PSI - Issue 81

Valeriy Lazaryuk et al. / Procedia Structural Integrity 81 (2026) 529–535

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a) V=105 m/s

b) V=150 m/s

c) V=195 m/s

d) V=240 m/s

e) V=285 m/s

f) V=300 m/s

Fig. 9. Micrographs (a – g) presenting transverse-crack morphologies at various scanning speeds. A fixed field of view of 1.10 х 0.82 mm was used throughout, providing a uniform geometrical basis for crack-density quantification.

Fig. 10. Crack density on scribed grooves versus the linear energy of CO 2 -laser scribing.

When the crack-density response of silicate glass is plotted against linear energy, E lin , a clear, stable interval of about 100 – 300 J/m appears. Within this range, the crack density remains low, and the groove morphology remains reproducible. Above this limit, crack density increases, indicating the onset of uncontrolled thermal cracking. This relationship allows the operating window of the process to be identified directly. For example, keeping E lin within 150 – 250 J/m at a scanning speed of 300 mm/s corresponds to a power of roughly 45 – 75 W, which matches the experimentally observed stable regime. In this way, the linear energy input approach provides a physically grounded basis for selecting CO 2 -laser scribing parameters that minimise defect formation in silicate glass. 4. Conclusions The study of CO ₂ -laser scribing of silicate glass has identified a specific energy window within which groove formation remains thermally stable. This stability minimizes defects, allowing for the reproducible creation of micro-relief patterns. A quantitative analysis of linear energy input revealed that the transition from stable to unstable scribing regimes is influenced by local heat accumulation and the onset of uncontrolled fractures within the scribed groove. The established relationship among scanning speed, absorbed energy per unit length, groove geometry, and the nature of thermal damage provides a reliable framework for predicting and controlling defects that arise from the scribing process. These findings