Laser additive manufacturing of compositionally graded AlCrFeMoVx (x=0 to 1) high-entropy alloy system

Abstract

The current study discusses a novel combinatorial high-throughput approach for assessing the compositionmicrostructure-hardness relationship, using laser deposited compositionally graded AlCrFeMoVx (0 < x < 1) high entropy alloy (HEA) as a candidate system. The composition gradient was achieved from AICrFeMo (with 0.3 at. % V) to AICrFeMoV (with 18.5 at. % V) over a length of similar to 20 mm, deposited using the laser engineered net shaping process from a blend of elemental powders. Scanning electron microscopy, X-ray diffraction, and transmission electron microscopy were used to characterize the alloys. A single solid solution (SS) body-centered cubic (bcc) structure is observed throughout the compositional range. The high solubility of V in this novel alloy system offers a broad range of solid solution strengthening of a compositionally complex but structurally simple bcc matrix. The hardness of the alloy increases from 485 Hv to 581 Hv on increasing V from 0.3 to 18.5 at. %. The solid solution hardening model for dilute solutions underestimates the strengthening of the alloy. The current study presents a novel and efficient method for microstructural screening of the bulk alloys for optimization of the microstructure and properties.