氧化铝基热挤压模具材料的研究

Study of Alumina-Based Hot-pressing Die Materials

以工业氧化铝为主要原料,滑石为烧结助剂,Y-ZrO2为增韧剂,采用真空热压烧结工艺,制备了氧化铝基热挤压模具材料。研究了热挤压模具材料的力学性能,相组成及微观结构。结果表明:当工业Al2O3含量(质量分数)为85%,滑石含量为10%,ZrO2含量为5%时,制备的氧化铝基热挤压模具材料具有良好的力学性能。抗弯强度、断裂韧度和硬度分别达到645 MPa、8.86 MPa·m1/2和9.54 GPa。添加适量的Y-ZrO2可提高材料断裂韧度。模具材料主晶相为刚玉、镁铝尖晶石以及氧化锆,显微结构中刚玉相分布均匀,镁铝尖晶石和氧化锆相分布在晶界处。

A1203-based die materials were fabricated with vacuum hot-pressing sintering technique by using talc as sintering additive and ZrO2 as flexibilizer. The mechanical properties, phase compositions and microstrucatre of the die materials were investigated. The results show that, when the contents of A1203 is 85wt%, talc is 10wt% and ZrO2 is 5wt%, the prepared A1203-based die material can achieve good mechanical properties and microstructure. The flexural strength, the fi＇acture toughness and the hardness of the die material is 660 MPa, 8.86 MPa.ml/2 and 9.54 GPa, respectively. The moderate addition of ZrOz can increase the toughness of the material, and the main phase of the die material is corundum, magnesium aluminate spinel and zirconia. The corundum phase distributes evenly, the magnesium aluminate spinel and zirconia phases scatter among the grain boundary in the microstructure.