Influence Mechanism of Ageing Parameters of Cu-Cr-Zr Alloy on Its Structure and Properties

Abstract

The Cu-1.0% Cr-0.1% Zr alloy in a solid solution state was investigated by ageing treatments at different temperatures and holding times. The structure and performance were characterized and tested by using X-ray diffraction (XRD), a transmission electron microscope (TEM), a universal material testing machine, and an eddy conductivity detector. The influence laws of ageing temperature and the holding time on the structures and properties of the Cu-Cr-Zr alloy were analyzed. Results demonstrated that, with the increase in ageing temperature and holding time, the percentage and size of the Cr precipitated phase increased, and the dislocation density decreased. The tensile strength first increased to the peak value and then decreased. The electrical conductivity increased and the amplitude decreased. The tensile strength of the alloy reached the peak (359 ± 2 MPa) after ageing at 450 °C for 60 min, and the electrical conductivity was 91.9 ± 0.7% IACS. In addition, in the ageing precipitation process, the chromium precipitated phase had face-centered cubic structure (FCC) and body-centered cubic structure (BCC) structures, and the FCC Cr phase can be transformed into a BCC Cr phase. FCC Cr, BCC Cr, and Cu3Zr precipitation phases maintained different orientation relationships with the Cu substrate.

Laser–Direct Current arc Hybrid Additive Manufacturing of Cu-Cr-Zr Alloy: Microstructure Evaluation and Mechanical Properties

“…As shown in Figure 9b, the Cr precipitates show circular and oval shapes, which is consistent with the discovery by Chbihi et al [34]. Ma et al [35] concluded that there were concentration gradients among different sizes of Cr precipitates in the Cu matrix. The diffusion of Cr atoms promotes the formation of large-sized Cr phases and the dissolution of small-sized Cr phases.…”

Investigation of structural, electrical and tribological properties of duplex surface treated and aged Cu−Cr−Zr alloy

“…The mechanical properties of the CuÀ CrÀ Zr alloy are improved by the aging process. This is because high density chromium nano-precipitated phases are produced after aging [11,12]. The addition of chromium and zirconium to copper alloys improves the wear resistance, strength and heat resistance of the alloys.…”

“…The interaction between chromium and zirconium element atoms is good. Therefore, refining the chromium precipitated phases can further increase the copper alloy's strength [11]. Chromium plays an important role in the mechanical and tribological properties of not only copper alloys but also different alloys [13][14][15].…”