**3. Results**

#### *3.1. Feedstock Powder Characterisation*

The typical angular morphology of the fused and crushed powder particles is shown in the SEM micrograph in Figure 1. The granulometric parameters d10, d50, and d90, which are also given in Table 1, confirm only minor differences of their particle sizes, which makes them suitable for blending.

**Figure 1.** SEM images of the feedstock powders. (**a**) Al2O3. (**b**) Cr2O3. (**c**) TiO*<sup>x</sup>*.

According to the XRD measurements, as shown in Figure 2, the alumina and chromia feedstock powders consist only of α-Al2O3 (corundum) and Cr2O3 (eskolaite), respectively. In the SEM investigation of the chromia powder, small amounts of metallic chromium were detected, which do not appear in the XRD pattern. A large number of peaks in addition to those of rutile were detected for the TiO*x* powder. These additional peaks, which are not labelled in the pattern in Figure 2, belong to substoichiometric titanium oxide phases. The presence of the (110) peak of rutile at 2θ = 27.4◦ indicates that local concentrations of oxygen are closed to stoichiometry, while, in other regions, disordered oxygen-deficient structures exist. According to the gravimetric measurements in another study, *x* in TiO*x* powder is about 1.9 [19].

**Figure 2.** XRD pattern of the feedstock powders.
