Er3+掺杂ZrO2(YSZ)透明陶瓷强韧化机制及光学性能研究

ZrO2(YSZ) and Er3+:ZrO2 (YSZ) nanopowers with high sintering activity were prepared by mechanochemical method, and high strength-toughness and high transparency nano ZrO2(YSZ) and Er3+:ZrO2 (YSZ) transparent ceramics were prepared by microwave sintering under relatively low temperature. The microstructural formation mechanism and regularity of the high strength-toughness and high transparency transparent ceramics were explored through studying on the relationship among the composition, microstructure and properties of materials. Expecially, Y2O3 doping, the densification mechanism and strength-toughening mechanism (such as refined crystalline strengthening, transformation toughening and microcrack toughening, etc.) of the preparation of ZrO2 transparent ceramics by microwave sintering were investigated. Moreover, the fine particle light scattering model of the transparent ceramics was established and up-conversion luminescence mechanism of the Er3+:ZrO2 (YSZ) transparent ceramics was researched. The reseach of this project is of benefit to further deeply know and understand a series of scientific problems of the transparent ceramics, such as the design, preparation, test and mechanism research, etc, and lay a solid foundation of theory and practice for developing a microwave sintering low temperature preparation techology of high strength-toughness and high transparency nano ZrO2(YSZ) transparent ceramics and realizing the up-conversion laser output of the Er3+:ZrO2 (YSZ) transparent ceramics.

本研究以ZrO2为基质，通过机械力化学法制备ZrO2(YSZ)和Er3+: ZrO2 (YSZ)高烧结活性纳米粉，在较低温度下微波烧结制备高强韧性、高透光率纳米ZrO2（YSZ)和Er3+: ZrO2 (YSZ)透明陶瓷。通过对材料组成－结构－性能相互关系研究，探索高强韧性、高透光率透明陶瓷微结构形成机制与规律并实现精确控制，重点探索Y2O3掺杂和微波烧结ZrO2透明陶瓷致密化机制和细晶强化、相变增韧、微裂纹增韧等强韧化机理，建立透明陶瓷细颗粒光线散射模型，探索Er3+: ZrO2 (YSZ)透明陶瓷的上转换发光机理。本项目研究将有助于进一步深入认识和理解透明陶瓷的设计、制备、测试和机理研究等一系列科学问题，为发展一种高强韧、高透光率纳米ZrO2 (YSZ)透明陶瓷微波烧结低温制备技术并实现Er3+:ZrO2 (YSZ)透明陶瓷上转换激光输出奠定坚实的理论和实践基础。

通过化学共沉淀法制备稀土离子Er3+和Ho3 +/Yb3 +掺杂3YSZ和8YSZ高烧结活性纳米粉，粉体压制后微波烧结制备高强韧性、高透光率稀土离子掺杂的YSZ透明陶瓷。重点研究了YSZ透明陶瓷微波烧结工艺及强韧化机理、Er3+:YSZ纳米粉的制备及发光性能机理、Er3+:YSZ透明陶瓷制备及发光机理、Ho3+/Yb3+:YSZ 纳米粉体制备及发光机理等四方面内容。.研究表明掺杂Y2O3的ZrO2(8YSZ)透明陶瓷微波烧结温度1400℃比传统烧结的1600℃降低200℃，微波烧结制备纳米ZrO2(YSZ)和Er3+:ZrO2(YSZ)透明陶瓷材料具有较高的透光率、抗弯强度和断裂韧性，如ZrO2(8YSZ)和Er3+: 8YSZ可见光透光率≥ 71 ％，红外透光率≥ 80 ％；HV≥14.1Gpa，抗弯强度σbb≥467MPa，断裂韧性K1C≥3.52MPa.m1/2。其高强韧性、高透光率主要是纳米粉具有较高的烧结活性，同时微波烧结时材料内部分子或离子的动能增加，烧结活化能降低，扩散系数提高，因而烧结速度快、温度低、时间短，从而抑制了晶粒长大，获得致密度高、晶粒细小、结构均匀的多晶材料，使得由于残余气孔率对光线的散射得以大幅度降低，提高了多晶陶瓷透光性。其强韧化机制主要是细晶强化、相变增韧、微裂纹增韧等强韧化机理。同时重点研究了Er3+对ZrO2 (YSZ)透明陶瓷相结构和光学性能（透光率、吸收光谱、荧光光谱、激发光谱等）的影响，以及980 nm LD 激发下Er3+:ZrO2(YSZ)透明陶瓷的上转换发光性能，其机理是随Er3+离子浓度增加导致其交叉弛豫，共振增强，上转换发光强度增加，当Er3+离子浓度的继续增加，产生级联能量传递，发生能量的非辐射跃迁，从而又降低了发光效率。同时研究了煅烧温度对Ho3 +/Yb3 +共掺杂8YSZ 纳米粉体荧光光谱和上转换发光性能的影响，探讨了晶粒结晶完整影响发光强度的机理，获得了较高效率的上转换发光。.本项目采用微波烧结低温制备一种高强韧、高透光率纳米ZrO2 (YSZ)透明陶瓷并实现较高效率上转换发光，并与甘肃稀土新材料股份有限公司联合研发。本项目有助于进一步深入理解透明陶瓷的设计、制备、发光和强韧化机理研究中的科学问题，为其在飞机的前舱、装甲车的观察窗、导弹的整流罩、高温窗口、红外窗口和红外探测等方面应用奠定良好基础。