Influence of the Ni/Co Mass Ratio on the Microstructure and Properties of Quaternary Cu-Ni-Co-Si Alloys

Abstract

The properties and microstructural evolution of quaternary Cu-Ni-Co-Si alloys with different Ni/Co mass ratios are investigated systematically. These alloys exhibit higher mechanical properties when the Ni/Co mass ratio is 1.12-1.95 (NC-4-NC-5) and show excellent electrical conductivity when the Ni/Co mass ratio is 0.05-0.5 (NC-1-NC-3). With an increase in the Ni/Co ratio, the dimension of precipitated phase continues to increase and the grain size also visibly grows and coarsens. At the same time, the precipitation process of the NC-5 alloy is the most adequate, resulting in the highest mechanical properties. In addition, the precipitated phase in the alloys was confirmed to be the (Ni, Co)2Si composite phase. The number of Ni2Si phases in the precipitated phase gradually increased, and the Ni atoms exhibited the strongest co-segregation alongside the increasing Ni/Co ratio. Compared with the alloy without a Co element, the addition of Co helped refine the grain size and accelerate the precipitation of the particle phase and purify solute atoms in the matrix, thereby simultaneously improving mechanical properties and conductivity. The present work provides a new method for the development of multicomponent Cu-Ni-Si-Co-X alloys with outstanding comprehensive performance.

Effects of Co Addition on the Microstructure and Properties of Elastic Cu-Ni-Si-Based Alloys for Electrical Connectors

“…According to the calibration results, the two sets of spots are the same precipitated phase δ-(Ni, Co) 2 Si in the NC-1, NC-2 and NC-3 alloys, with an orthorhombic structure of two variant forms δ 1 and δ 2 . Similarly, the spots in the NC-4 alloy are all the same precipitated phase δ-Ni 2 Si with two variants of δ 1 and δ 2 , which is consistent with the previous results [ 4 , 20 ]. The orientation relationships (ORs) of the precipitates and matrix can be calibrated as (220) Cu //( ) δ1 //( ) δ2 and [ ] Cu //[ ] δ1 //[ ] δ2 .…”

“…Combined with previous research, the change of the Ni/Si mass ratio had a strong effect on the microstructure and properties of ternary Cu-Ni-Si alloys [ 18 , 19 ]. A similar method was used to study Cu-Ni-Co-Si alloys and found that different Ni/Co mass ratios also had a great impact on the microstructure and properties of the alloys [ 20 ]. Therefore, it is necessary to further explore the relationship between the internal microstructure and performance of quaternary Cu-Ni-Co-Si alloys to provide more guidance for the subsequent design and development of new alloys.…”

Hot Deformation Behavior and Microstructure Evolution of Cu–Ni–Co–Si Alloys

“…These precipitates can be confirmed as Ni 2 Si, Co 2 Si or (Ni,Co) 2 Si according to the select area diffraction pattern, as shown in Figure 7b. Based on the literature [26][27][28], the precipitates can be identified as (Ni,Co) 2 Si in the Cu-1.7Ni-1.4Co-0.65Si alloy. When the hot deformation temperature increases to 910 °C, the density of dislocation clearly decreases and dynamic recrystallization occurs, as shown in Figure 8, which can reduce the work hardening [29,30].…”

First-principles study of the mechanical and thermodynamic properties of aluminium-doped magnesium alloys

“…Many factors can affect the mechanical and thermodynamic properties of metal alloys, such as mass ratio, phase composition and grain boundaries. [24][25][26][27] Among these factors, the mass ratio of elements in alloys is fundamental and has a signicant impact on their performance. 24,25 For Mg-Al alloys, some studies on mass ratios have also been reported.…”

“…[24][25][26][27] Among these factors, the mass ratio of elements in alloys is fundamental and has a signicant impact on their performance. 24,25 For Mg-Al alloys, some studies on mass ratios have also been reported. [28][29][30] Using the atomic substitution method, Zhou et al 28 obtained the supercell of Mg 15 Al and studied the mechanical and electronic properties.…”