中文摘要：

通过超重力场反应熔铸合成TiB2基复相陶瓷刀具材料,研究材料的物相组成、组织结构及力学性能,探讨材料中典型组织的形成过程。结果表明：反应产物由TiB2与TiC两相构成,尺寸约为2μm的TiB2柱状晶构成陶瓷基体,TiC晶粒不规则地分布于TiB2晶粒之间,二者结合紧密,呈现出典型的凝固组织特征。所得反应产物的相对密度为93.2%,维氏显微硬度值为21.4 GPa,抗弯强度为258 MPa,断裂韧性为4.6 MPa·m~（0.5）。分析认为超重力场促进Ti-B-C中间熔体的生成,是合成TiB2基复相陶瓷的关键。

英文摘要：

The reactive casting processing was used to synthesize the TiB2-based multiphase ceramics for cutting materials in high-gravity field.The phase composition,microstructures,mechanical properties and forming mechanism of the products were studied.The results show that the products contain TiB2 and TiC phases;the matrix consists of TiB2columnar crystals in size range of 2 μm which approximately distribute between the irregular TiC crystals regularly.The ceramics are presented with typical solidified morphologies,the TiB2 crystals are well-bonded with TiC.The relative density,Vickers micro-hardness,bending strength and fracture toughness of products are 93.2%,21.4 GPa,258 MPa and4.6 MPa·m~（0.5）,respectively.It is proposed that the formation of Ti-B-C intermediate melt promoted by high gravity field is the key factor for fabricating multiphase TiB2-based ceramics.