The Effect of in-situ Formation of Al2O3 or Fe3AlC on the Structural and Mechanical Properties of FeAl Intermetallic Alloys

Abstract

The effect of in-situ formation of reinforcing phase on the mechanical properties of FeAl intermetallic alloy was studied. The in-situ FeAl composites containing Al2O3 or Fe3AlC were fabricated by mechanical alloying of elemental powders and mill scale powder followed by vacuum hot pressing. The starting materials were mixed in the appropriate ratio to synthesize 10vol% of the reinforcing phase. FeAl+Al2O3 and FeAl+Fe3AlC alloys showed high hardness value of HV813 and HV524, respectively. The effect of testing temperature on the 0.2% proof stress was evaluated at the temperature range from room to 1273K under compression. FeAl+Al2O3 and FeAl+Fe3AlC alloy showed proof stress of 2240MPa and 1380MPa at room temperature, respectively. At higher temperatures above 773K the proof stress decreased rapidly. The FeAl base in-situ composites including Fe3AlC or Al2O3 showed the high stress exponent and activation energy in the temperatures range of 1073-1273K.