Effect of Al Content on the Microstructure and Mechanical Properties of the Sintered Fe-Mn-Al Porous Steel

Al content is of great importance for the evolution of the microstructure and compressive performance of the high-Mn and high-Al porous steels. Herein, Fe-Mn-Al porous steels with different Al contents are prepared via powder sintering at different temperatures. The results show that the main phases of the sintered samples at 640 degrees C are alpha-Fe, alpha-Mn, and Al, while a small amount of Fe2Al5 and Al8Mn5 exists in the samples with 15 and 20 wt% Al. At 1200 degrees C, the sintered sample with 5 wt% Al is composed of gamma-Fe, while those with 15 and 20 wt% Al are mainly alpha-Fe. The length of Mn depletion region and porosity of the samples increase with the increase of Al content. The largest total and open porosity are observed in the 1200 degrees C-sintered sample with 20 wt% Al, which are 63.1 and 60.7 vol%, respectively. The compressive strength decreases sharply from 770 MPa for the sample with 5 wt% Al to 7.5 MPa with 15 wt% Al, after sintering at 1200 degrees C. Ductile fracture occurs in the sample with 5 wt% Al, while brittle fracture is the main fracture mode in those with 15 and 20 wt% Al. Fe-Mn-Al porous steels with different Al contents are prepared via powder sintering at different temperatures. The phase, microstructure, and mechanical properties of the Fe-Mn-Al porous steels are systematically investigated. It is believed that the study is expected to offer significant reference for promoting the development of porous steels.image (c) 2023 WILEY-VCH GmbH