Detailed Investigation of Core-Shell Precipitates in a Cu-Containing High Entropy Alloy

作者：Alam T; Gwalani B; Viswanathan G^*; Fraser H; Banerjee R^*

来源：JOM, 2018, 70(9): 1771-1775.

DOI：10.1007/s11837-018-2935-8

Due to the competing influences of configurational entropy and entropy of mixing, in recent years, secondary (including intermetallic) phases have been reported in many high entropy alloy (HEA) systems. These secondary phases offer great potential in terms of strengthening the HEA beyond the solid solution strengthening effects, and as such are of great interest in regards to alloy design for engineering applications. The present research investigates novel nano-scale core-shell precipitates forming within the disordered bcc matrix phase of an Al2CrCuFeNi2 HEA, utilizing complementary high-resolution microscopy techniques of atom probe tomography (APT) and transmission electron microscopy (TEM). The size, morphology, and local chemistry of these core-shell precipitates was measured by APT, and the composition was further corroborated by high-resolution scanning transmission electron microscopy-energy dispersive spectroscopy in an aberration-corrected TEM. Furthermore, high-resolution TEM imaging of the core-shell structure indicates that the Cu-rich core exhibits a bcc crystal structure.

• 出版日期2018-9