Metallurgy and Foundry Engineering
Loading...
ISSN 1230-2325
e-ISSN: 2300-8377
Issue Date
2017
Volume
Vol. 43
Number
No. 1
Description
Journal Volume
Metallurgy and Foundry Engineering
Vol. 43 (2017)
Projects
Pages
Articles
Preliminary studies on hydrometallurgical tin recovery from waste of tin stripping of copper wires
(2017) Rudnik, Ewa; Wincek, Dawid
This paper presents the results of tin leaching and electrowinning from SnO₂ waste originating from the industrial process of tin stripping of copper wires. The sludge was leached by acids (sulfuric, hydrochloric, tartaric, oxalic) and sodium hydroxide at various temperatures (40–80°C). The highest efficiency of tin leaching (12–18%) was obtained in an oxalic solution, while the lowest effectiveness (0.2–0.5%) was found for sulfuric acid. Tin leaching was accompanied by a transfer of copper residues to the solution. The electrowinning stage was realized under potentiostatic and galvanostatic conditions using oxalate solutions. Cyclic voltammetry was applied to select the potentials for the selective deposition of metals.
Structure and properties of hot-rolled and annealed AZ61 magnesium alloy
(2017) Sułkowski, Bartosz
Magnesium alloy AZ61 was processed by hot rolling up to a large thickness reduction (~89%) in several routes with intermediate annealing. The hot rolling process was conducted at 450°C and at a 1.5 s−1 strain rate. The structure and texture evolution as well as the mechanical properties during processing were investigated. The structure studies showed that, during the hot-rolling process, a large number of twins formed, which had an impact on the mechanical properties of the hot-rolled samples. After annealing for 15 minutes, the twins were no longer observed in the annealed samples, causing a significant decrease in hardness. Moreover, an investigation of the hardness showed that annealing for 15 minutes did not remove all of the hardening effects nor did the hardness of the annealed samples decrease to the value before hot rolling. The texture investigations showed that the texture of the hot-rolled samples was a typical basal-type texture. However, the basal pick was split into two tilted towards the rolling direction (RD). The texture changed during annealing while the new strong texture components evolved. The annealing led to an increased intensity of <1010>{1120} texture component and enhanced ductility. It was concluded that the texture changes observed in the present investigations may lead to the enhanced ductility of magnesium alloys and, therefore, help us design a deformation scheme for magnesium alloys consisting of several thermomechanical routes.
Channel cross-section influence on effective strain distribution in ECAP process
(2017) Chyła, Paweł; Bednarek, Sylwia; Łukaszek-Sołek, Aneta
This study compares the numerically determined strain distributions after the application of the method of equal-channel angular pressing. The calculations were performed for four variants of the channel cross-sectional shapes – square, circular, and two rectangular ones with the same transverse surface area. The calculation results have been demonstrated as maps of effective strain distribution in the stabilized process.
The influence of SiC particle size on mechanical properties of aluminium matrix composites
(2017) Wąsik, Anna; Leszczyńska-Madej, Beata Katarzyna; Madej, Marcin
The main aim of this study was to determine the influence of SiC particle size on the mechanical properties of aluminum matrix composites. The reinforcing phase was introduced into the aluminum matrix in two different particle sizes: a coarse fraction with particle size ranging from 40 to 60 µm, and a fine fraction with particle size of less than 2 µm. The SiC particles were added in various quantities equal to 2.5, 5, 7.5, and 10 wt% in order to determine the influence of different contents of the reinforcing phase on the density, hardness, and compressive strength of the obtained composite materials. By using scanning electron microscopy (SEM), the microstructure observations were performed and allowed for defining the influence of matrix/reinforcement particle size ratio (PSR) on the distribution of reinforcement particles in the matrix. The Al-SiC composites were prepared through the conventional powder metallurgy technique, including compaction under a pressure of 300 MPa and a sintering process in a nitrogen atmosphere at 600°C. Applying the reinforcing phase with the particle size (40–60 µm) similar to matrix (<63 µm) allowed us to obtain a more-uniform distribution of SiC particles in the matrix than after introducing the fine fraction of reinforcement (2 µm). The mechanical properties of the Al-SiC composites increased with increases in the weight fraction of the reinforcing phase, wherein this effect is more visible for composites reinforced with SiC particles of finer gradation.
Selection of protective coatings obtained by plasma-spraying method for foundry industry
(2017) Richert, Maria Wiesława; Nejman, Ilona; Zawadzka, Paulina; Kacprzyńska-Gołacka, Joanna
This article presents results from the studies of protective coatings applied to industrial graphite molds used for the casting of non-ferrous metals. The selection of coatings was based on the results of measurements of surface wettability by liquid copper and microstructure examinations. The study involved industrial graphite molds with single-layer protective coatings of Al₂O₃ + 30%C and ZrO₂-Y₂O₃ + 30%C as well as two-layer protective coatings of Al₂O₃ + 30%C /glassy carbon and ZrO₂-Y₂O₃ + 30%C /glassy carbon.