Thermal plasma jet approach towards the controllable preparation of Al-Fe alloys with high Fe content and spherical second phase

Al-Fe alloys with high Fe content and spherical Al3Fe phase have been successfully fabricated via the thermal plasma jet (TPJ) approach. The main size of spherical Al3Fe phase ranges from 10-15 μm and the minimum value is below 8 μm, and the average size of irregular Al3Fe phase typically bellow 20 μm. In this work, Fe content of the as-fabricated Al-Fe alloys are 5 wt.%, 10 wt.% and 15 wt.%, respectively. Microstructure characterization indicated that almost all of the Al3Fe phase distributed evenly on the Al matrix. A possible formation mechanism of spherical Al3Fe prepared via TPJ approach was tentatively proposed after investigating two different conditions with and without plasma arc heating. Meanwhile, we found that the morphology of Al3Fe could be modified via plasma arc in the preparation process.