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.