*3.3. TEM Photographs and EDS Analysis Results of Coarse Particles in Solution-Treated Alloy*

Figure 3 presents TEM photographs and EDS analysis results of coarse particles in the solution-treated Cu-Cr-Zr-Ni-Si alloy. It can be seen from Figure 3a that needle-like particles with a length of 100–200 nm (marked by red circle) grow from the grain boundary. The EDS analysis results indicate that the particles are a compound containing Cu and Zr elements. Figure 3c presents a nearly spherical phase with a size of about 200 nm in diameter, and it is proved to be a kind of (Si, Cr, Cu)-rich compound. In addition, a lath phase with a size of 300 nm × 100 nm, which mainly contains Si, Cr, Ni, Zr and Cu elements, can be observed inside the grains in Figure 3e. Similar results had been obtained from other samples which contain coarse particles with the same morphology. It can be inferred that the TEM and EDS analysis results on morphology and the contained elements of Figure 3 are consistent with those of the SEM and EDS analysis in Figure 2.

**Figure 3.** TEM images and EDS analysis results of coarse particles in solution-treated Cu-Cr-Zr-Ni-Si alloy. (**a**,**b**) needle-like particle and EDS analysis results; (**c**,**d**) nearly spherical particle and EDS analysis results; (**e**,**f**) lath-like particle and EDS analysis results.
