• Journal of the Korean Electrochemical Society
• /
• v.9 no.3
• /
• pp.124-131
• /
• 2006

For commercialization of molten carbonate fuel cell (MCFC), it has some problems to be overcome such as decrease of porosity and thickness of the anode under the operating condition (at $650^{\circ}C$ and working pressure of more than 2 $kg_f/cm^2$). Recently, Ni-Al alloy anode has been proposed to replace the conventional Ni-Cr anode as an alternative material to resist a creep and inhibit the sintering. The objective of this research is to sinter the green sheet of Ni-Al alloy anode during single cell pre-treatment process, which has several advantages like cost down and simplification of manufacturing process. However, the Ni-Al alloy anode prepared with a conventional pre-treatment process showed the phase separation of Ni-Al alloy and formation of micropore(${\leqq}0.4{\mu}m$), resulting in low creep resistance and high electrolyte re-distribution. In order to prevent the Ni-Al alloy anode from phase-separating, nitrogen gas was used in the process of pre-treatment. Introducing the nitrogen, the phase separation from Ni-Al alloy into nickel and alumina was minimized and increased creep resistance. However, there was some micropore formation on the surface of Ni-Al alloy anode during the cell operation due to creation of lithium aluminate. Addition of more amount of electrolyte into a cell, especially at cathode, made the cell performance stable for 2,000 hrs. Consequently, it was possible to make the Ni-Al alloy anode with good creep resistance by the modified in-situ sintering technique.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.2 no.1
• /
• pp.67-77
• /
• 1998

Homogeneous liquids of Ni-21.5Nb-2.5Al and Ni-23.3Nb eutectic superalloys were solidified into Ni/$Ni_3$Al-$Ni_3$Nb(${\gamma}$/${\gamma}$'-${\delta}$)and Ni-Ni/$Ni_3$Nb(${\gamma}$-${\delta}$) phase by directional solidification and the effect of interlamellar spacing on microsturctural stability at high temperatures, hardness variation with growth rate was studied. The interlamellar spacing(${\lambda}$) in the eutectics was varied with the growth rate(R), corresponding to "${\lambda}^2$R ＝Constant" relationship. Isothermal heat treatments of the eutectics used in this study, provided the microstructural stability improvement at hight temperature as the interlamellar spacing increases. It was also seen that the hardness improvement is made with the growth raterowth rate

• Korean Journal of Materials Research
• /
• v.12 no.11
• /
• pp.845-849
• /
• 2002

Alloys of $Fe_3$Al, $Fe_3$Al-6Cr, $Fe_3$Al-4Cr-1Mo, $Ni_3$Al, and $Ni_3$Al-2.8Cr were oxidized at $1000^{\circ}C$ in air, and the oxide scales formed were studied using XRD. SEM, EPMA, and TEM. The oxide scales that formed on $Fe_3$Al-based alloys consisted primarily of $\alpha$-$Al_2$$O_3$ containing a small amount of dissolved Fe and Cr ions, whereas those that formed on $Ni_3$Al-based alloys consisted primarily of $\alpha$-$Al_2$$O_3$, together with a small amount of $NiAl_2$$O_4$, NiO and dissolved Cr ions. For the entire alloys tested, nonadherent oxide scales formed, and voids were inevitably existed at the scale-matrix interface.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2002.05a
• /
• pp.79-79
• /
• 2002

• Proceedings of the KWS Conference
• /
• 1997.05a
• /
• pp.48-50
• /
• 1997

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2000.11a
• /
• pp.35-35
• /
• 2000

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2000.05a
• /
• pp.41-42
• /
• 2000

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2000.04a
• /
• pp.46-46
• /
• 2000

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2005.11a
• /
• pp.22-22
• /
• 2005

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 1993.11a
• /
• pp.52-53
• /
• 1993