The Fe-Ni-Mo-C-Cu (Q61) composite materials reinforced by different contents of microscaled alumina particles were prepared by powder forging and the microstructures and properties of the composites in the quenched and tempered states were investigated. The Al2O3 particles were distributed homogeneously in the matrix when its amount is 0.15 wt.%. Resultantly, the hardness and yield strength of the tempered composite were increased from HRC 38 and 1106 MPa to HRC 39.8 and 1121 MPa, respectively, while the elongation was decreased from 12% to 6.5%, all in comparison with the single Q61 under the same state. Correspondingly after quenching, the hardness was enhanced from HRC 61.5 to HRC 63.2 and the wear rate was reduced from 5.27×10-6 mm3·m-1·N-1 to 3.08×10-6 mm3·m-1·N-1, lower than that of the typical gear material 40Cr (3.24×10-6 mm3·m-1·N-1). However, the alumina was aggregated gradually to a great extent when the addition content was further improved. Though the yield strength is still improved, the plasticity is reduced significantly for the tempered materials, and the wear rate was greatly increased for the quenched counterparts, showing degraded wear resistance. Overall, the composite with 0.15 wt. % alumina can achieve a better combination of comprehensive mechanical properties and good wear resistance in the tempered and quenched states, respectively. This work can provide useful guidance for the microstructure and property manipulation and the industrial applications for this series of materials prepared by powder forging.
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