| In this work,the TiN-Al2O3 composites were preparated through the with the in-situ reaction sintering method with micro-powder of Ti and Al as additives respectively. The mechanical properties, electrical properties and microstructures were tested.The results show that:All the micro-powder of Ti in the samples were trasformed into nitrides after the in-situ reaction sintering which were uniformly distributed in the composites.The sintering temperature for the composites were decreased significantly through the in-situ reaction sintering.The rupture strength, the fracture toughness and the hardness of the composites were increased as the sintering temperature is rised. While at each sintering temperature,the rupture strength, the fracture toughness and the hardness of the composites were decreased with the increased Ti content of the sample which is resulted from the volume expand caused by the nitridation of the micro-powder of Ti bringing forth the destroy of the surround structure.The composite with the best properties with 206MPa rupture strength,1021 HV,3.95 MPa-m fracture toughness and 2.98×109Ω·cm resistivity was obtained at the sintering temperature of 1550℃for 3 hours from the sample with 5wt% initial content of Ti.Dense TiN-Al2O3 composite cannot be obtained from the samples with the micron-powder of Al after sintered at 1400℃1500℃1600℃and 1700℃for 3 hours respectively because of the poor wettability of AlN to TiN and Al2O3 and the large volume expand resulted from the nitridation of micron-powder of Al.It is shown that some Al powder remained in the sample after the in-situ reaction sintering at 1400℃ for 3 hours but no Al powder remained in the sample after the course at 1500℃and 1600℃for 3 hours respectively. AlON was generated in the samples with high content of micro-powder of Al after the course at 1700℃for 3 hours. |
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