In situ production of Fe-VC and Fe-TiC surface composites by cast-sintering

Using a new cast-sintering technique, iron-base surface composites reinforc ed by VC and TiC particles which were produced in situ and consisting of se lf-lubricant graphite and chromium-carbide, were sintered on the surface of cast steel during casting. The structure and composition of the surface co mposites were studied with the help of a SEM, an electron probe and XRD. Fr om the outside in of the iron-based surface composites, the concentration o f V and Ti was relatively stable and consistently retained a high level, wh ile the concentration of Cr and Ni took on a gradient distribution and decr eased gradually. The fine particles of VC and TiC measuring between 1 and 3 mum in diameter were uniformly dispersed in their matrices, and there was a perfect metallurgy-bond between the surface composite layer and the maste r-alloy. Under the condition of dry slipping with a heavy load, the Fe-VC a nd Fe-TiC surface composites offer virtually unique wear-resistance. (C) 20 01 Elsevier Science Ltd. All rights reserved.