THE EFFECT OF ALUMINA NANOPARTICLES ADDITION ON HIGH-TEMPERATURE WEAR BEHAVIOR OF INTERMETALLIC IRON ALUMINIDE PRODUCED BY THE SPARK PLASMA SINTERING PROCESS

The pure iron and aluminum powders were milled with 3 wt.% and 7 wt.% of alumina nanoparticles in planetary ball mill in order to produce iron aluminide by mechanical alloying technique. The resulting powder mixture was sintered after the formation of iron aluminide by spark plasma sintering (SPS) method to achieve specimens with the highest densification. SPS technique was utilized on specimens under the condition of 40 MPa pressure at 950 degrees C for 5 min. The microstructures were analyzed after sintering using scanning electron microscopy and EDS analysis. The results indicated that the aluminide iron phase has been produced at high purity. The sintered specimens were treated under hardness and density tests, and it was characterized that the specimen included 3 wt.% of alumina nanoparticles had the highest microhardness. Likewise, it was revealed that the unreinforced sample had a maximum relative density. The wear behavior of specimens was performed at 600 degrees C. The results of weight loss showed after 1000 m of wear test, the weight loss of unreinforced specimen was reduced up to 0.21 g while the specimen with 3 wt.% of alumina nanoparticle indicated the lowest weight loss about 0.02 g. The worn surfaces were evaluated by scanning electron microscopy which indicated that the main wear mechanism at high temperature included adhesive wear and delamination.