微波烧结ZrO_(2(n))增韧Al_2O_3复合陶瓷组织与性能研究

Study on Microwave Sintering Structure and Properties of ZrO_(2(n))-Al_2O_3 Composite Ceramics

文章采用微波烧结制备ZrO2/A l2O3复合陶瓷,探讨了纳米ZrO2对A l2O3陶瓷的烧结、力学性能和显微结构的影响。结果表明:纳米ZrO2的加入会对A l2O3陶瓷的显微结构产生影响,ZrO2颗粒以"晶内型"和晶界型两种形式存在,ZrO2的相组成与其含量有关。合理的实验配方及制备工艺有利于ZrO2以四方亚稳相存在。ZrO2含量为15vol%时,ZrO2全部由四方相组成,有利于应力诱导相变增韧,该ZrO2/A l2O3复合陶瓷的硬度、断裂韧性和抗弯强度分别为13350MPa、6.41MPa.m1/2和502MPa。ZrO2/A l2O3复合陶瓷増韧机制为应力诱导相变增韧、内晶型结构增韧和微裂纹増韧。

ZrO2/Al2O3 composite ceramics were made by microwave sintering method. The influences of nano -ZrO2 on the sintering, mechanical properties and microstructure of Al2O3 ceramics were discussed. The results show that the addition of ZrO2 will affect the microstructure of Al2O3 ceramics, ZrO2 particles coexist in intragranular and grain boundary, the phase of ZrO2 are related to its content. A rational experimental prescription and preparation technology are propitious to ZrO2 coexisting t - ZrO2. When the content of ZrO2 is 15vo1% , ZrO2 all exist in the form of t - ZrO2 , in favor of the stress induced phase transformation, its hardness, fracture toughness and flexural strength are 13350MPa ,6.41 MPa · m^1/2 and 502MPa. ZrO2/Al2O3 composite ceramics are toughened mainly by the stress induced phase transformation, Microcrack and the intragranular formation of zircoina.