| Title |
Research Paper - Environment : The Effect of the Zr Addition on the Oxidation Behavior of Fe - Aluminide Intermetallic Compounds |
| Authors |
최송천(S . C . Choi); 김승호(S . H . Kim); 이동복(D . B . Lee); 박현순(H . S . Park) |
| Abstract |
The oxidation behaviors of Fe₃Al+2.0Cr+0.04B and Fe₃Al+1.87Cr+0.04B+0.14Zr(at.%) alloys were studied in 1 atm of air at 800, 1000 and 1200℃. Though the isothermal oxidation behavior of these alloys was relatively similar, the Zr-added alloy displayed better cyclic oxidation behavior with negligible scale spallations compared with the Zr-free alloy, especially at temperatures above 1000℃. The effects of Zr are (i) to improve the adherence of protective layer of Al₂O₃ scale by mechanically keying the scale, (ii) to facilitate the rapid formation of the scale by providing heterogeneous nucleation sites, (iii) to act as a vacancy sink by vacancy accomodation and (iv) to relieve the growth stress by decreasing Al^(3-) counter diffusion and by preventing the formation of new oxides within the pre-existing oxide. |