PSI - Issue 72

E.A. Gachegova et al. / Procedia Structural Integrity 72 (2025) 260–264

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Fig. 2. Residual stress profiles: (a) along the X-axis; (b) stresses along the Y-axis

Fig. 2. Changes in surface microhardness of the samples for different absorbing coating materials.

The roughness measurements yielded different results (Fig. 3). The treatment with all three layers increased the surface roughness. The greatest change in this parameter was observed when using black paint. The indicator reached a value of 0.771 compared to 0.085 for the base material, while the smallest increase was noticeable in PVC tape. The obtained values correlated well with the residual stress on the surface. When comparing them with roughness, we can see that the larger the residual stresses, the rougher the surface is.

Fig. 3. Surface roughness of samples after laser shock peening with different coatings.

4. Conclusions All used coatings have withstood processing at an energy density of 10 GW/cm 2 , maintaining their integrity and can be used in industry. Residual stress profiles show that the most effective are aluminum foil and black paint, as these absorbing coating materials show the highest maximum values of compressive residual stress and the greatest depth of penetration. The analysis of the microhardness of the samples did not reveal any significant changes in depth. The use of laser shock peening led to an increase in microhardness for all types of absorbent coatings. As for roughness, the lowest value was achieved after processing with hardening using PVC tape. From a technological point of view, the advantage of using foil is its ability to be applied quickly compared to black paint, which must be applied in layers. However, there is a risk of losing adhesion between the foil and the part when there are small radii of curvature or more complex geometries. This can lead to the rupture of the protective layer or formation of defects on the surface of the material at the contact boundary. In these cases, using paint may be