TeO2晶体的力学性能及缺陷分析

摘要：用坩埚下降法成功生长了声光用二氧化碲晶体，生长的晶体大小（37mm×43mm×47mm），重点研究了二氧化碲晶体不同晶面的力学性能，以及不同结晶面的腐蚀形貌。材料力学性能的好坏严重影响着其服役效果和服役寿命。本论文选择具有重要应用背景的声光晶体二氧化碲（TeO2）晶体的（001）面和（110）面为研究对象，采用显微压痕实验，研究了TeO2晶体的力学性能。利用显微硬度仪测得的TeO2晶体的压痕直径，计算TeO2晶体的断裂韧度，测量出TeO2晶体（001）面和（110）面在0.100kg、0.200kg、0.300kg载荷下的文氏硬度分别为（3.32、3.22、3.10；4.78、4.44、4.00）。（110）面的断裂韧度随着载荷的加大，逐渐降低。脆性指数越来越大，相应的屈服强度越来越小。（001）面和（110）面的硬度值不同，是由于各个晶面原子堆积密度不同决定的。经过XRD测试获得二氧化碲单晶的峰图，表明了其结晶度良好，通过腐蚀实验，观察TeO2晶体（001）面和（110）面的腐蚀坑形貌。总结出晶体中的腐蚀坑会影响TeO2晶体的硬度及裂纹开裂方向。7301
关键词：二氧化碲、显微硬度、断裂韧性、缺陷
Mechanical properties and defect analysis of paratellurite crystal
Abstract：Mechanical properties are important aspects of material performance, which mainly manifests for the external interaction against the materials in the process of producing, processing and using. So, this paper chooses (001) and (110) surface of an acousto-optic crystal called TeO2, which has important application background, as its object of the research. What’s more, micro-indentation experiment system is used in the thesis to study the mechanical properties of TeO2.After using a micro hardness tester, impression diameter of TeO2 was correctly measured, and then fracture toughness of TeO2 was calculated. The data showed that the Vickers hardness of (001) and (110) surfaces were respectively (3.32, 3.22, 3.10; 4.78, 4.44, 4.00) under the load of 0.1 kg, 0.2kg, 0.3kg. In addition, the Vickers hardness of (110) surface was gradually reducing, while the load was increasing. Therefore, the hardness values of (001) and (110) surfaces are different, which shows uneven packing density in the crystals of TeO2. Through the corrosion experiment, the defects on (001) and (110) surfaces of TeO2 crystal can be further observed. Finally, this paper obtained the peak figures of single crystal of TeO2 after XRD test.
Keywords: Tellurium dioxide; Micro-penetration hardness; Fracture toughness; Defects
目录
第1章绪论   1
1.1 引言   1
1.2 声光晶体   2
1.2.1 声光晶体及其应用   2
1.2.2 TeO2声光晶体   4
1.3 TeO2晶体研究现状   4
1.3.1 TeO2的晶体生长   4
1.3.2 TeO2晶体性能   5
1.4 晶体的力学性能   5
1.4.1 力学性能参数   8
1.4.2 声光晶体力学性能   8
1.5 课题的研究目的与意义   8
第2章实验   9
2.1 晶体生长实验   9
2.2 样品制备（二氧化碲晶体的加工和处理）   10
2.3 XRD样品表征   12
2.4 晶体硬度测试   13
2.5 晶体断裂韧性测试   15
第3章实验结果与讨论   17
3.1 显微压痕测试结果   17
3.1.1 二氧化碲晶体的实验数据记录   17
3.1.2 硬度实验数据处理与分析   18
3.2 断裂韧度测试结果   19 TeO2晶体的力学性能及缺陷分析:http://www.751com.cn/cailiao/lunwen_5200.html