Hot-pressing of BeO ceramics and its thermal conductivity and flexural strength.

Due to its excellent strength and high thermal conductivity, beryllium oxide (BeO) is widely used as a fuel matrix material and neutron moderator in nuclear reactors. In the preparation of bulk BeO materials, previous research on the hot-pressing sintering methods is insufficient. This paper mainly introduces the process of hot-pressing sintering, and uses orthogonal experiments with different process parameters to explore their influences on the grain size and porosity of the products, and how to affect their flexural strength and thermal conductivity as well. Molecular dynamics simulations have also been used to study the growth of the amorphous phase in BeO ceramics. In addition, a relatively optimized preparation scheme, that is, holding at 1500 °C for 30 min and pressure of 20 MPa can be obtained. Under the optimized parameter, the flexural strength of the product can reach 244.74 MPa, and its thermal conductivity can reach 179 W/(m*K) at 200 °C, and 31 W/(m*K) at about 1000 °C. It provides a reference for the preparation of high performance BeO ceramics. [ABSTRACT FROM AUTHOR]