Processing and Mechanical Properties of B₄C/Diamond Impregnated Fe/Co MMC

Cobalt is currently used in the production of diamond reinforced metal matrix composites (i.e. stone-cutting tools). Herein, how sintering temperature and matrix composition influences the material properties of diamond reinforced MMCs was explored. The aim of this work is to produce diamond reinforced metal matrix composites based on Fe-Co compositions with and without B₄C are processed by a PM method using a hot pressing technique. The effects of Fe and B₄C additions on the characteristic of diamond impregnated Co matrix composites have been investigated. Samples reinforced with and without B₄C having two different compositions (different Fe/Co ratio) were produced under 25 MPa pressure and sintered at 1000°C temperature. After sintering, hardness tests were carried out and wear tests were performed by pin-on-disc. The results showed that addition of Fe caused slightly decrease in the hardness of the matrix. However, reinforcing with B₄C increased the hardness of the matrix. It is observed that wear resistance of B₄C reinforced Fe-Co metal matrix composite was greater than that of composites without reinforcement. SEM and EDX techniques were used to characterize the composites.