Iron coated chromium powder and SOFC IC made therefrom
View Patent ↗A component, such as a SOFC interconnect, and methods of making the component are provided using various chromium powders, including powder particles with a chromium core covered with an iron shell, a pre-alloyed Cr—Fe powder or a chromium powder produced by hydrogen reduction with hydrogen.
1. A method of manufacturing an interconnect, comprising:
providing a pre-alloyed Cr—Fe powder made from a melt containing iron and chromium recovered from an aluminothermic process;
compacting the pre-alloyed Cr—Fe powder in a die to form the interconnect; and
sintering the compacted powder at a temperature between 1300-1500° C. for 5-30 hours.
2. The method of claim 1 , further comprising mixing the pre-alloyed Cr—Fe powder with a second powder comprising at least one of Co, Ni, Cu, Fe, Y, or Cr.
3. The method of claim 1 , wherein the interconnect comprises 1-10 wt % iron and balance chromium and the interconnect is configured for a solid oxide fuel cell stack.
4. The method of claim 1 , wherein the step of sintering the compacted powder comprises sintering the compacted powder in an atmosphere comprising hydrogen or an inert gas after compacting.
5. The method of claim 1 , wherein the interconnect has a substantially homogeneous distribution of iron and a substantially homogeneous distribution of coefficient of thermal expansion throughout the interconnect.
6. The method of claim 1 , wherein the pre-alloyed Cr—Fe powder is made by adding iron to a chromium melt recovered from the aluminothermic process to form the melt containing iron and chromium recovered from the aluminothermic process, and atomizing the melt.