Browsing by Subject "tellurium"

Now showing 1 - 3 of 3

Access status: Open Access ,
Electrochemical behavior of tellurium in acidic nitrate solutions
(2014) Rudnik, Ewa; Biskup, Przemysław
Electrochemistry of tellurium stationary electrode was studied in acidic nitrate solutions with pH 1.5 – 3.0. Cyclic voltammetry indicated that two products were formed at potentials above 300 mV (SCE): soluble $HTeO_{2}^{+}$ (500 mV) and sparingly soluble $H_{2}TeO_{3}$ (650 mV), but the former seemed to be an intermediate product for $TeO_{2}$ precipitation on the electrode surface. Formation of the solid products as porous layers was almost undisturbed and no electrode passivation was observed. $H_{2}TeO_{3}$ and $TeO_{2}$ dissolved to $HTeO_{2}^{+}$ under acidic electrolyte, but this process was hindered by pH increase. Cathodic polarization of tellurium electrode below -800 mV was accompanied by evolution of $H_{2}Te$, which was then oxidized at the potentials approx. -700 mV. $H_{2}Te$ generated in the electrochemical reaction decomposed to elemental tellurium as black powdery precipitates in the bulk of the solution and a bright film drifting on the electrolyte surface.
Access status: Open Access ,
Influence of the Addition of Tellurium and Heat Treatment on the Microstructure of Hypoeutectic White Cast Iron
(AGH University Press, 2025) Trela-Przybyło, Alicja; Kawalec, Magdalena; Górny, Marcin
This study investigates how the addition of tellurium and heat treatment affects the microstructure of hypoeutectic white cast iron that has been modified with alloying elements such as titanium, chromium and vanadium. Samples with different chemical compositions were prepared and subjected to a two-step heat treatment process. Microstructural characterisation was performed using optical and scanning electron microscopy. The results show that introducing tellurium significantly affects the morphology of the cementite and carbide phases, causing them to fragment and become more evenly distributed. Furthermore, heat treatment enhanced matrix refinement and promoted phase stability. The combination of tellurium addition and heat treatment produced the most favourable microstructures, characterised by the high dispersion of hard phases within a fine-grained matrix.
Access status: Open Access ,
Metallurgical processing of Al-Si alloys with increased iron content using sodium, strontium, and tellurium
(AGH University of Science and Technology Press, 2018) Pokusová, Marcela; Berta, Igor; Murgašová, Marta
This paper presents the results of research focused on the processing of the hypoeutectic Al-Si alloy with an increased iron content of 1.75 wt.%. The physical-metallurgical method was used to eliminate the undesirable effect of the iron rich b-phase on the mechanical properties of the casting material using liquid metal modification by strontium, sodium, and tellurium. The chemical composition of an experimental material didn't contain any elements for the solid-solution strengthening of a matrix, therefore, the presented results can document the capabilities of modifying the ?-phase under a minimum influence on the properties of the basic Al-Si system.