Investigation on the micro-structure and mechanical properties of copper based surface composites fabricated by friction stir processing

Abstract

Copper is familiar for its electrical and thermal properties and these are considered only after addressing the mechanical properties. This contrary characteristic of copper was determined to a considerable extent with the dispersion of suitable ceramics thus yields high hardness; wear resistance and toughness to a considerable extent without forfeiting the electrical and thermal properties. A surface composite of copper reinforced with varying volume fractions of SiC and h-BN micro particles through Friction Stir Processing is fabricated. Based on volume fractions (6%, 12%, 18%) groove width was varied with depth as 1.5 mm and compacted with 100% SiC, 100% h-BN, 50% SiC + 50% h-BN. A single pass FSP was done using a tool with rotational speed of 900 rpm, travel speed of 40 mm/min and an axial force of 5 kN. High hardness can be achieved and improved with the dispersion of 18 vol% SiC particles compared to the dispersion of h-BN particles and other vol%.