Effect of LaMgAl₁₁O₁₉ addition and temperature on the mechanical properties of Al₂O₃-based ceramics

详细信息    查看全文

• 作者：Hao Tang ; Minghao Fang ; ^{fmh@cugb.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Chao Tang ; Zhaohui Huang ; ^{huang118@cugb.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Haitao Liu ; Hekai Zhu ; Yangai Liu ; Xiaowen Wu
• 关键词：Al2O3 ; LaMgAl11O19 platelets ; High-temperature mechanical properties ; Microstructure
• 刊名：Materials Science & Engineering A
• 出版年：2016
• 出版时间：8 February 2016
• 年：2016
• 卷：655
• 期：Complete
• 页码：160-167
• 全文大小：2180 K

文摘

In this study, the effect of the LaMgAl₁₁O₁₉ content on the mechanical properties of pressureless sintered Al₂O₃–LaMgAl₁₁O₁₉ composites, including room-temperature fracture toughness and flexural strength from room temperature to 1400 °C, was systematically investigated. Results indicated that Al₂O₃–LaMgAl₁₁O₁₉ ceramics exhibit enhanced mechanical properties as compared with those of monolithic Al₂O₃ ceramics both at room and elevated temperatures, with the maximum fracture toughness and flexural strength values of 4.88 MPa m^1/2 and 472.8 MPa at room temperature, respectively. The flexural strength of Al₂O₃–LaMgAl₁₁O₁₉ ceramics gradually decreased with increasing test temperature below 1000 °C and sharply decreased thereafter. The improved mechanical properties of Al₂O₃–LaMgAl₁₁O₁₉ composites at ambient temperature were primarily attributed to the combination of crack deflection and bridging of LaMgAl₁₁O₁₉ platelets, while under elevated temperatures, the presence of LaMgAl₁₁O₁₉ platelets also played a crucial role in effectively hindering the grain boundaries sliding, thereby endowing superior bending strength to the composites.