Fe-Cr-Co permanent magnet alloys containing Nb and Al

Abstract

The vertical section of the Fe-Cr-Co system at 15 wt%Co, 1 wt%Nb and 1 wt%Al was constructed. The extention of the α phase region of the system was sufficient enough to allow for the solution treatment of the alloys at 25∼30 wt%Cr content at any temperature above the α <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</inf> +α <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> miscibility gap. After step-tempering, their magnetic properties were given as Br = 11.5∼13 KG, Hc = 500∼600 Oe and (BH)max = 4∼5 MGOe. These values were also achieved by continuous cooling from α phase region. The addition of Nb and Al to Fe-Cr-Co system will facilitate a practical manufacturing for producing Fe-Cr-Co permanent magnets.