Slip Casting of Ferrous Matrix-Ti(CN) Cermets. Comparison of the Colloidal Behavior between Fe and Stainless Steel

摘要

Ferrous matrix cermets are an interesting alternative to the conventional Co and Ni matrixes due to the lower cost and toxicity. The conventional processing of parts by dry pressing and sintering provides materials with coarse microstructures as no good dispersion is achieved if any of the particles presents sizes around the micron. In this work alternative route is presented involving colloidal processing of the metallic and ceramic powders in water and further shaping by slip casting of the studied slurries. Colloidal processing, normally used for ceramic materials, permits the packing of fine powders improving the homogeneity of mixtures and allowing an accurate control over the final microstructure. The objective of this work is to compare the colloidal behavior of Fe and 430L stainless steel powders aiming the processing of cermet. The chemical and colloidal stability of these powders in aqueous media are optimized as well as the Theological behavior of the slurries. In a similar way suspensions of Ti(CN) particles are prepared to obtain the final slurry with the composition of the cermet that is processed by slip casting, which appears as a feasible option of processing for steels and ferrous based cermets.