Rapid Optimization of Microstructure and Mechanical Properties of a Selective Laser Melted AlMgScZr Alloy Under Electropulsing Treatment

Owing to the insufficient strength of selective laser melted (SLM) AlMgScZr alloy, an effective post‐treatment is required. Electropulsing treatment (EPT) offers distinct advantages over conventional thermal methods, such as rapid processing and energy efficiency. Accordingly, EPT was applied to the SLM AlMgScZr alloy, and its effects on microstructure evolution, mechanical properties, and strengthening mechanisms were systematically investigated. The heterogeneous microstructure, which consisted of coarse columnar grains (CGs) and fine equiaxed grains (EGs), remained unchanged, whereas the precipitates underwent remarkable evolution as the Sc/Zr‐rich and Fe/Mn‐rich precipitates were produced and uniformly distributed after EPT at a set current of 100 A. Compared with the as‐built specimen, the yield strength and tensile strength increased after EPT. Thermodynamic and kinetic analyses were carried out to explicate the intrinsic mechanisms of precipitation behaviors under EPT. Furthermore, the contributions of solid‐solution strengthening, grain‐boundary strengthening, dislocation strengthening, and precipitation strengthening were discussed for both the as‐built and V‐EPT100 specimens. In general, EPT demonstrates promising potential as an effective method for enhancing the strength of additively manufactured aluminum alloys.