Manufacturing of Hard Composite Materials on Fe-Base with Oxide Particles

Abstract

Metal matrix composites (MMC) are often applied to tool surfaces to increase resistance to wear and tear. However, some matrix and particle materials such as Ni, Co, WC or TiC are expensive and partly classified as critical elements. With respect to tribo-mechanical properties, Fe-alloys reinforced with oxide particles are promising compound materials to produce wear-resistant MMC with low-cost and readily available materials. However, thus far the technical application of such MMCs is limited due to poor wettability of the oxides by Fe-base melts and an associated weak bonding between the oxide particles and the metal matrix phases. In this work two novel production techniques (namely pre-metallization and active sintering) are introduced, which improve the wettability and interfacial reactions between both materials and therefore enable supersolidus liquid-phase sintering (SLPS) of the MMC. For the first technique the oxide particles are pre-metallized by depositing a thin film of TiN on the surfaces. The second technique is called active sintering. For this technique the alloy design is adapted from active brazing, so that wettability of the oxide particles by the alloy-melt is increased. The resulting effects of these techniques are investigated using wetting and sintering experiments, and are analyzed with respect to the developed microstructures and interfacial reactions between the oxide particles and the metallic phases.