Formation of equiaxed crystal structures in directionally solidified Al-Si alloys using Nb-based heterogeneous nuclei

The design of chemical compositions containing potent nuclei for the enhancement of heterogeneous nucleation in aluminium, especially cast alloys such as Al-Si alloys, is a matter of importance in order to achieve homogeneous properties in castings with complex geometries. We identified that Al3Nb/NbB2 compounds are effective heterogeneous nuclei and are successfully produced in the form of Al-2Nb-xB (x = 0.5, 1 and 2) master alloys. Our study shows that the inoculation of Al-10Si braze alloy with these compounds effectively promotes the heterogeneous nucleation of primary α-Al crystals and reduces the undercooling needed for solidification to take place. Moreover, we present evidences that these Nb-based compounds prevent the growth of columnar crystals and permit to obtain, for the first time, fine and equiaxed crystals in directionally solidified Al-10Si braze alloy. As a consequence of the potent heterogeneous particles, the size of the α-Al crystals was found to be less dependent on the processing conditions, especially the thermal gradient. Finally, we also demonstrate that the enhanced nucleation leads to the refinement of secondary phases such as eutectic silicon and primary silicon particles

Development Of Al-B-C Master Alloy Under External Fields

This study investigates the application of external fields in the development of an Al-B-C alloy, with the aim of synthesizing in situ Al3BC particles. A combination of ultrasonic cavitation and distributive mixing was applied for uniform dispersion of insoluble graphite particles in the Al melt, improving their wettability and its subsequent incorporation into the Al matrix. Lower operating temperatures facilitated the reduction in the amount of large clusters of reaction phases, with Al3BC being identified as the main phase in XRD analysis. The distribution of Al3BC particles was quantitatively evaluated. Grain refinement experiments reveal that Al-B-C alloy can act as a master alloy for Al-4Cu and AZ91D alloys, with average grain size reduction around 50% each at 1wt%Al-1.5B-2C additions

Refinement of Mg alloys crystal structure via Nb-based heterogeneous substrates for improved performances Dataset

Microstructures, Grain size measurements & Tensile propertie

Microstructural Evolution in Infiltration-Growth Processed MgB2 Bulk Superconductors Dataset

<p>Data for reacted MgB₂ samples in an Infiltration and Growth process at varying heating conditions includes XRD patterns, phase quantification, Self-field J_c, hardness, SEM images, composition and schematics. </p> <p> </p> <p> </p> <p><b>Softwares</b></p> <p>Origin, Microsoft PowerPoint</p> <p> </p> <p> </p> <p><b>Subjects</b></p> <p>MgB₂, Superconductivity, Infiltration and Growth</p> <p> </p> <p><b>Sponsorship</b></p> <p>EPSRC (Grant: EP/K031422/1)</p

Recycling of Aluminium cast alloys with high Fe impurities: Al-12Si-2Fe

Recycling Aluminium cast alloys with high Fe impurities<br

Recycling of Aluminium cast alloys with high Fe impurities: Al-6Si-2Fe

Managing high Fe impurity upto 2wt%, in Al-Si cast alloys.<br