Browsing by Author "Wędrychowicz, Mateusz"

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Access status: Open Access ,
Effect of rapid solidification aluminum alloys with different Si contents on mechanical properties and microstructure
(2016) Wzorek, Łukasz; Wiewióra, Marcel; Wędrychowicz, Mateusz; Skrzekut, Tomasz; Noga, Piotr; Wiewióra, Jakub; Sajdak, Wojciech; Richert, Maria Wiesława
Rapid solidification is a relatively new and effective way of producing ultrafine-grained UFG aluminum alloys with enhanced mechanical properties. Due to a significant cooling rate close to nearly 106 K/s, it is possible to obtain a material with grain size far below 100 nm. In the present study, RS aluminum alloys with an Si content in a range of 5–10 wt% were produced during melt spinning. As a result, materials in the form of ribbons were produced. The as-received flakes were subjected to cold pressing into cylindrical billets with a diameter of 40 mm. Hot extrusion of pre-compacted material was subsequently performed at a temperature of 450°C with a press ram speed of 3 mm/s and extrusion ratio of ? = 25. In this work, the influence of brittle phases on the mechanical properties of as-extruded rods will be examined. Both tensile and microhardness tests were performed in order to determine the mechanical properties of the obtained profiles. It has been shown that brittle-phase refinement during melt spinning significantly influences the mechanical properties of the tested materials.
Access status: Open Access ,
Possibility of Al-Cu composite manufacturing from fine metal fractions by recycling process
(Wydawnictwa AGH, 2017) Wzorek, Łukasz; Wędrychowicz, Mateusz; Wiewióra, Marcel; Noga, Piotr; Skrzekut, Tomasz; Wzorek, Agata; Łyp-Wrońska, Katarzyna
Plastic consolidation of highly fragmented materials is a cost-effective way to recover aluminum alloys. In this process, metal in the form of chips, powders, or ribbons omits the melting step that is typical for conventional scrap recycling, by that, it significantly reduces both energy expenses and material losses. By reducing the number of operations, the cost of labor and expenditures on environmental protection can be decreased. In addition, the solid bonding of metals in highly dispersed forms allows us to create heterogeneous structures that could be difficult to obtain in traditional processes. In the present study, the influence of the addition of Cu powder (99.7 wt.%) on the bonding quality of aluminum powder (99.7 wt.%) during hot extrusion is being examined. The examined materials contained aluminum powder with the addition of 5 wt.% of Cu powder. The mixture of these powders were cold compacted to produce an 80-mm-long charge for the extrusion process. Plastic consolidation was conducted at three different temperatures: 300°, 350°, and 400°C. As a result, rods 8 mm in diameter were obtained. Mechanical tests combined with microstructure observations and electrical conductivity tests were performed for the as-extruded materials.
Access status: Open Access ,
Selection of optimal conditions for solid bonding of the AlSi11 aluminium alloy
(2016) Wzorek, Łukasz; Wędrychowicz, Mateusz; Skrzekut, Tomasz; Noga, Piotr; Wiewióra, Marcel; Wiewióra, Jakub; Sajdak, Wojciech; Richert, Maria Wiesława
In the present work, the optimal conditions for solid bonding of fragmented aluminum alloy were determined. The research was conducted on metal chips from the AlSi11 TM aluminum alloy after the turning process. The selection of proper bonding conditions was based on the results of tensile tests and surface quality analysis of as-extruded profiles. The extrusion process was conducted within a temperature range of 350–500°C, with a ram speed of 13 mm/s. Extrusion ratio ? was 25. As a reference material, a sample from the solid AlSi11 IM alloy has been extruded under the same conditions.The influence of temperature during direct extrusion on both maximum force and surface quality of obtained profiles has been determined. With reference to tensile test results, no significant influence of temperature on the mechanical properties has been noticed. Profiles extruded at 500°C were characterized by visible cracks on the surface, oriented perpendicular in the direction of extrusion. Moreover, surface flaws were also noticed in profiles extruded at 350°C.A tensile test revealed a strong relationship between the extrusion conditions and plasticity of solid bonded rods. A shiny and smooth surface was obtained only in profiles extruded at a temperature range of 400–450°C.