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Abstract: In the field of surface treatment, laser colour marking can be used to produce coloured marks on the surfaces of metals. Laser colour markings can be applied to various materials, but on titanium alloys a wide spectra of vivid colours can be achieved. This study presents an analysis of the corrosion properties of laser treated surfaces that were exposed to aggressive environments. Different samples were prepared with laser light of various power intensities and processing speeds. The samples were prepared on low alloyed Ti. Electrochemical, spectroscopic and microstructural analyses were conducted in order to study the properties of the laser treated surfaces. Corrosion testing showed different effects of laser power and production speed on the properties of the laser treated surfaces. It was shown that a high intensity and slow processing rate affect the surfaces by forming oxides that are relatively stable in a corrosive environment of 0.1 M NaCl. Spectroscopic investigations including scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) analyses showed the differences in chemical structure of the surface layer formed after laser treatment. Similarly, microstructural investigations showed different effects on the surface and sub-surface layer of the laser treated samples.
Keywords: Ti alloy, laser treatment, XPS, corrosion
Published in DiRROS: 25.10.2023; Views: 367; Downloads: 144
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Abstract: As-produced and heat-treated TiAlV samples were prepared by selective laser melting and compared to wrought samples of identical chemical composition. Microstructural, corrosion, and spectroscopic studies of additively manufactured samples in artificial saliva at 37 °C, with NaF and at pH 2.3 were as a novelty combined with metal ion release during 42 days immersion. In artificial saliva higher amount of ions was released on SLM specimen when compared to wrought alloy. The total amount of ions released from SLM specimen in AS containing NaF was 10-times higher than in AS, while in AS with lactic acid it was 100-times higher.
Keywords: Ti6Al4V, SLM, corrosion, ion release, XPS, ToF-SIMS
Published in DiRROS: 31.05.2023; Views: 299; Downloads: 249
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Abstract: This article deals with modifications of wood surface properties induced by different drying temperatures. The aim of the study was chemical and physical characterization of a wood surface concerning low and high temperature exposure. Additionally, the correlation between the chemical composition of a wood surface and its wetting capacity were investigated. X-ray photoelectron spectroscopy and contact angle measurements were conducted. Two wood species, yellow poplar (Liriodendron tulipifera) and southern pine (Pinus taeda) were studied. The results showed that the percentage of carbon increased with drying temperature, and consequently, the percentage of oxygen decreased. The samples exposed to high drying temperatures indicated a higher content of extractives on the wood surface. These samples exhibited the highest contact angle and the lowest wettability
Keywords: površina lesa, sušenje, kontaktni kot, rentgenska fotoelektronska spektroskopija, omočitev, ekstraktivne snovi, wood surface, drying, contact angle, XPS, wettability, extractives
Published in DiRROS: 12.07.2017; Views: 4565; Downloads: 1917
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