Experimental investigations and thermodynamic modeling in the ZrB2Ni section of the BNiZr system

• Melting equilibria occurring in the Ni-rich part of the BNiZr system were studied.
• A combined experimental (DTA, XRD) and computational (CALPHAD) approach was used.
• A solubility range in the Zr2(Ni21−xZrx)B6 phase was found to exist for 0.14 ⩽ x ⩽ 0.68.
• The obtained results can help in interpreting data coming from wetting tests.

An investigation of melting equilibria in the Ni-rich part of the BNiZr system was carried out by means of a combined experimental and computational approach, in order to improve the interpretation of wetting experiments of BNi alloys on ZrB2 substrates. Several samples along the NiZrB2 vertical section, close to the Zr2(Ni21−xZrx)B6 ternary phase, were prepared by arc-melting the pure metals; the samples were thoroughly studied by means of powder X-ray diffraction and SEM–EDS, and then analyzed by DTA in order to obtain their transition temperatures. The results were used to improve the CALPHAD thermodynamic modeling of the BNiZr system. A solubility range of the ternary phase between x = 0.14 and x = 0.68 was detected, due to the mixing of Zr and Ni in the 4a crystallographic site.