PSI - Issue 37

7

I. Shardakov et al. / Procedia Structural Integrity 37 (2022) 1065–1072 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

1071

Figure 7. Uniaxial deformation corresponding to the appearance of cracks on the sample surface at different fluences (average of 3 samples and standard deviation ) 4. Discussion The results of the experiments on uniaxial deformation of polyethylene film samples indicate that statistically significant differences are observed between the values of the effective elastic modulus of the samples treated with plasma with different fluence. If the fluence exceeds 5  10 15 ions / cm 2 , the elastic modulus of the carbonized layer stops changing. The character of the obtained dependence of the modulus of the surface layer on the fluence is in agreement with the results of spectrophotometry. For specimens treated with a fluence of 10 15 ion / cm 2 , the formation of cracks begins at a significantly higher level of deformation than for specimens with higher fluence treatment. Apparently, at a low intensity of treatment, the surface layer significantly inherits the properties of the polyethylene substrate. At a high fluence, the carbonization of the surface layer increases significantly, and it becomes more brittle. This is indicated by the small values of the breaking deformation. 5. Conclusions A method is proposed for determining the elastic modulus of a carbonized layer formed by ion-plasma treatment on polymer films. This technique made it possible to establish the dependence of the elastic modulus of the carbonized layer on the fluence of ion-plasma treatment. From the obtained dependences it follows that at fluences above 5  10 15 ion / cm 2 the value of the elastic modulus of the carbonized layer becomes constant, and this is confirmed by the results of spectrophotometry. The dependence of the uniaxial deformation of the sample, which correlates with the occurrence of surface cracks, on the ion-plasma treatment fluence is obtained. It was found that the carbonized layer formed by treatment with a fluence of 10 15 ion / cm 2 can withstand deformations up to 25% without cracking. The carbonated layer can have different mechanical and optical properties depending on the type of polymer. In the future, we plan to investigate the properties of the carbonized layer on the surface of polyurethanes.