Temperature dependence of the fracture strength of composite corundum materials reinforced with Ni and NiAl particles

The mechanical properties (fracture strength and Vickers microhardness HV) of corundum-based composite materials containing disperse Ni and NiAl particles are studied. The material samples are prepared by sintering in vacuum at 1500°C or through hot compaction at a temperature ranging from 1470 to 1570°C. The fracture strength of the samples based on Al 2 O 3 -Ni (2.2 vol %) and prepared through hot compaction at 1570°C varies from 3.4 to 5.4 MPa m 1/2 at 20°C as the NiAl content varies from 5 to 40 vol %, respectively. When the Ni content is increased to 6.5 vol %, the fracture strength values vary from 3.1 MPa m 1/2 (5 vol % of NiAl) to 5.1 MPa m 1/2 (40 vol % of NiAl). The maximum fracture strength for the Al 2 O 3 -Ni (6.5 vol %)-NiAl (40 vol %) samples is 7.36 MPa m 1/2 at 500°C.