Reaction Sintering of Biocompatible Al(2)O(3)–hBN Ceramics

[Image: see text] Biocompatible Al(2)O(3)–hBN ceramic was sintered from AlN and B(2)O(3) precursors by reaction hot pressing at 1750 °C and 30 MPa for 8 min. The ceramic was compared to nonreactive (NR) one sintered from Al(2)O(3) and BN under the same sintering conditions. The NR ceramic possesses 9% porosity as opposed to only 2% porosity for the reaction sintered Al(2)O(3)–hBN. The reaction sintered ceramic has crack resistance in the region of 5.0 ± 0.1 MPa·m(1/2), which is approximately 20% higher than previously reported pure Al(2)O(3) or Al(2)O(3)–hBN sintered without reaction support. The higher amount of hBN in the developed Al(2)O(3)–hBN material (27 vol %) facilitates hardness lowering to the region of 6 GPa, which is closer to the bone hardness and makes the ceramic machinable. Reaction sintering of the Al(2)O(3)–hBN composite opens a new area of creation and formation of load-bearing Al(2)O(3)–hBN ceramic bioimplants.