裂纹尺度突变信息实时反馈的喷涂层疲劳磨损失效预警研究

项目名称： 裂纹尺度突变信息实时反馈的喷涂层疲劳磨损失效预警研究

项目编号： No.51305397

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 机械、仪表工业

项目作者： 朴钟宇

作者单位： 浙江工业大学

项目金额： 25万元

中文摘要： 面向热喷涂层疲劳磨损过程中的损伤隐蔽性、失效突发性及寿命演变规律复杂等技术难题，开展基于裂纹信息实时反馈的预警等科学问题研究，对于提高喷涂层服役安全性具有重要的科学意义和工程应用价值。本项目提出了基于裂纹尺度突变信息实时反馈的喷涂层疲劳磨损失效预警方法，采用声发射信号反馈喷涂层进行性损伤状态，揭示喷涂层寿命演变规律。主要研究内容包括：（1）探索最佳表征喷涂层疲劳开裂的声发射信号特征参量，辅以TEM/SEM/FIB-SEM等损伤表征技术，揭示声发射信号特征与喷涂层疲劳断裂的映射关系；（2）运用经典力学理论，阐明交变载荷作用下的喷涂层裂纹运动规律，揭示喷涂层裂纹萌生、扩展的动态演变过程，建立裂纹动态扩展预测模型；（3）提出基于实时信号提示的喷涂层疲劳磨损失效预警方法，建立合理高效的预警模型，阐明基于裂纹动态扩展理论的预警机理。本项目体现了多学科的交叉融合，其成果将丰富热喷涂基础理论体系。

中文关键词： 喷涂层；接触疲劳；失效；预警；表面完整性

英文摘要： The process of fatigue wear of the sprayed coating shows hidden and sudden. The regularity of the lifetime is also complex. So the prewarning investigation based on on-line response of crack is necessary. Which is important for promoting the service security of sprayed coating. In the present project, the prewarning method is proposed based on on-line information feedback of the crack scale mutant. the acoustic emission (AE) technique is introduced to on-line monitor the damage status. The regularity of the lifetime is investigated.The main contents are listed as follow: (1) AE signal parameters which are fit for characterizing the fracture of sprayed coating are selected. The high-accuracy observations of surface/subsurface microstructures of sprayed coatings are conducted. Then the contact between AE signal and fatigue fracture of sprayed coating is built. (2) The regularity of fatigue crack of sprayed coating under alternate load is investigated based on AE signal and classical mechanics. The dynamic process of initiation and propagation of crack revealed. (3) The prewarning investigation based on on-line signal warning is conducted by using the feature of AE signal response and model of crack dynamic propagation.The effective and reasonable prewarning model is established. And the relevant mechanism is expla

英文关键词： Sprayed coating；Contact fatigue；Failure；Prewarning；Surface integrity