Research on high-temperature compression and creep behavior of porous Cu–Ni–Cr alloy for molten carbonate fuel cell anodes

Abstract

The effect of porosity on high temperature compression and creep behavior of porous Cu alloy for the new molten carbonate fuel cell anodes was examined. Optical microscopy and scanning electron microscopy were used to investigate and analyze the details of the microstructure and surface deformation. Compression creep tests were utilized to evaluate the mechanical properties of the alloy at 650°C. The compression strength, elastic modulus, and yield stress all increased with the decrease in porosity. Under the same creep stress, the materials with higher porosity exhibited inferior creep resistance and higher steadystate creep rate. The creep behavior has been classified in terms of two stages. The first stage relates to grain rearrangement which results from the destruction of large pores by the applied load. In the second stage, small pores are collapsed by a subsequent sintering process under the load. The main deformation mechanism consists in that several deformation bands generate sequentially under the perpendicular loading, and in these deformation bands the pores are deformed by flattering and collapsing sequentially. On the other hand, the shape of a pore has a severe influence on the creep resistance of the material, i.e. every increase of pore size corresponds to a decrease in creep resistance.

Study on Tensile Creep Behavior of 12Cr1MoV Alloy Steel under High-Temperature Alkali Metal Salt Environment for Solar Thermal Power Generation

“…A large number of studies have shown that the stress exponent is directly related to the creep deformation mechanism. The material deformation is controlled by the diffusion creep mechanism at n = 1, the material deformation is a dislocation slip mechanism at n = 3, the material deformation is dislocation climb mechanism in high-temperature environment at n = 5, and the material deformation is the dislocation climb mechanism at low temperature at n = 7 [9]. The stress exponent of this experiment is close to 1 in the above creep deformation mechanism.…”

“…The creep properties of salt-coated alloy are available in literatures. Most studies mainly focus on the influence of a single saline environment on creep rupture life, deformation mechanisms of alloy, and creep properties [9]. Various fac-tors that reduce the creep life of alloys by thermal corrosion, such as the generation and propagation of surface cracks, have been confirmed by previous studies.…”

Ni-Al Bronze in Molten Carbonate Manufactured by LPBF: Effect of Porosity Design on Mechanical Properties and Oxidation

“…The standard porosity of anodes varies between 50 and 65%, with a pore size of around 2–3 µm [ 6 , 9 ]. Anodes are affected by compressive and thermal stresses during the operation of MCFCs, which favor the creep deformation that decreases their porosity and electrochemical activity [ 10 , 11 ]. Even though this alloy has been shown to be ideal as an anode, some authors found that the loss of porosity during the MCFC’s operation influences the catalytic performance and efficiency of anodes [ 10 , 12 , 13 ].…”

Effect of Laser Shock Processing and Aluminizing on Microstructure and High-Temperature Creep Properties of 321 Stainless Steel for Solar Thermal Power Generation

“…Therefore, it is vitally significant to improve the power generation efficiency, reduce the cost, and increase service life of the solar thermal power generation system. However, as the key component of CSP, the heat exchange tube should be paid more attention [3][4][5][6].…”