(Ca,Sr,Ba)ZrO3: A promising entropy-stabilized ceramic for titanium alloys smelting

A novel entropy-stabilized (ES) (Ca,Sr,Ba)ZrO 3 ceramic has been designed and synthesized by pressureless sintering of CaZrO 3 , SrZrO 3 and BaZrO 3 powders mixtures at 1450 °C, 1500 °C and 1550 °C for 3 h. X-ray diffraction, scanning electron microscopy and transmission electron microscopy analyses collectively indicate that a single solid solution is formed with a homogeneous distribution of metal elements after sintering at 1550 °C. The relative density and hardness of the ES (Ca,Sr,Ba)ZrO 3 ceramic sintered at 1550 °C are 97.79 % and 10.84 ± 0.33 GPa, respectively. This ES (Ca,Sr,Ba)ZrO 3 exhibits lower thermal conductivity from 373 K to 1073 K than their constituting zirconates , CaZrO 3 , SrZrO 3 and BaZrO 3 . Most importantly, the ES (Ca,Sr,Ba)ZrO 3 ceramic possesses good corrosion resistance to TiNi alloy melt and no distinct reaction layer exists between TiNi alloy and ES (Ca,Sr,Ba)ZrO 3 ceramic in the contact region. The combination of these properties indicates that ES (Ca,Sr,Ba)ZrO 3 ceramic is promising for use as a novel crucible material for the melting of titanium alloys .