International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

Polymers are used in every walk of life now-a-days. They are not even hundred years old but playing significant role in every sector of life such as sports, defense, medical, automobile, electrical, agricultural etc. In the beginning, polymers were considered as excellent insulators but conductive polymers are available now. Polymers have good water resistance but some polymers are good absorber of water. The present article deals with monitoring the changes in the mechanical properties of composites with polymer matrix. The composite was formed from the PA matrix and glass fibers. The mechanical properties, impact strength (Charpy) and micro-hardness (Vickers) were evaluated on samples of the composite before and after UV radiation on the sample.

AISI 316Ti stainless steel is prone to local corrosion in aggressive chloride environments. Its resistance to pitting in the absence and presence of molybdate inhibitor was tested by two independent tests with different mechanisms of corrosion process: by exposure (24 hours immersion test) and electrochemically (potentiodynamic polarisation test). Both tests were carried out in 1 M chloride acidic solution without inhibitor and with two different amounts of added inhibitor (concentration ratio inhibitive/aggressive anions was 1:10 and 1:20 respectively), at room temperature. Results of immersion tests were evaluated on the bases of corrosion rates calculated from corrosion losses during immersion and by morphology of pitting. Results of potentiodynamic polarisation tests were evaluated by pitting potentials.

The present article deals with monitoring the changes in the mechanical properties of composites with polymer matrix. The composite was formed from the PA matrix and glass fibers. The composite contains 10 – 30 % glass fibers. The mechanical properties, tensile strength and flexural strength were evaluated on samples of the composite before and after UV radiation on the sample. The largest decline endpoints was recorded in 500 hours of UV exposure. Light microscopy was evaluated distribution of glass fibers in the polymer matrix and the presence of cracks caused by UV radiation.

Austenitic stainless steels are widely used for various industrial, construction and biomedical application because of their high resistance to uniform corrosion and suitable mechanical properties. However, they are prone to local corrosion in aggressive halides environments. In contrast of corrosion resistance research in chloride containing environments, there have been few investigations into the effect of fluorides on passivity breakdown and pitting corrosion of stainless steels. This article focuses on the effect of fluoride added to chloride solution on corrosion resistance of AISI 316L stainless steel. Evaluation is based on results of exposition immersion tests performed in 0.9 % NaCl, 0.9 % NaCl + 0.05 % NaF and 0.9 % NaCl + 0. 5 % NaF solutions (42 days) and on results of cyclic potentiodynamic polarization tests performed in the same solutions.