NiAl–Al 2O 3 composites produced by pulse plasma sintering with the participation of the SHS reaction

Abstract

The paper presents the results of examinations of the NiAl–Al 2O 3 sinters (13, 38 and 55 vol% of Al 2O 3) produced from a mixture of nickel, aluminum and alumina powders in a single technological process, using the pulse plasma sintering (PPS) method. By subjecting the elemental powders to a PPS process for 900 s, we obtained NiAl–Al 2O 3 composites of a hardness ranging from 480 HV10 (13% Al 2O 3) to 680 HV10 (55% Al 2O 3). The fracture toughness of the sintered materials depended on the amount of the dispersed Al 2O 3 phase. When examined with a Vickers indenter under a load of 10 kg, the composite containing 13% of Al 2O 3 showed no cracking. In the composites with 38% Al 2O 3 and 55% Al 2O 3 contents, the value of K IC was 9.1 and 8.2 MPam 1/2, respectively.