NOVEL ALUMINA TITANIUM-CARBONITRIDE NICKEL COMPOSITES

Alumina-containing titanium-carbonitride nickel composites (Al2O3-TiCN-Ni-Mo2C) have been synthesized with up to 20 vol.% alumina particles and nickel con ten ts of 10-15 vol.%. Alumina in the form of platelets as well as powders have been successfully incorporated into the composites. The mechanical properties of these composites show a marked increase in toughness while retaining a good hardness and a low density when compared to TiCN-Ni cemented carbides. The presence of alumina with its superior chemical and wear resistance makes these composites very attractive for all wear parts-particularly for pieces exposed to chemically aggressive environments and high-temperature applications. Moreover, the complementary properties of these new composites (e.g., light weight, hardness, toughness, and chemical stability) allow a wide range of applications to be envisaged.