Preparation and Mechanical Properties of FeMo-Al_2O_3 Composite Ceramics

FeMo-Al2O3 composite ceramics were prepared at 1600 ℃ holding for 2 h by pressureless sintered in reducing atmosphere,using FeMo70 alloy and α-Al2O3 as starting materials.The effect of addition of FeMo70 alloy on phase composition and the mechanical properties of FeMo-Al2O3 composite ceramics were studied.Results showed that phases of samples were mainly α-Al2O3,Fe2Mo and Fe6Mo7N2.The average grain size of Al2O3 matrix increased from 4 μm to about 15 μm when adding FeMo70 alloy.Rockwell hardness and fracture toughness of increased first and then decreased with the increasing amount of FeMo70 alloy.When 13wt% FeMo-Al2O3 composite ceramics of FeMo70 alloy were added,Rockwell hardness(HRA)and fracture toughness(KIC)of composite ceramics reached a maximum value of 88.3 and 3.7 MPa·m1/2,respectively.