fig4

Figure 4. Transmission electron microscopy (TEM) observation of the produced high-entropy alloy (HEA) with the sample extracted from Area 3 (as indicated in Figure 1), showing the co-existence of matrix phases of the (A) disordered face-centred cubic (FCC) and (B) ordered L12 structures as well as the (C) needle-shaped Ni3Ti type precipitation and (D) spherical Ti-rich precipitation. The insets in (A) and (B) are corresponding selected area electron diffraction (SAED) patterns. The energy dispersive X-ray spectroscopy (EDS) results from the precipitates are included in (C) and (D). High-resolution TEM (HRTEM) data and the fast Fourier transform (FFT) pattern from the spherical precipitation are also shown in (D).