Electroconductive Al2O3–NbN Composites |
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Authors: | Songlin Ran Lian Gao |
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Affiliation: | State Key Lab of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 200050, China |
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Abstract: | Electroconductive Al2O3–NbN ceramic composites were prepared by hot pressing. Dense sintered bodies of ball-milled Al2O3–NbN composite powders were obtained at 1550°C and 30 MPa for 1 h under a nitrogen atmosphere. The bending strength and fracture toughness of the composites were enhanced by incorporating niobium nitride (NbN) particles into the Al2O3 matrix. The electrical resistivity of the composites decreased with increasing amount of NbN phase. For a 25 vol% NbN–Al2O3 composite, the values of bending strength, fracture toughness, Vickers hardness, and electrical resistivity were 444.2 MPa, 4.59 MPa·m1/2, 16.62 GPa, and 1.72 × 10−2Ω·cm, respectively, making the composite suitable for electrical discharge machining. |
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