DEVELOPMENT r OF IRON BASED COMPOSITES CONTAINING ALLOY CARBIDES

Abstract

Present investigation has been carried out to develop iron based composite containing carbide bysolidification processing. Commercial Fe-TiC composites are available under trade name `Ferro-Tic' which is prepared by relatively expensive powder metallurgy technique. Literature review on the properties of composite reveals that titanium carbide is a superior carbide for the purpose of imparting low friction and high wear resistance. Earlier investigations have limited carbide loading in Fe-TiC composites developed by foundry technique to 15 volume percent but the present investigation has enhanced carbide content in the composite to 25 volume percent which is the lower limit of carbide content in commercial product. The melt containing 20 and 25 volume percent of carbide has adequate fluidity for satisfactory- casting. The microstructure of cast composites reveals a ferrite pearlite matrix containing rounded titanium carbide. In addition intermetallic FeTi are also observed but its amount is lower in the composite containing higher amount of carbide. The hardness of composite containing 20 or 25 volume percent of carbide is around 550 VHN which is in the range of commercial Ferro-Tic material. The Archard's wear resistance of composites containing higher amounts of carbide are 3431 and 3689 for 20 and 25 volume percent of carbide and it is superior to 3145 which has been observed in composite containing 15 volume percent of carbide.