FABRICATION OF Al7075/ ZrB2 SURFACE COMPOSITE VIA FRICTION STIR PROCESSING

Abstract

Friction stir processing is new surface modifying technique to fabricate surface composite layer. A specially designed rotating tool with shoulder and pin is plunged into the surface of material and then processed. The rotating tool pin causes intense plastic deformation of material due to stirring action. The processed region results in refined grain structure and uniform dispersion of reinforcement particles in the matrix. In this project work different volume of ZrB2 reinforcement particles inserted into the Al 7075 alloy and then processed by FSP. Fabricated surface composites were analyzed with microstructural, EDS and XRD studies. Mechanical and wear properties were also examined. To understand the wear and fracture mechanism of composite SEM study were also carried out .The results shows that composites are having higher mechanical and wear properties than the base material. Around 10 % increase in mechanical properties and more than 50% reduction in wear rate was observed. The higher volume content of ZrB2 particles exhibited higher tensile and wear properties compared to lower content of ZrB2 particles. However at higher content of ZrB2 particles there was marginal increase in tensile strength but great reduction in elongation.