Microstructure and mechanical properties of h-BN/Y2SiO5 composites

h-BN/Y2SiO5 composites were prepared by in situ hot pressing method. The mechanical properties can be improved by increasing the amount of Y2SiO5 phase in the range of 30–50 vol%. The flexural strength and compressive strength of h-BN/50 vol%Y2SiO5 reach 144±6 and 404±20 MPa, respectively. Especially, the composites show higher flexural strength than either h-BN or Y2SiO5. The residual compressive stress, high elastic modulus, and grain refinement are believed to be beneficial for material strength. Meanwhile, good machinability is maintained due to the low hardness of the second phase.