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Abstract: A dense (Ti, Mo)2A1C/10wt% Al2O3 in-situ composite was successfully fabricated from powder mixtures of Ti, Al, TiC and MoO3 by reactive hot pressing sintering, and the reaction path was investigated in detail. It was found that the production of the (Ti, Mo)2A1C/10wt% Al2O3 was composed of a series of intermediate reactions: i.e., first reaction between Ti and Al forms Ti–Al intermetallics, and the thermite reaction between Al and MoO3 producing Al2O3 and Mo. Then the intermetallics and the residual Ti and Al transformed to TiAl equilibrium phase. Finally, the (Ti, Mo)2A1C/Al2O3 composite was formed by the reaction of TiAl TiC, and Mo. The Vickers hardness, flexural strength, compressive strength and fracture toughness of the composite were 4.75GPa, 458MPa, 971MPa, and 6.03MPam1/2, which are improved by 25%, 69%, 48%, and 146%, respectively, compared to the single-phase Ti2AlC. The reinforcing mechanism was also discussed. [Copyright &y& Elsevier]

Abstract: ZnO varistors were synthesized using Pr6O11 doped ZnO–Bi2O3 system as raw materials by ball milling. The effects of intensive milling on the microstructure and electrical properties of the varistors were investigated in detail. The results show the intensive milling decreases the particle size and distribution of the powders for ZnO varistors. The optimal samples obtained from the powders milled for 10h have average crystalline grain size of about 4μm and the gradient voltage of 565V/mm, the leakage current of 0.45μA, and the nonlinear coefficient of 75. [Copyright &y& Elsevier]

Abstract: (1− x)Ba(Fe0.5Nb0.5)O3–xBaTiO3 ceramics with giant dielectric constants and low losses were prepared by the conventional solid-state method. The phase structure, microstructures, electrical properties of the ceramics were investigated. The results show that the ceramics are of monoclinic structure and possess dense and fine microstructures. The incorporation of BaTiO3 can significantly reduce the dielectric loss and improve the frequency and temperature stability of the electrical properties of Ba(Fe0.5Nb0.5)O3. [Copyright &y& Elsevier]