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The influence of the thermo-oxidative aging semi-crystalline polyethylene terephthalate process on the thermal and mechanical properties was analysed in the article. For this purpose, PET was aged at 140 °C for 21, 35 and 56 days. The research showed that as a result of aging, the amount of the crystalline phase increases by about 8%, which translates into the properties of the aged material. The glass transition and melt temperature of lamellar crystals formed during first and second crystallisation increase with aging. The mechanical properties of the material were analysed in the temperature range of 25 to 75 °C. The tests were showing an increase in Young’s modulus and a decrease in elongation at the break as a result of aging. This phenomenon was particularly visible during tests at 75 °C and during the morphological observation of the fracture surface, where the fracture character of the material changes from ductile to brittle. In the case of the material aged for the longest time, the temperature has a negligible influence on the elongation at break.

The anodization of commercially pure Ti alloy (99.5 wt %) and two biomedical titanium alloys, Ti6Al7Nb and Ti6Al4V, was performed, and the resulting anodic oxides were studied. The biomedical alloys were made by Laser Engineered Net Shaping. The glycol-based and glycerol-based electrolytes with 0.3 M ammonium fluoride and 2 wt % of deionized water content were tested. It was found that electrolyte type as well as the chemical composition of the base substrate affected the final morphology and chemical composition of the anodic oxide formed. A higher current density, ionic mobility, and oxide growth rate were obtained in glycol-based electrolyte as compared to those obtained in glycerol-based electrolyte for all tested alloys. A self-organized nanotubular and nanoporous morphology of the anodic oxide in both types of electrolyte was obtained. In each electrolyte, the alloy susceptibility to oxidation increased in the following order: Ti6Al4V < Ti 99.5% < Ti6Al7Nb, which can be correlated to the oxidation susceptibility of the base titanium alloy. It was observed that the more impurities/alloying elements in the substrate, the lower the pore diameters of anodic oxide. There was a higher observed incorporation of electrolyte species into the anodic oxide matrix in the glycerol-based electrolyte compared with that in glycol-based electrolyte.

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Results of the first principle study on a fabrication of FeAl intermetallic based alloy with an addition of nanometric αAl 2 O 3 (n-Al 2 O 3 ) particles by the LENS method and a subsequent characterization of the as received materials' structure and properties, are shown in the present work. A series of samples were manufactured using LENS technique while a control of temperature and the size of melted metal pool.The presence of ceramics nanoparticles was not directly confirmed by microscopy observations. Neither aluminum nor oxygen content was not elevated in the material with n-Al 2 O 3 content. Although, indirect methods revealed influence of n-Al 2 O 3 addition on the manufactured elements structure. Analyses of porosity has shown that addition of 2% vol. n-Al 2 O 3 significantly decreases this feature (~1%), as compared to the reference material made of pure FeAl intermetallic alloy (~5%). The addition of n-Al 2 O 3 causes an increase of grain size in Fe40Al intermetallic alloy. An oxidation resistance has been also improved what was associated to the n-Al 2 O 3 addition. Four times lower increase of samples mass was noticed for sample with the n-Al 2 O 3 addition as compared to the pure Fe40Al intermetallic alloy.