机床用Al_2O_3/TiB_2复相陶瓷刀具材料的研究

Study on Al_2O_3/TiB_2 Compound Sintex Materials used for Machine Tool

以α-Al2O3和TiB2为主要原料,采用真空热压烧结工艺制备机床用Al2O3/TiB2复相陶瓷刀具材料。测试和分析了烧结样品的相对密度、弯曲强度、断裂韧性、硬度值、相组成以及显微结构。结果表明,当α-Al2O3添加量为75 wt%,微米TiB2添加量为20 wt%时,所制备的Al2O3/TiB2复相陶瓷刀具材料性能最佳,其相对密度值为98.8%,弯曲强度为606.25 MPa,断裂韧性为4.85 MPa·m1/2,硬度值为26.55 GPa。最佳样品的主晶相为刚玉(Al2O3)和硼化钛(TiB2),次要晶相为氧化钇(Y2O3)。

Al2O3/TiB2 compound sintex materials were fabricated with vacuum hot-pressing sintering technique by using α-Al2O3 and micro TiB2 as main materials.The properties of relative density,bending strength,fracture toughness,hardness,phase composition and microstructure were tested and analyzed.Results show that when the contents of α-Al2O3 is 75 wt%,micro TiB2 is 20 wt%,the prepared compound sintex material can achieve the best properties.The relative density,flexural strength,fracture toughness and hardness of the compound sintex material is 98.8%,606.25 MPa,4.85 MPa·m1/2 and 26.55 GPa respectively.The main phase of the best sample is corundum(Al2O3) and titanium boride(TiB2),the minor phase is yttrium oxide(Y2O3).