The Research On The Process And Influence Factors Of Real-time Crack Monitoring Based On Quantum Dots

Crack is the most dangerous defect in the structure and may lead to equipment failure and even cause serious safety accidents.However,limited by high cost and complex structure,it is still difficult to realize real-time monitoring in large scale during the industry process.Therefore,it appears to be extremely important to develop new technology in order to realize the real-time monitoring.Considering that quantum dot(QD)is a stress-dependent material,the paper is mainly based on the CdSe/ZnS QDs.With the mixing of epoxy,the QDs-Epoxy resin is made to form a film on the sample so as to detect the crack in real time,and then,the related factors are investigated.The main research content and conclusions in this paper are as follows:(1)It is found that,by the observation of fluorescence microscope,there is a bright line in the crack of film while a PL enhancement region near the metal crack during the monitoring of macro crack.(2)With the experiment of investigating relationship between PL intensity signal and crack length,the optimal film thickness is given for detecting different crack size.Meanwhile,by analyzing the difference between these two different PL enhancement phenomenon,different mechanisms for macro crack and micro crack are proposed.(3)As to macro crack,the synchronism between the length of film crack and metal crack is analyzed.For micro crack,via simulation and investigating on related factors,it is proved that the PL enhancement phenomenon is closely related to the stress distribution in matrix and it also has a strong relationship between the interaction of QDs and matrix.