Acta Metall Sin  2020, Vol. 56 Issue (5): 785-794    DOI: 10.11900/0412.1961.2019.00299
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Effect of Temperature on Mechanical Propertiesof Carbon Nanotubes-Reinforced Nickel Nano-Honeycombs
LI Yuancai, JIANG Wugui(), ZHOU Yu
School of Aeronautical Manufacturing Engineering, Nanchang Hangkong University, Nanchang 330063, China
Abstract

Nickel nano-honeycombs (NNHC) would be expected to an ideal anode material for solid oxide fuel cells (SOFC) because of its high surface area and highly ordered pore network. But, the anode material requires excellent mechanical properties to withstand stresses that arise during processing and service at different temperatures. The influence of temperature on the mechanical behaviors under radial (y axis) tension, radial compression, axial (z axis) tension and axial compression, is investigated by molecular dynamics (MD) by taking the carbon nanotubes (CNT)-reinforced NNHC (CRNNHC) composites with the mass fractions of CNT (ωCNT) of 5.22‰ and its corresponding NNHC as the example. The results show that the mechanical properties including elastic modulus(E) and ultimate stress (σu)in NNHC and CRNNHC both decrease approximately linearly with the increase of temperature. Compared to NNHC, the addition of CNT has no obvious effect on the enhancement of radial mechanical properties of CRNNHC under different temperatures, but it results in a good reinforced effect on axial mechanical properties. While the axial tensile and compressive elastic moduli can be increased by 6.4%~10% and 9%~12% respectively, and the ultimate stress can be increased by 1.5%~5.3% and 10%~14% respectively. The study indicates that axial mechanical properties of the CRNNHC are generally superior to their radial mechanical properties, and the energy absorption before the axial deformation is relatively larger due to the existence of CNT.

 ZTFLH: TB31
Fund: National Natural Science Foundation of China(11772145);National Natural Science Foundation of China(11372126)
Corresponding Authors:  JIANG Wugui     E-mail:  jiangwugui@nchu.edu.cn
 Fig.1  Molecular dynamics (MD) model in this work (R—radius of pore, CNT—carbon nanotube, NNHC－nickel nano-honeycombs, CRNNHC—CNT-reinforced NNHC)(a) the model of CRNNHC(b) the size distribution of CRNNHC(c) the internal distribution of CNT in the CRNNHC Fig.2  The radial tensile stress-strain curves of NNHC (a) and CRNNHC (b) with different temperatures (ε—strain) Fig.3  The radial tensile E (a) and σu (b) of NNHC and CRNNHC with different temperatures (E—elastic modulus, $σu$—ultimate stress) Fig.4  The radial compression stress-strain curves of NNHC (a) and CRNNHC (b) with different temperatures Fig.5  The radial compressive E (a) and σu (b) of NNHC and CRNNHC with different temperatures Fig.6  The axial tension stress-strain curves of NNHC (a) and CRNNHC (b) with different temperatures Fig.7  Atomic snapshots of CRNNHC under axial tension at the temperature of 900 K with ε=0.084 (a) and ε=0.3 (b) Fig.8  The axial tensile E (a) and σu (b) of NNHC and CRNNHC at different temperatures Fig.9  The axial compression stress-strain curves of NNHC (a) and CRNNHC (b) with different temperatures Fig.10  The axial compressive E (a) and σu (b) of NNHC and CRNNHC at different temperatures Fig.11  Atomic snapshots of CRNNHC along different deformation directions of radial tension (a, b), radial compression (c, d), axial tension (e, f) and axial compression (g, h) under the temperature of 600 K(a) εu=0.086 (b) εu=0.586 (c) εu=0.076 (d) εu=0.436(e) εu=0.090 (f) εu=0.353 (g) εu=0.056 (h) εu=0.096