Lubricant oil contained Al2O3 and six squares BN nanometer grain was used to do the friction and wear experiments for friction pairs sample which is made of the same materials of locomotive engine parts that are easy to wear.

Y elastic constants of polycrystalline materials with hexagonal system structure

In hexagonal system, there is 180° secondary rotation twin with(003)as twinning plane and direction as twinning axis.

Brillouin scattering for hexagonal system has arbitrary rotation symmetry about the 6 fold axis of the system.

Biomimetic synthesis of highly oriented 3D-hexagonal mesoporous silica thin films by evaporation-induced self-assembly process;