A novel method to characterize the residual stress on the fused silica surface based on the evolution of the atomic point defects

The residual stress would have a significant impact on the service performance and fatigue life of the fused silica (non-crystal material) components (e.g., Hemispherical Shell Resonator). However, there is still no effective method for characterizing the residual stress on their working surfaces. Therefore, it is essential to develop a novel method for characterizing the residual stress on fused silica surfaces. Herein, the residual stress is found to significantly affect the mechanical properties of fused silica surfaces. On the basis of the study on the photoluminescence (PL) properties of residual stress zones, atomic point defects are found to be closely related to the residual stress. Based on an investigation of the PL properties of different types of mechanically processed surfaces, four types of point defects (ODCII, STE, Si clusters and NBOHCI) have been determined. On the basis of the molecular dynamics (MD) simulation results and the PL experiments on different types of mechanically processed surfaces, STE point defects at the atomic scale are found to be closely related to the residual stress for the first time. Based on this, PL-detection method is proposed to characterize the residual stress on the material surface for the first time. Besides, the relative amount of STE point defect (K=S/S0) is first proposed to quantitatively characterize the residual stress. In sum, this work determines the structure at the atomic scale which is closely related to the residual stress and opens a convenient door to quantitatively characterize the residual stress with PL-detection method. It could also provide a reference for the characterization and even the alleviation of the residual stress on the surfaces of other non-crystal materials.