Analytical investigation of various mechanical properties and environmental strength for ceramics sprayd materials

本文研究了陶瓷喷涂材料的环境强度。研究结果如下：1.从电化学角度分析，陶瓷喷涂材料的缝隙腐蚀敏感性变高，耐蚀性变差.通过对Al_2O_3喷涂材料残余应力的热弹塑性有限元分析，发现随着涂层厚度的增加，Al_2O_3涂层边缘的残余拉应力增大.从陶瓷喷涂材料的疲劳性能和腐蚀疲劳性能来看，裂纹的存在对陶瓷喷涂材料的疲劳强度有很大的影响，而NiCrAlY喷涂材料的疲劳腐蚀性能得到改善.从陶瓷喷涂材料的应力腐蚀性能考虑，Al_2O_3喷涂材料的强度提高是由于下层残余拉应力的松弛.从陶瓷喷涂材料的高温腐蚀性能来看，在Na_2SO_4、NaCl和V_2O_5环境中，ZrO_2 - 8%Y_2O_3喷涂材料的腐蚀比ZrO_2-25%CeO_2喷涂材料严重。通过超声检测发现，喷涂界面存在剥离状缺陷和杂质缺陷。

In this report environmental strength of ceramics sprayd materials are investigated. The results are as follows.1. From the electrochemical consideration, it is revealed that susceptibility of the crevice corrosion becomes higher and corrosion resistance becomes lower in the ceramics sprayd materials.2. From the thermal-elastic-plastic analysis of residual stress by FEM for the Al_2O_3 sprayd materials it is revealed that as the film thickness increases the tensile residual stress increases at the edge of the Al_2O_3 film.3. From the consideration of fatigue and corrosion fatiguc properties for the ceramics sprayd materials, it is revealed that the fatigue strength of the ceramics sprayd materials is much influenced by the existence of cracks and the fatigue corrosion properties are improved in NiCrAlY sprayd materials.4. From the consideration of stress corrosion cracking properties for the ceramics sprayd materials, it is revealed that the strength is improved in Al_2O_3 sprayd materials because of the relaxation of tensile residual stress of lower layr.5. From the consideration of high temperature corrosion properties for the ceramics sprayd materials, it is revealed that corrosion occurs more severely for the ZrO_2 8%Y_2O_3 sprayd materials than for the ZrO_2-25%CeO_2 sprayd materials in the environments of Na_2SO_4 NaCl and V_2O_5.6. By supersonic inspection it is revealed that the peeling like defects and impurity defects exist in the sprayd interface.