SURFACE COMPOSITE FABRICATION OF CARBON STEEL VIA FRICTION STIR PROCESSING

Abstract

Fabrication of metal matrix composites (MMCs) with improved mechanical properties and modified microstructures has attracted many attentions. One of the novel methods to produce MMCs is friction stir processing (FSP). FSP is a method of changing the properties of metal through intense, localized plastic deformation. This deformation is produced by inserting a non-consumable tool into the workpiece, and revolving the tool in a stirring motion as it is pushed laterally through the workpiece. Friction between the shoulder and work piece results in localized heating which raises the temperature of the material to the range where it is plastically deformed. During this process, severe plastic deformation occurs and due to thermal exposure of material, it results in a significant evolution in the local microstructure. The present work aims the fabrication of a Steel/TiCanano composite by introduction fantasized TiC powder into the stir zone. The fabricated nano composite layer exhibited micro hardness value of ~ 320HV. This is greater than 235 HV of the friction stir processed layer without adding of TiC powder. In addition, aasignificantaimprovement in wear resistance of the nanocomposite layer was observed. The properties of the surface composite are attributed due to the uniform dispersion of hard TiC reinforcements in a matrix of Ultra fine dynamically recrystallized grains.