, Fu, Jianan, Zhu, Jiahua, Liang, Dandan, Wang, Pengfei, Zhao, Hang, Gong, Feng, Ma, Jiang, Liu, Yanhui, and Shen, Jun

Subjects
WEAR resistance, MECHANICAL wear, METALLURGY, HIGH temperatures, EXTREME environments
Abstract

• The high temperature wear behavior and wear mechanisms of a novel Ir-Ta-Ni-Nb bulk metallic glass were investigated. • The superior high temperature wear resistance of Ir-Ta-Ni-Nb bulk metallic glass compared to other reported metallic glass systems was demonstrated. • The oxidation behavior of Ir-Ta-Ni-Nb bulk metallic glass during high temperature wear was studied. Wear resistance is a critical consideration in engineering applications. In this study, we demonstrated an Ir-Ta-Ni-Nb bulk metallic glass (BMG) with outstanding high-temperature wear resistance and revealed its promising applications in extreme environments. The wear behavior and mechanism were systematically investigated from room temperature (RT) to 750 °C. The results show that the wear rate increases from ∼2.65 × 10−6 mm3 N−1 m−1 to ∼10.56 × 10−6 mm3 N−1 m−1 in the temperature span RT to 400 °C, following abrasive wear and flash temperature-induced oxidative wear during the friction. However, at the higher temperature of 600 °C, further heating due to frictional heat leads to a softening of the wear surface, resulting in a maximum wear rate of ∼20.99 × 10−6 mm3 N−1 m−1 under softness-driven abrasive wear as well as oxidative wear. Interestingly, the wear resistance at an even higher temperature of 750 °C shows a paradoxical improvement of ∼7.08 × 10−6 mm3 N−1 m−1, which is attributed to the formation of an oxide layer with a thickness of several microns, avoiding violent wear of BMG. The results demonstrate the unreported outstanding high-temperature wear resistance of the Ir-Ta-Ni-Nb BMG, especially its excellent capability to resist wear at 750 °C, leading to the promising applications of BMG in the fields of aerospace, metallurgy, and nuclear industries. [ABSTRACT FROM AUTHOR]

Published
2023
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36. Understanding the effect of Pt doping on the microstructure, mechanical and tribological properties of CrN coating.

Author

Gong, Feng, Wang, Yihe, Zhang, Weilun, Ren, Hao, Li, Jie, and Xie, Zhiwen

Subjects
*SURFACE coatings, *SURFACE texture, *WEAR resistance, *MICROSTRUCTURE, *DOPING agents (Chemistry), *SLIDING wear
Abstract

This study investigated the effect of Pt doping on the microstructure, mechanical and tribological property of the CrN coating. Results showed that this CrN coating exhibited a loose columnar texture and a rough surface with a high Ra value of 3.07 ± 0.035 nm. A prominent coherent growth within the grain appeared in this coating, which provides strong bond strength of coating texture resulting in a high H/E ratio of 0.083. This CrN coating showed an unidirection scratch fracture, but also possessed good wear resistance with a smooth wear track. Pt doping induced a nearly single preferential growth of (200) plane, and resulted in a dense columnar texture and a smooth surface. The Ra value was 2.71 ± 0.285 nm for the CrN–Pt 9.55 coating, and decreased to 1.04 ± 0.14 nm for the CrN–Pt 17.73 coating. However, Pt atoms greatly blocked the coherent growth within the grain, and further degraded the bond strength of coating texture. The CrN–Pt 9.55 coating showed serious multidirection scratch fracture, but also experienced severe wear accompanied with numerous cracks and adhesive debris. In contrast, the hindrance effect and mechanical degradation were further strengthened with the increase of Pt doping content. This CrN–Pt 17.73 coating suffered from most severe fracture damage and debris adhesion during the scratch and sliding wear tests. [ABSTRACT FROM AUTHOR]

Published
2023
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37. Study on warpage and filling behavior of glass in non-isothermal hot embossing.

Author

Li, Jianzhi, Gong, Feng, and Yang, Gao

Subjects
*OPTICAL glass, *FOCUSED ion beams, *GLASS, *MASS production, *SILICON carbide
Abstract

Non-isothermal hot embossing has great potential in the mass production of glass micro optical components due to the relatively short heating-cooling cycle time. However, warpage was induced by the temperature gradient inside the glass replica during hot embossing, resulting in a deteriorated optical performance. Therefore, it is non-trivial to investigate the effects of process parameters on warping and filling behaviors of glass in non-isothermal hot embossing. Firstly, a high-quality microhole was fabricated on monocrystalline silicon carbide (SiC) mold by focused ion beam (FIB) lithography. By using a novel home-made gravity-assisted hot embossing machine, the geometric information (i.e., warpage and microstructures) on SiC mold was transferred into the surface of N-BK7 glass replica. The experimental results indicate that high embossing temperature enables not only the minimization of warpage but also the enhancement of microstructure replication accuracy. Furthermore, increasing embossing force enhances filling capacity but increases warpage amplitude. Interestingly, fast heating/cooling rates and short embossing time enable a small warpage as well as a high embossing efficiency. By optimizing the process parameters, especially the embossing temperature, a small warpage amplitude of 3 μm and a high transfer ratio of 99.11% were achieved, which can meet the high requirement of precision optical components. [ABSTRACT FROM AUTHOR]

Published
2023
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46. Activating the synergistic effect in Ni-Co bimetallic MOF for enhanced plasma-assisted ammonia synthesis.

Author

Jing, Yuhang, Gong, Feng, Wang, Sijun, Wang, Wenbin, Yang, Peng, Fu, Enkang, and Xiao, Rui

Subjects
*ATMOSPHERIC pressure, *AMMONIA, *ALUMINUM oxide, *LATENT variables, *RENEWABLE energy sources, *NITROGEN, *MASS transfer
Abstract

[Display omitted] • Novel strategy of bimetallic MOFs for enhanced PAAS is designed. • The enhanced PAAS is ascribed to the improved mass transfer in MOFs. • Sustainable NH 3 production rate achieves 77.5 μmol g−1·min−1 in 36 h or ∼ 30 cycles. • Hypothetical zero-carbon ammonia plant exhibits notable competitiveness. Plasma-assisted ammonia synthesis (PAAS) can produce ammonia using highly energetic, electronically excited nitrogen and Hydrogen radicals at low temperatures and atmospheric pressure, which has been regarded as a prospective alternative to the Haber − Bosch process. PAAS can exclusively use renewable power (solar, wind, etc.) to achieve green, decentralized and efficient ammonia synthesis. However, current catalysts for PAAS are suffering from low efficiency, poor stability and cyclability. Herein, we demonstrate a one-step hydrothermal synthesis of Ni-Co bimetallic metal–organic frameworks (MOFs) for PAAS. Attributed to the amplified gas transport capability and bimetallic coupling, the Ni-Co-MOF exhibits significantly improved PAAS performance: 88.21 μmol g−1·min−1, above 30 % increase over 5 wt% Ni/Al 2 O 3. The high stability of Ni-Co-MOF under the harsh electric field enables its durable performance (36 h) and excellent cyclability (24 cycles). Finally, to determine the viability of PAAS for industrial applications, we construct a hypothetical zero-carbon ammonia plant using only renewable energy sources, and the outcomes indicate that PAAS has significant competitiveness for future ammonia production. [ABSTRACT FROM AUTHOR]

Published
2024
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