Structure, Phase Composition and Properties of Al3Er Master Alloys Obtained by “Hydride Technology” and Mechanical Treatment

The incorporation of rare-earth metals beneficially influences the microstructure, mechanical properties, and overall performance of base alloys by forming modifying and strengthening intermetallic phases. This investigation focuses on the production of Al3Er master alloy using “hydride technology,” involving the preliminary hydrogenation of erbium and mechanical processing of starting components. The study demonstrates the impact of pre-mechanical treatment of an Al–Er powder mixture on the structure and properties of Al3Er master alloy. The master alloy obtained with pre-mechanical processing exhibits a homogeneous structure comprising an aluminium matrix with evenly dispersed Al3Er inclusions. Thin interlayers of dispersed eutectics, enriched with approximately 20–25 wt % erbium, are observed along the boundaries of the Al solid solution. Structural analysis of Al3Er master alloy using the Rietveld method revealed two metallic phases: aluminium solid solutions (~95.14%) and the intermetallic compound Al3Er (~4.86%). With machining, the average Vickers microhardness value of regions predominantly composed of Al3Er was (92.4 ± 8.0) HV, reaching a maximum of (105 ± 8.0) HV. In contrast, the average microhardness value of the master alloy obtained without machining in these areas was (68.4 ± 8.0) HV.