In this study, the mechano-chemical properties of aromatic polymer polyetheretherketone (PEEK) samples, irradiated by high energy electrons at 200 and 400 kGy doses, were investigated by Nanoindentation, Brillouin light scattering spectroscopy and Fourier-transform infrared spectroscopy (FTIR). Irradiating electrons penetrated down to a 5 mm depth inside the polymer, as shown numerically by the monte CArlo SImulation of electroN trajectory in sOlids (CASINO) method. The irradiation of PEEK samples at 200 kGy caused the enhancement of surface roughness by almost threefold. However, an increase in the irradiation dose to 400 kGy led to a decrease in the surface roughness of the sample. Most likely, this was due to the processes of erosion and melting of the sample surface induced by high dosage irradiation. It was found that electron irradiation led to a decrease of the elastic constant C11, as well as a slight decrease in the sample’s hardness, while the Young’s elastic modulus decrease was more noticeable. An intrinsic bulk property of PEEK is less radiation resistance than at its surface. The proportionality constant of Young’s modulus to indentation hardness for the pristine and irradiated samples were 0.039 and 0.038, respectively. In addition, a quasi-linear relationship between hardness and Young’s modulus was observed. The degradation of the polymer’s mechanical properties was attributed to electron irradiation-induced processes involving scission of macromolecular chains.
24 October 2024 in Advances in Science and Technology Research Journal
This study investigates the effects of electron beam irradiation on the mechanical and tribological properties of polyetheretherketone (PEEK), with particular focus on modifications resulting from the application of Litol-24 lubricant. Samples of pre-treated PEEK were irradiated at doses of 100,...
27 September 2024 in Bulletin of Shakarim University. Technical Sciences
The study demonstrates the significant effects of electron beam irradiation on the tribological and mechanical properties of polytetrafluoroethylene (PTFE). Electron beam irradiation, a method using highvelocity electrons to modify material properties, was applied to PTFE to potentially enhance its wear resistance and mechanical hardness, which are critical for applications under increased wear conditions. In the experiments, PTFE samples were irradiated at varying doses, and their wear resistance, microhardness, and surface roughness were evaluated post-irradiation. Tribological test results showed a notable improvement in wear resistance and microhardness with increasing radiation doses. Specifically, irradiated samples exhibited reduced wear volume and enhanced surface characteristics compared to the unirradiated sample. The irradiated sample (PTFE-2) showed the highest resistance to abrasive wear and a significant increase in surface hardness, indicating that electron beam irradiation effectively strengthens the material by inducing cross-linking and other structural modifications within the polymer matrix. Additionally, the study highlighted changes in surface roughness: irradiated samples exhibited altered roughness parameters that contributed to improved wear resistance. These changes can be explained by the physical and chemical transformations induced by electron beam exposure, which modify the surface and subsurface regions of the polymer. This study confirms that electron beam irradiation is an effective method for enhancing the mechanical and tribological properties of PTFE, making it more suitable for advanced engineering applications where high durability and resistance to extreme conditions are required. The findings open new avenues for the use of PTFE in sectors requiring high performance, extending its application beyond traditional fields.