Influence of 1%Nb Solute Addition on the Thermal Stability of In Situ Consolidated Nanocrystalline Cu

Abstract

Nanocrystalline (nc) Cu and Cu-1% Nb bulk materials are synthesized using a combination of cryogenic and room temperature ball milling. The grain size values of these in situ consolidated Cu and Cu-1% Nb, determined using transmission electron microscopy, are found to be 22 nm and 18 nm, respectively. In this investigation, isochronal heat treatments are performed for 1 h to establish grain size and microstructural changes as a function of temperature. The annealing of nc Cu-1% Nb at a temperature of 1073 K reveals a slight increase in the average grain size from 18 to 45 nm. The grain size of nc Cu, however, increases from 22 nm to about 3 μm after annealing at the same conditions. The present results indicate that solute entrapment plays a major role in thermal stability of the high purity contaminant-free Cu with the addition of only 1 at% Nb after annealing for 1 h up to a homologous temperature of 0.8. Kinetic stabilization via clustering of Nb atoms on the grain boundaries and the triple junctions is also observed after annealing at high temperature for longer times.

The Effect of the Milling Vial Shape on the In-Situ Consolidation of a Nanocrystalline Al-Li-GNPs Nanocomposite Synthesized by Room Temperature Ball-Milling

“…In this regard, several studies investigating the ball-milling of face-centered cubic (FCC) metals have reported a so-called in-situ consolidation phenomenon where the milled powder is also consolidated during the milling process (SamadiKhoshkhoo et al, 2015;Hegedűs et al, 2017;Abaza et al, 2019;Ahmed et al, 2020;Ahmad et al, 2020b). Thus, instead of refined powders or agglomerated particles, the formation of relatively large spherical bulk particles of the milled material is reported using a combination of cryomilling and room temperature milling processes.…”

Investigation on the Thermodynamic Stability of Nanocrystalline W-Based Alloys: A Combined Theoretical and Experimental Approach

“…In fact, several NC metallic alloys have shown higher thermal stability with respect to their single-component counterparts. Along these lines, binary [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ], ternary [ 24 , 25 , 26 , 27 , 28 , 29 ], and higher order systems have been investigated [ 30 , 31 , 32 , 33 , 34 ].…”