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The present work is focused on ferrous powder metallurgy and presents some results of a development of a suitable masteralloy for use as an additive to iron powder for the production of sintered steels. The masteralloy was produced by melting a powder mixture containing approximately Fe + 20% Ni + 20% Mn + 20% Si + 1% C (wt%), in order to obtain a cast billet that was converted into fine powder by crushing and milling. It was observed presence of SiC in the masteralloy after melting that is undesirable in the alloy. Si element should be introduced by using ferrosilicon. Sintered alloys with distinct contents of alloying elements were prepared by mixing the masteralloy powder to plain iron powder. Samples were produced by die compaction of the powder mixtures and sintering at 1200 °C in a differential dilatometer in order to record their linear dimensional behaviour during heating up and isothermal sintering, aiming at studying the sinterability of the compacts. Microstructure development during sintering was studied by SEM, XRD and microprobe analyses.

In the development of dry self-lubricating composites, not only solid lubricant particle size and distribution are important, but also the correct selection of the solid lubricant characteristics, which should be stable, i.e. not reactive, during the whole processing. In this work, Fe+9 vol% h-BN composites were produced by uniaxial cold compaction and sintering, for which a reaction between h-BN and iron was detected after sintering at 1,150°C. The reaction phase was characterized by optical and scanning electron microscopy and identified by X-ray diffraction and energy-dispersive X-ray spectroscopy. The newly formed phase had high hardness when compared with the iron matrix. The resulting composites presented a high friction coefficient and high wear.