Strength of Zirconium Diboride to 2300°C

The strength of zirconium diboride ( ZrB 2 ) ceramics was measured up to 2300°C, which are the first reported measurements above 1500°C since 1970. ZrB 2 ceramics were prepared from commercially available powder by hot pressing. A mechanical testing apparatus capable of testing material in the ultra‐high temperature regime with atmosphere control was built, evaluated, and used. Four‐point bend strength was measured as a function of temperature up to 1600°C in air and between 1500°C and 2300°C in argon. Strength between room temperature and 1200°C was ~390 MPa, decreasing to a minimum of ~170 MPa between 1400°C and 1500°C, with strength increasing to ~220 MPa between 1600°C and 2300°C.