Thermal and Mechanical Properties of AlN Composite Fabricated with AlN Short Fiber

Abstract

Aluminum nitride (AlN) composites were fabricated with AlN short fiber in order to improve the fracture toughness. The average diameter of the AlN short fiber was approximately 7.0 μm, whereas the average long-axis length was estimated to be about 200 μm. AlN powder compact with 3 mass % of Y₂O₃ and 0 ∼60 mass % of AlN short fiber addition was hot-pressed at 1760 °C for 0.5 h under the pressure of 8 MPa. Relative densities of the AlN composites with AlN short fiber addition exceeded 98%, independent of the amount of fibers. The fracture toughness of the composite with 30 mass % short fiber (3.2 MPa•m^1/2) was higher that of monolithic AlN ceramics (2.0 MPa•m^1/2).