Investigation of Characterization of Zerodur Glass Ceramics Used in Aerospace to Predict the Relationship between Surface Roughness and Subsurface Damage

Abstract

Due to the brittle nature of the optical parts used in the grinding process to obtain a good surface quality, surface roughness and subsurface damage occur after the machining. These subsurface damages must be detected and destroyed with the help of post-process processes such as polishing. Because detecting these damages is time-consuming and costly, many researchers have tried relationship between subsurface damage and surface roughness since it is easier to detect and measure. In this study, Zerodur glass ceramic material characterization tests were carried out to predict the surface roughness and damage under the surface, and the material properties were determined to be specific to the sample. The grinding parameters taken from the previous studies and the values given for surface roughness and subsurface damage were examined with the help of the Lambropoulos theoretical model. The results theoretically showed that with the characterization of material properties different from those given in the literature, even if the parameters used in the experimental study do not change, much more severe subsurface damage will be created on the sample, and the load value applied to the material will increase significantly. For this reason, it is crucial to determine the material's mechanical properties by performing characterization tests before all material grinding and post-processing processes.

Keywords

• Zerodur
• Surface Roughness
• Subsurface Damage
• Indentation Process
• Microhardness

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