基于梯度结构的Al_(2)O_(3)/ZrO_(2)陶瓷刀具材料的制备及其力学性能  

Preparation and Mechanics Properties of Al_2O_3/ZrO_2 Ceramic Tool Materials Based on Gradient Structure

作　　者：周后明[1] 陈皓月 李神贵 ZHOU Houming;CHEN Haoyue;LI Shengui(School of Mechanical Engineering, Xiangtan University)

机构地区：[1]湘潭大学机械工程与力学学院,湘潭411105

出　　处：《中国机械工程》2023年第10期1199-1207,共9页China Mechanical Engineering

基　　金：湖南省自然科学基金(2020JJ4585);湖南省教育厅基金(21A0117);广东省科技厅项目(2020B1212060067)。

摘　　要：采用真空热压烧结方式制备了Al_(2)O_(3)/ZrO_(2)梯度复合陶瓷刀具材料,并对ZrO_(2)含量及梯度结构层厚比进行了优化。层厚比为2.0的AZE20梯度复合陶瓷刀具材料维氏硬度为(18.7±0.33) GPa,抗弯强度为(937±28.5) MPa,断裂韧性为(8.2±0.32) MPa·m^(1/2),相比最佳ZrO_(2)含量的均质复合陶瓷刀具材料AZ20,维氏硬度、抗弯强度和断裂韧性分别增加了22%、37.8%和43.8%。梯度结构的设计使表层形成残余压应力,晶粒得到一定程度的细化,更多的ZrO_(2)晶粒因残余压应力尺寸稳定在t相ZrO_(2)晶粒尺寸。在复合材料断口形貌中发现,其断裂方式为表层穿晶断裂和中间层沿晶断裂的结合,这种混合断裂方式使刀具整体力学性能得到提高。Al_2O_3/ZrO_2 gradient composite ceramic tool material was prepared by vacuum hot pressing sintering,and the content of ZrO_2 and the layer thickness ratio of gradient structure were optimized.The Vickers hardness,flexural strength and fracture toughness of AZE20 gradient composite ceramic tool material with layer thickness ratio of 2.0 are(18.7±0.33) GPa,(937±28.5) MPa and(8.2±0.32) MPa·m~(1/2) respectively.Compared with the homogeneous ceramic tool material AZ20 with the best ZrO_(2 )content,the Vickers hardness,flexural strength and fracture toughness are increased by 22%,37.8% and 43.8%,respectively.The design of the gradient structure makes the surface layer form the residual compressive stress,the grain is refined to a certain extent,and more ZrO_2 grains are stable in the T-phase ZrO_2 grain size due to the size of the residual compressive stress.It is found that the fracture mode of the composite is the combination of the transgranular fracture of the surface layer and the intergranular fracture of the middle layer,and this hybrid fracture mode improves the overall mechanics properties.

关 键 词：陶瓷刀具材料 梯度结构 残余压应力 混合断裂 力学性能 

分 类 号：TQ174[化学工程—陶瓷工业]