Y_2O_3添加量对Al_2O_3/ZrO_2复合材料烧结行为和热机械性能的影响

Effects of Y_2O_3 Contents on Sintering Behavior and Thermo-mechanical Properties of Al_2O_3/ZrO_2 Composites

研究了Y_2O_3添加量对Al_2O_3/ZrO_2复合材料烧结行为和热机械性能(高温抗折强度和抗热震性)的影响,并研究了这些性能与物相组成和显微结构间的关系。结果表明:Y_2O_3在Al_2O_3/ZrO_2复合材料中起稳定ZrO_2晶型、改善烧结致密化、提高高温抗折强度和抗热震性的作用。当Y_2O_3添加量为1%时,试样的烧结性能和高温抗折强度较佳,体积密度、显气孔率和线收缩率分别为3.27 g/cm3、21.95%和7.43%,高温抗折强度达29 MPa;抗热震性则在Y_2O_3添加量为0.5%时较佳,其残余强度保持率为71%。Y_2O_3对Al_2O_3/ZrO_2复合材料烧结性能和热机械性能的影响与Y_2O_3/ZrO_2固溶体的形成、Al_2O_3和ZrO_2晶体间的结合程度及试样中微裂纹含量密切相关。

Effects of Y2O3 contents on sintering behavior and thermo-mechanical properties （ hot modulus of rupture （HMOR） and thermal shock resistance （TSR）） of Al2O3/ZrO2 composites, as well as their relationships with phase composition and microstructure have been investigated. It is found that Y2O3 not only stabilizes the tetragonal phase of ZrO2, but also promotes the sintering behavior and increases HMOR and TSR of Al2O3/ZrO2 composites. When Y2O3 addition is up to 1% , the sample shows excellent sintering behavior and has higer HMOR, values of bulk density, apparent porosity and shrinkage ratio are 3.27 g/cm^3, 21.95% and 7.43% , respectively, and the value of HMOR is 29 MPa. While the TSR exhibits excellent performance when Y2O3 addition reaches 0.5% , the residual strength ratio is 71%. These changes have close relationships with the formation of Y2O3/ZrO2 solid solution, degree of contact between Al2O3 and ZrO2 crystals, microcraek contents in samples.