Cyclic deformation and fatigue cracking behaviors of Cu–28wt%Ag binary alloy

Abstract

The cyclic deformation and fatigue cracking behaviors of coarse-grained Cu-28wt%Ag binary alloy were investigated under axial plastic strain amplitudes ranging from 10 À4 to 7.5 Â 10 À4 . It was found that the cyclic stress of the Cu-Ag alloy increased rapidly in the initial tens of cycles and became saturation with further cyclic deformation. The cyclic saturation stress increased with increasing the plastic strain amplitude. The interfaces are classified into two categories based on the orientations of the eutectic and the dendrites, i.e. type I and type II interfaces. The surface damage morphologies show that fatigue cracks normally nucleated either along the type I interfaces or along the slip bands (SBs), while no cracking occurred along the type II interface. Fatigue striations with different spacings appeared on the fracture surface, and secondary cracks along the striations were also observed. Based on the experimental results, the cyclic deformation and fatigue cracking behavior of the Cu-Ag binary alloy were discussed in detail.

Effects of Route on Microstructural Evolution and Mechanical Properties of Cu-8 Wt Pct Ag Alloy Processed by Equal Channel Angular Pressing

“…[41] In addition, the dendrite and the eutectic component also may have the orientation relationship. [37,42] Under the as-received condition, the eutectic region is in the micron/submicron range, whereas the precipitates are 50 nm to 90 nm in diameter. [37] Figure 2(a) shows that the elongated eutectic runs parallel to the axial direction of the rod, and some particle-like and rod-like Ag-rich precipitates exist near the grain boundaries.…”

“…[49] This can be from the good deformation compatibility between the eutectic and the matrix. [37,42] The information on HABs and grain sizes is shown in Figure 12. The fraction of HABs is obtained from the orientation distribution, as shown in Figure 13, whereas the grain size is acquired from the mapping information in Figure 11.…”