Low-kV Quantification of Refractory Borides for High Temperature Applications

EDS spectrum of HfB2 acquired at 5 kV; Inset picture shows magnified spectra in the 100 - 250 eV region

Ultra-high temperature (UHT) boride ceramics are a class of refractory materials that are made for extreme environments. Borides of transition metals like Hafnium (Hf), Titanium (Ti), Niobium (Nb) and Zirconium (Zr) have the highest known melting points of any material. This makes them very suitable for aerospace and defense applications.
Chemical analysis of HfB2 using EDS is challenging since the X-ray fluorescence emitted by B (Z=5) is absorbed by Hf (Z=72). Additionally, the primary K-line of B (183 eV) overlaps with the N-line of Hf (202 eV) (Fig. 1).
To quantify HfB2 correctly, the acquisition parameters and quantification models must be carefully chosen. In the present work, HfB2 has been analyzed and quantified at 5 kV.

Fig. 1: EDS spectrum of HfB2 acquired at 5 kV; Inset picture shows magnified spectra in the 100 - 250 eV region