OXIDATION RESISTANCE OF SINTERED CHROMIUM NITRIDE COMPOSITE

A hard material of chromium nitride can be used under 973 K in an atmosphere. Raw powder materials of CrN and Fe were mixed by ball milling. The raw powder materials were sintered by a hot press process at various temperatures for 3.6 ks with compressive stress of (15, 30, 45) MPa under an atmosphere of 0.1 MPa N 2 . After estimating the properties of the sintered material, specimens were used for oxidation test. There is no Cr 2 O 3 but (Cr, Fe) 2 O 3 on the specimen surface after oxidizing the (Cr, Fe)N ceramic at 1073 K for around 960 ks under an atmosphere. However, there is not almost able to measure its increase of mass during oxidation. Vickers hardness of all specimens increased during oxidation. These facts indicate that the sintered bulk (Cr, Fe)N ceramic is able to use for machinery or engine parts at elevated temperature.