Steel binder cermets processed by combination of colloidal processing and powder metallurgy

Abstract

Cermets constituted by a high-speed steel matrix reinforced with 50 vol. % Ti(C,N) present a great potential due to its combination of properties, such as high wear and oxidation resistance, together with high values of hardness and toughness. However, the consolidation of these materials by conventional powder metallurgy processing presents two main problems: The agglomeration of Ti(C,N) particles, leading to nonhomogeneous microstructures, and the low compressibility of the blends due to the small size and morphology of the starting powders.In this work, colloidal techniques are proposed to overcome these issues. Aqueous suspensions of steel powders and Ti(C,N) particles are prepared followed by spray-dry to obtain spherical granules able to be processed by pressing and sintering, avoiding oxidation of powders. The agglomerates present higher compressibility than blends, and sintered materials show higher density and hardness.

Formation of Graphite Phase in Powder Metallurgical Ultrahigh Carbon Steels with High Wear Resistance

“…The oxygen contents do not show similar trend and are all lower than 0.30%. In comparison to the O content of typical PM materials, the produced UHCS have the similar oxygen contents . Therefore, we assume that the effects of O, N, and H on the microstructure and mechanical behavior of the UHSC in this work are marginal.…”

Influence of Milling and Use of Ni and Al Containing Metal Binder in NbC-Based Cermets

“…Additionally, WC/Co combination is considered a carcinogenic material to humans [5][6][7] . TiC or Ti(C,N) carbides with or without additions of other carbides were one of the explored in metal machining due to their high wear resistance [8][9][10][11] . Niobium carbides have been hardly used, although it was investigated in the sixties and seventies.…”