Friction stir processing

About: Friction stir processing is a research topic. Over the lifetime, 2977 publications have been published within this topic receiving 62158 citations.

Microstructural, mechanical and tribological behavior of aluminum nitride reinforced copper surface composites fabricated through friction stir processing route

Abstract: This work focuses on investigating the effect of Aluminum Nitride (AlN) for its 5, 10 and 15 vol% dispersion onto the surface of copper matrix through friction stir processing route. Microstructural observation confirms for the breaking down of grain size thus implying dynamic recrystallization process and also uniform dispersion along with good bonding of AlN particles with copper matrix. Hardness of the developed surface composite exhibits an increasing trend which is supposed to be the effect of dispersed particles and grain size reductions. Tensile tests prove that surface composites yields incremental behavior over strength with rise in AlN vol% even though values were far behind the strength offered by pure copper. Fractured surface micrograph of tensile specimens indicates reduction in ductility of the developed composite with dispersion of AlN particles. Wear resistance showcased a positive inclination with respect to reinforcement increments while the frictional coefficient value also possessed a propensity to increase. The fluctuation of frictional coefficient value diminished with AlN addition mainly because of reduced contact between copper and the rotating counterpart besides carrying away the exerted loads by these AlN particles. Detailed characterization of worn out surface prove that with AlN addition wear rate through adhesion has also reduced significantly.

On the Hardening of Friction Stir Processed Mg-AZ31 Based Composites with 5–20% Nano-ZrO2 and Nano-SiO2 Particles

Abstract: Mg-AZ31 based composites with 10{20 vol% nano-sized ZrO2 and 5{10 vol% nano-sized SiO2 particles were fabricated by friction stir processing (FSP). The clusters of the nano-ZrO2 and nano-SiO2 particles, measuring 180–300 nm in average, were relatively uniformly dispersed. The average grain size of the Mg matrixes of the composites varied within 2–4 mm after four FSP passes. No evident interfacial product between the ZrO2 particles and Mg matrix was found during the FSP mixing ZrO2 into Mg-AZ31. However, significant chemical reactions occurred at the Mg/SiO2 interface to form the Mg2Si phase. The mechanical responses of the resulting nano-composites in terms of hardness and tensile properties of these Mg/nano-ZrO2 and Mg/nano-SiO2 composites were examined and compared. The grain refinements and the corresponding hardening mechanisms are also analyzed and discussed. [doi:10.2320/matertrans.47.2942]

Wear Characteristics of Al5083 Surface Hybrid Nano-composites by Friction Stir Processing

Abstract: Friction stir processing (FSP) is used to produce surface composites with the retainment of bulk properties In the present study, FSP was utilized to incorporate nano particles of Boron carbide (B4C) and Titanium carbide (TiC) into the matrix of Al5083 alloy individually and in combined form in order to produce mono and hybrid surface composite layer The FSPed regions were analyzed through scanning electron microscope (SEM) and XRD studies Mechanical properties of the FSPed surface composites were evaluated through micro hardness and tensile tests Wear characteristics of the composites were evaluated through pin on disc dry sliding wear test at sliding speed of 1 m/s and under the normal load ranging from 20 to 100 N in steps of 20 N The mechanical and wear resistance properties of the composite were higher than the base alloy Among the processed composites, Al–B4C composites have exhibited the highest hardness and tensile strength However the hybrid composites (Al–B4C–TiC) have exhibited significant increase in wear resistance Worn out surfaces and wear debris were analyzed through SEM studies