B2-structured Fe3Al alloy manufactured by laser powder bed fusion: Processing, microstructure and mechanical performance

Prealloyed Fe3Al was successfully manufactured by laser powder bed fusion. The best set of process parameters led to parts with a relative density of 99.5 %, a surface roughness, Sa, of 31.5 +/- 5.6 mu m and a hardness of 319 +/- 14 HV0.1. Its microstructure as well as its mechanical properties at room and high temperatures were analyzed. The results of the chemical composition showed minor variations in aluminum content oscillating between 21 and 28 at.% along the melt pool. Additionally, elongated grains were observed to grow parallel to the building direction, as well as the development of a weak {001} texture along the building direction. The mechanical properties were influenced by the temperature. Compression tests showed a loss in strength with the increase in temperature, from a yield strength of 621 +/- 40 MPa at room temperature to 89 +/- 20 MPa at 650 degrees C. Recip-rocating sliding wear tests showed that fragmentation of the intermetallic at room temperature occurs, whereas plastic deformation dominated at higher temperatures. For all temperatures, tribochemical wear was also present due to the oxidation of wear debris.

Automated summary

Prealloyed Fe3Al with high density, good surface quality, and suitable mechanical properties was successfully manufactured using laser powder bed fusion. The presence of minor variations in aluminum content along the melt pool and the development of a weak texture along the building direction were observed in the microstructure. The mechanical properties were found to be temperature-dependent, with a significant loss in strength at higher temperatures due to plastic deformation and tribochemical wear.