TiN-Al2O3 composite powders with different TiN contents(0,10 vol%,20 vol%,30 vol% and 40 vol%)were prepared with micrometer TiN and α-Al2O3 powder(their purities were 99%)as starting materials by wet ball milling for 5 h.TiN-Al2O3 composite were then prepared by pressing the above composite powders,drying at 200 ℃ for 12 h and firing at 1 800 ℃ for 3 h in nitrogen atmosphere in hot-pressing furnace.The influences of TiN content on mechanical properties and electrical conductivity of TiN-Al2O3 composites were studied.The results showed that the mechanical properties of the composite increased with TiN content increasing,while the resistivity of composites decreased.A composite with 40% TiN had 498 MPa bending strength,4.285 MPa·m1/2 fracture toughness,1.34×10-3Ω·cm resistivity.The SEM analysis showed that the fine TiN crystals distributed among the crystal boundary of Al2O3 matrix.They bonded together forming a net-like structure which played a role of restraining Al2O3 grains from growing up,toughening and strengthening,so the mechanical properties of TiN-Al2O3 composite were enhanced.
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