(軍械工程學院先進材料研究所，石家莊050003)
摘 要: 通過超重力場反應(yīng)熔鑄合成TiB2基復相陶瓷刀具材料，研究材料的物相組成、組織結(jié)構(gòu)及力學性能，探討材料中典型組織的形成過程。結(jié)果表明：反應(yīng)產(chǎn)物由TiB2與TiC兩相構(gòu)成，尺寸約為2 μm的TiB2柱狀晶構(gòu)成陶瓷基體，TiC晶粒不規(guī)則地分布于TiB2晶粒之間，二者結(jié)合緊密，呈現(xiàn)出典型的凝固組織特征。所得反應(yīng)產(chǎn)物的相對密度為93.2%，維氏顯微硬度值為21.4 GPa，抗彎強度為258 MPa，斷裂韌性為4.6 MPa？m0.5。分析認為超重力場促進Ti-B-C中間熔體的生成，是合成TiB2基復相陶瓷的關(guān)鍵。
關(guān)鍵字: TiB2；超重力場；反應(yīng)熔鑄；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
