The effect of Nb-addition on the L12 precipitates of rapidly-solidified Al-Cr-Zr alloy

Enhancing elevated temperature strength of copper containing aluminium alloys by forming L12 Al3Zr precipitates and nucleating θ″ precipitates on them

“…These ordered spherical precipitates were found throughout the microstructure without any discontinuous precipitation. Chuan and Tu 19 have shown that the addition of Nb to Al-Zr based alloy minimizes the lattice misfit and interfacial energy that reduces the tendency to discontinuous precipitation of L1 2 Al 3 Zr. From the atom probe measurements, the spherical precipitates are found to be Zr-rich with small enrichment in Nb and Cu with respect to the α-Al matrix (Figure S2b ).…”

“…We have utilized a significant difference in temperatures required for nucleation/formation of these precipitates from the solute supersaturated α-Al to design the microstructure through a new three step heat treatment. A small amount of Nb was added to avoid discontinuous precipitation 19 .…”

Experimental Phase Diagram of the Al-Er-Zr Ternary System

“…This phase can pin the mobile dislocations and migrating grain boundaries, thus improve the mechanical properties of Al alloys. [5,6] It is well known that small addition of rare earth elements is of great importance to improve the mechanical properties of Al-based alloys by the mechanisms of eliminating impurities, purifying melt, refining as-cast structure, retarding recrystallization and refining precipitated phases. [7][8][9] Over the past decade, Scandium (Sc) has been most commonly studied as micro-alloying element in the case of Al-based alloys.…”