(军械工程学院先进材料研究所，石家庄050003)
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2 μm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？m0.5。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。
关键字: TiB2；超重力场；反应熔铸；刀具
（Institute of Advanced Materials, Ordnance Engineering College, Shijiazhuang 050003, China）
Abstract:Thereactive 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 TiB2 columnar 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 and 4.6 MPa？m0.5, 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.
Key words: TiB2; high gravity field; reactive casting; cutting material
