No abstract

Nb-B refiners are thought to be more stable than Ti-based refiners, becoming promising inoculants for Al alloys. However, the combined effect of adding NbB on dendritic scale and grain size (GS) with a wide range of solidification cooling rates remains unknown. It is well known that the shape of the α-Al phase is determined by a balance between inoculating components content/type and cooling rate. The inoculation of Al alloys with Ti-based inoculants, for example, significantly lowers GS while having no significant effect on secondary dendritic arm spacing (SDAS). Increased cooling rate, on the other hand, results in grain refinement, but only to a limited extent. Because of a combination of appropriate mechanical properties and suitable electrical conductivity, the 6201 alloy is widely employed in the transmission and distribution of electricity. Despite being a thermomechanically treated alloy, it goes through a melting and solidification process first, which entail research on this level of processing. ln order to assess the impact of adding NbB to the 6201 alloy’s refinement level (either macro or microscopic), directional solidification (DS) and centrifugal casting (CC) processes were utilized to obtain samples for examination. For the DS samples, cooling rates were determined, whereas for the CC samples, they were approximated for two alloys: 6201 (reference) and 6201-0.5wt.%Nb-0.1wt.%B alloys. Comparing the refined and non-refined alloy results, the GS of the DS 6201-NbB alloy was much smaller (about 13 times) across a range of cooling rates from 0.5 K/s to 20 K/s, whereas only 3 times smaller GS values were detected for CC samples at higher cooling rates. For particular cooling rates of 2.5 K/s and 240 K/s, the GS/SDAS ratios of values related to slow and fast cooling were 6.9 and 6.2, demonstrating that the cooling rate sensitivity of both GS and SDAS was similar in the NbB-inoculated alloy.

The market for electric vehicles is growing, seen as the best alternative to replace internal combustion-powered vehicles. Recent developments in electric vehicles have allowed them to reach a level of performance, comfort, and safety that enables them to compete with traditional vehicles. However, several studies are directed towards increasing the autonomy of these vehicles, aiming at weight reduction of structural components. Aluminum alloys are increasingly being chosen to produce structural elements, due to their low density and suitable properties. The 6000 Al alloys are often used in chassis and bodywork. In view of this, this work proposes a comparison of 6000 series alloys, by means of thermodynamic (using Thermo-Calc®) and property computations (Ansys® Granta EduPack and Selector) to select the best alloys considering application properties, processability, and environmental impact. It was observed that the T6 heat-treated alloys presented better mechanical properties, but, on the other hand, they have more impact on the environment. As such, the 6010-T6 alloy was classified as the best alloy regarding performance, the 6061-T4 alloy the best in terms of processability, and the 6009-T4 alloy presented the lowest environmental impact. The 6111-T4 alloy was highlighted as the alloy showing the best balance between the examined properties.