纳米MgO添加量对Al_2O_3-ZrO_2材料烧结性能的影响  

Effect of nano-MgO addition on sintering property of Al_2O_3-ZrO_2 composites

作　　者：郭会师[1] 黄宇翔 李文凤[2] 桂阳海[1] 孙雨安[1] Guo Huishi;Huang Yuxiang;Li Wenfeng;Gui Yanghai;Sun Yuan(School of Materials and Chemical Engineering, Zhengzhou University of Light Industry,Zhengzhou 450001, Henan,China)

机构地区：[1]郑州轻工业学院材料与化学工程学院,河南郑州450051 [2]河南工业大学材料科学与工程学院,河南郑州450001

出　　处：《耐火材料》2018年第6期430-433,共4页Refractories

基　　金：河南省重点科技攻关项目(182102210613);郑州轻工业学院星空众创空间孵化项目(2017ZCKJ201)

摘　　要：为了改善Al_2O_3-ZrO_2材料的烧结性能和力学性能,在Al_2O_3-ZrO_2材料配料中添加不同量(质量分数分别为0、0. 25%、0. 5%、0. 75%、1%和1. 25%)的纳米MgO,经成型、干燥、1 550℃保温3 h烧后,检测试样的烧后线变化率以及烧后试样的体积密度、显气孔率、吸水率、常温耐压强度、常温抗折强度和高温抗折强度,并进行XRD和SEM分析。结果表明:1)添加纳米MgO可促进Al_2O_3-ZrO_2材料的烧结致密化,并改善其力学性能。当纳米MgO添加量为1%(w)时,Al_2O_3-ZrO_2材料的综合性能较佳,试样的体积密度、显气孔率、吸水率和线收缩率分别为3. 34 g·cm-3、18. 7%、5. 9%和7. 6%,常温耐压强度、常温抗折强度和高温抗折强度分别为251、81. 0和24. 0 MPa。2)纳米MgO对Al_2O_3-ZrO_2材料烧结致密化和力学性能的提高归因于MgO和ZrO_2形成有限固溶体时于ZrO_2晶体中引入的缺陷促进了Zr^(4+)的扩散速率,以及亚稳态t-ZrO2发生应力诱导相变时对基体材料产生的强化作用。This paper aims at improving the sintering property and mechanical properties of Al2O3-ZrO2 composites. Different amounts of nano-MgO( 0,0. 25%,0. 5%,0. 75%,1% and 1. 25% by mass,the same hereinafter) were added into the starting materials for preparing Al2O3-ZrO2 composites. After shaping,drying,and firing at 1 550 ℃ for 3 h,the Al2O3-ZrO2 composites were tested in terms of bulk density,apparent porosity,water absorption,cold crushing strength,cold modulus of rupture as well as hot modulus of rupture. XRD and SEM analyses were carried out as well. Results show that( 1) the addition of nano-MgO enhances the sintering densification and mechanical properties of Al2O3-ZrO2 composites; with nano-MgO addition of 1%,Al2O3-ZrO2 composites have excellent comprehensive properties,the values of the bulk density,apparent porosity,water absorption and linear shrinkage ratio are 3. 34 g·cm-3,18. 7%,5. 9% and7. 6%,respectively; while the values of cold crushing strength,cold modulus of rupture and hot modulus of rupture are 251 MPa,81. 0 MPa and 24. 0 MPa,respectively;( 2) the enhancement effect of nano-MgO for sintering densification and mechanical properties of Al2O3-ZrO2 composites can be attributed to the introduction of defects in ZrO2 crystals when MgO and ZrO2 form limited solid solution which can improve the diffusion rate of Zr4+ and the matrix strengthening effect generated by the phase change of metastable t-ZrO2 under the action of stress.

关 键 词：纳米MgO Al2O3-ZrO2材料 固溶体 烧结 力学性能 

分 类 号：TM175.79[电气工程—电工理论与新技术]