论文部分内容阅读
Ｃｅ－ＴＺＰ（氧化铈稳定四方氧化锆多晶）材料由于剧烈的自催化相变易于产生低应力屈服，并在裂纹尖端形成狭长形相变区从而使相变增韧的效果得不到充分的发挥．本工作从改变Ｃｅ－ＴＺＰ材料的微观结构以改变其相变屈服和相变增韧行为的目标出发，在Ｃｅ－ＴＺＰ中引入了层、片状Ａｌ２Ｏ３制成Ｃｅ－ＴＺＰ／Ａｌ２Ｏ３复合材料．研究了Ｃｅ－ＴＺＰ直通切口梁试样在三点弯曲试验条件下的自催化相变特征和力学行为，以及Ａｌ２Ｏ３层片在抑制自催化相变和改变其相变增韧效果中所起的作用．研究表明，Ｃｅ－ＴＺＰ切口样在切口端部形成树根状自催化相变区，其分支和扩展与裂纹的产生与扩展相伴随；Ｃｅ－ＴＺＰ／Ａｌ２Ｏ３层片状复合材料中未看到相变区增宽现象，但Ａｌ２Ｏ３层片的存在抑制了自催化相变，使材料的相变塑性显著降低而强度显著提高，并使断裂韧性获得一定的改善．
Ce-TZP (ceria-stabilized tetragonal zirconia polycrystal) materials tend to yield low-stress yielding due to severe autocatalytic phase transformation and form an elongated transition phase at the crack tip so that the effect of phase transformation toughening is not sufficient Play In this work, Ce-TZP / Al 2 O 3 composites were introduced into Ce-TZP by changing the microstructure of Ce-TZP material and changing its phase transformation yielding and phase transformation toughening behavior. The autocatalytic phase transition behavior and mechanical behavior of Ce-TZP through-notch beam specimens under three-point bending test and the role of Al2O3 sheet in inhibiting autocatalytic phase transition and changing its phase transformation toughening effect . The results show that the root-shaped autocatalytic phase transition region is formed at the notch end of Ce-TZP, and the branching and propagation are accompanied by the generation and propagation of cracks. Ce-TZP / Al 2 O 3 flake composites show no phase However, the existence of Al2O3 layer inhibits the autocatalytic phase transformation, significantly reduces the phase transformation plasticity and the strength of the material, and improves the fracture toughness to a certain extent.