可靠评价Y-ZrO_(2)及Y-ZrO_(2)/Al_(2)O_(3)陶瓷断裂韧性研究进展

Research Progress on Reliable Evaluation of Fracture Toughness of Y-ZrO_(2) and Y-ZrO_(2)/Al_(2)O_(3) Ceramics

Y-ZrO_(2)及Y-ZrO_(2)/Al_(2)O_(3)陶瓷材料被广泛应用于工程结构件、医疗器械、智能穿戴、电子器件等领域。断裂韧性作为评价陶瓷材料脆性断裂的重要指标,对于结构陶瓷的研发、制备、选材与设计具有决定性意义。本文基于飞秒激光改良后的单边V型切口梁法(SEVNB),回顾了Y-ZrO_(2)及Y-ZrO_(2)/Al_(2)O_(3)陶瓷材料断裂韧性评价的最新研究进展。首先对于广泛应用的Y-ZrO_(2)断裂韧性进行分析,给出Y-ZrO_(2)陶瓷断裂韧性的可靠参考值,并给出传统单边切口梁(SENB)法的经验修正公式,同时导出了不同Y2O_(3)稳定剂含量的ZrO_(2)陶瓷断裂韧性经验估算公式。通过回顾基于飞秒激光改良的SEVNB法对Y-ZrO_(2)陶瓷断裂韧性的评价,发现断裂韧性最好的2mol%Y_(2)O_(3)稳定四方多晶ZrO_(2)(2Y-TZP)陶瓷的断裂韧性为6.4MPa·m^(1/2)。其次对Y-ZrO_(2)/Al_(2)O_(3)陶瓷的断裂韧性进行了回顾,发现ZrO_(2)增韧Al_(2)O_(3)(ZTA)陶瓷随氧化锆含量的增加,其断裂韧性最多只能提升到增韧相ZrO_(2)的水平;在Y-ZrO_(2)中加入Al_(2)O_(3)获得Al_(2)O_(3)增强ZrO_(2)陶瓷(ADZ),发现随Al_(2)O_(3)加入量的增加,ADZ的韧性没有明显提升。回顾基于飞秒激光改良的SEVNB法对Y-ZrO_(2)/Al_(2)O_(3)陶瓷断裂韧性的评价,目的在于澄清ZTA陶瓷中ZrO_(2)提升Al_(2)O_(3)断裂韧性的幅度以及ADZ陶瓷中Al_(2)O_(3)提升ZrO_(2)断裂韧性的幅度。基于飞秒激光改良的SEVNB法对Y-ZrO_(2)及Y-ZrO_(2)/Al_(2)O_(3)陶瓷断裂韧性的评价,发现Y-ZrO_(2)及Y-ZrO_(2)/Al_(2)O_(3)陶瓷材料的断裂韧性依然不高,其评价值远低于铸铁的断裂韧性(~20MPa·m^(1/2)),因此Y-ZrO_(2)及Y-ZrO_(2)/Al_(2)O_(3)陶瓷的增韧依旧任重道远。本文旨在为Y-ZrO_(2)及Y-ZrO_(2)/Al_(2)O_(3)陶瓷材料断裂韧性提供参考,为Y-ZrO_(2)及Y-ZrO_(2)/Al_(2)O_(3)陶瓷材料的研发、测试、选材与设计提供依据。

Y-ZrO_(2) and Y-ZrO_(2)/Al_(2)O_(3) ceramics are widely used in engineering structural parts,medical equipment,smart wear,electronic devices and other fields.Fracture toughness,as an important index for evaluating the brittle fracture of ceramic materials,is of decisive significance for the research and development,preparation,material selection and design of structural ceramics.Based on single V-notch beam method(SEVNB)modified by femtosecond laser,this paper reviews the latest research progress on the fracture toughness of Y-ZrO_(2) and Y-ZrO_(2)/Al_(2)O_(3) ceramics.First,the fracture toughness of the widely used Y-ZrO_(2) is analyzed.The reliable reference value of the fracture toughness of Y-ZrO_(2) ceramics is summarized,and the empirical correction method of the traditional single edge notched beam(SENB)method is given.At the same time,the empirical estimation formula of the fracture toughness of zirconia ceramics doped with different yttria contents is established.Through the evaluation of the fracture toughness of zirconia ceramics based on the modified SEVNB,it is found that the fracture toughness of 2Y-TZP with the fracture toughness is optimal(only 6.4 MPa·m^(1/2)).Secondly,the fracture toughness of Y-ZrO_(2)/Al_(2)O_(3)ceramics is reviewed,and it is found that with the increase of Y-ZrO_(2) content,the fracture toughness of ZrO_(2) toughened Al_(2)O_(3)(ZTA)ceramics could only improve to the level of toughened phase Y-ZrO_(2).Y-ZrO_(2) reinforced Al_(2)O_(3) ceramics(ADZ)obtained by adding Al_(2)O_(3) to ZrO_(2) showed that the toughness of ADZ do not improve significantly with the increase of the addition amount of Al_(2)O_(3).The evaluation of the fracture toughness of Y-ZrO_(2)/Al_(2)O_(3) ceramics based on the modified SEVNB is reviewed,in order to clarify the extent of the improvement of the Al_(2)O_(3) ceramic fracture toughness by adding Y-ZrO_(2) in ZTA ceramics,and the extent of the increase of the Y-ZrO_(2) ceramics fracture toughness by adding Al_(2)O_(3)in ADZ ceramics.Based on the evaluation of the fracture toughness of Y-ZrO_(2) and Y-ZrO_(2)/Al_(2)O_(3) ceramics by the modified SEVNB,it is found that the fracture toughness of Y-ZrO_(2) and Y-ZrO_(2)/Al_(2)O_(3) ceramic materials is still small,which is far lower than that of cast iron(~20 MPa m^(1/2)),so the toughening work of Y-ZrO_(2) and Y-ZrO_(2)/Al_(2)O_(3) ceramics stll has a long way to go.The purpose of this paper is to provide a reference for the fracture toughness of Y-ZrO_(2) and Y-ZrO_(2)/Al_(2)O_(3) ceramic materials,and to provide a basis for the development,testing,material selection and design of Y-ZrO_(2) and Y-ZrO_(2)/Al_(2)O_(3) ceramic materials.