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.

Fastener for attachment by friction stir processing

Abstract: A fastener is provided for attachment to a workpiece by a friction stir process. The fastener includes a base having an underside adapted to seat upon the workpiece and a fastener portion attached to the top side of the base. An anchor portion projects from the underside of the base and is adapted to be rotated and advanced at high speed and inserted into the workpiece by friction stirring of the workpiece. The anchor portion is embedded in the workpiece upon cooling of the workpiece. The anchor portion has an indent in the surface thereof enabling the softened stirred material to flow into the indent and thereby mechanically capture the anchor portion within the solidified workpiece.

Microstructure and Texture Evolution during Single- and Multiple-Pass Friction Stir Processing of Heat-Treatable Aluminum Alloy 2024

Abstract: Microstructure and crystallographic texture evolution during single- and multiple-pass friction stir processing (FSP) of an age-hardenable aluminum alloy 2024 (Al-Cu-Mg) was investigated. Multiple-pass experiments were carried out using two different processing strategies, multi-pass FSP, and multi-track FSP. Effect of a post-FSP heat treatment above and below the solutionizing temperature of the alloy was also studied. FSP experiments were carried out using an optimal set of parameters. Characterization tools used in the study include scanning electron microscopy (SEM), electron back-scattered diffraction (EBSD), electron probe micro-analyser (EPMA), and X-ray diffraction (XRD). Microstructural features indicate the occurrence of particle stimulated nucleation (PSN) assisted dynamic recrystallization (DRX) as the dominant microstructural evolution mechanism in the nugget zone. Geometrical coalescence occurred, leading to the formation of some larger grains in the nugget zone. Heterogenous micro-texture distribution was observed in the nugget zone with the bulk textures consisting of FCC shear texture components dominated by A (1)*/A (2)* and C. Microstructure and texture in the nugget zone remained stable after both routes of multiple-pass processing, demonstrating the possibility of FSP to produce bulk volume of fine-grained materials. Post-FSP heat treatment indicated the stability of microstructure and texture up to 723 K (450 A degrees C) owing to relatively lower strain energies retained after FSP.

Experimental investigation of Mg/SiC composite fabrication via friction stir processing

Abstract: Friction stir processing has recently emerged as an effective alternative method for fabricating metal matrix composites. This paper presents an experimental investigation on the feasibility of using friction stir processing for fabricating Mg/SiC surface composites. The effects of the processing parameters, such as the rotational and translational speeds, and the groove geometry on the prepared composites have been examined. The thermal profiles, microstructure, and microhardness of the processed materials have been analyzed. The Mg/SiC surface composite was successfully fabricated using friction stir processing. A significant increase in the microhardness was attained within the stir zone due to grain refinement and the addition of SiC particles.

Experimental and ANOVA analysis on tribological behavior of Al/B4C micro and nanocomposite

Abstract: An investigation was undertaken to analyse the effect of addition of micro- and nano-boron carbide particles for the synthesis of Al/B4C nanocomposite (and micro/ nearing nano) using gravitational friction stir processing and to analyse the influence of normal load sliding wear and frictional behaviour of the composite. The normal load was varied from 20 to 40 N and the sliding distance was varied from 1 to 3 km. The sliding wear behaviour was evaluated using a pin-on-disc experimental set-up. Scanning electron microscopy was used to investigate the microstructure of the fabricated Al/B4C nanocomposites. The result showed that Al/B4C nanocomposite exhibited less coefficient of friction and more wear rate when compared to Al/B4C microcomposite. The predominant wear mechanisms observed were abrasive and adhesive during the test.

Superplastic Forming of 7475 Al Sheet after Friction Stir Processing (FSP)

Abstract: Since the invention of Friction Stir Welding (FSW) in 1991, an increasing number of successful applications have been found for this unique solid-state welding technique. More recently, attention has been given to utilizing the mechanics of friction stirring to thermo-mechanically modify the microstructure of aluminum alloys to create or enhance superplasticity. Until now, superplasticity induced by friction stir processing (FSP) has only been demonstrated in small samples and evaluated by hot tensile elongation testing. The present work describes what we believe to be the first biaxial testing and full size component superplastic forming of friction stir processed aluminum sheet. The remarkable formability demonstrated in these ‘first time’ trials is described in detail.