Anti-perovskite carbides and nitrides A3BX: A new family of damage tolerant ceramics.

Synergy effect of high stiffness and good damage tolerance is always the focus of the development of novel structural materials. Herein, a new strategy on the future damage tolerant material design is proposed to merge the strong covalent bonds into the easy shear deformed A 3 B metallic box. This goal is realized by studying 126 A 3 BX phases and establishing a database on their mechanical properties through high-throughput first principles calculations. The combination strategies of A 3 B metallic box and XA 3 octahedra show intensive influences on the expected mechanical properties. The family includes 49 quasi-ductile compounds. Among them, four compounds (Ti 3 AlN, Mn 3 CuN, Ti 3 TlN and Ni 3 SnN) exhibit excellent damage tolerance and the other six compounds (Mn 3 NiN, Mn 3 GaC, Mn 3 GaN, Mn 3 SnC, Cr 3 SnN, Co 3 AlC) show both damage tolerance and high stiffness. Their competitive high temperature properties are demonstrated through the detailed investigation on the typical cases of Co 3 AlC and Ti 3 TlN. This study leads a novel direction for the design of the future quasi-ductile and high stiffness ceramics. [ABSTRACT FROM AUTHOR]