Showing papers on "Friction stir processing published in 2017"
TL;DR: Friction stir welding (FSW) has achieved remarkable success in the joining and processing of aluminium alloys and other softer structural alloys, however, it has not been entirely successful in the manufacturing of different desired materials essential to meet the sophisticated green globe requirements as discussed by the authors.
347 citations
TL;DR: In this article, the phase transformation and superelasticity in TiNbTaZr alloy prepared by friction stir processing (FSP) were investigated systematically, and a multiple-pass FSP with a 100% accumulated overlap to three passes was implemented.
154 citations
TL;DR: In this paper, the current status of in-situ AMMCs fabrication through FSP technique is discussed and a review and summarization of various systems of AMMC fabrication such as Al Transition metals (TM), Al- Metal oxides (MO), and Al- Salt reaction systems, at various operating conditions and FSP parameters and their effects on resultant microstructure and final properties.
135 citations
TL;DR: In this article, the current understanding and development of friction-stir welding and processing of Ti-6Al-4V alloy are briefly reviewed, focusing on microstructural aspects and microstructure-properties relationship.
124 citations
TL;DR: This work presents a strong and ductile non-equiatomic HEA obtained after friction stir processing (FSP), which results in synergistic strengthening via TRIP, grain boundary strengthening, and effective strain partitioning between the γ and ε phases during deformation, thus leading to enhanced strength and ductility of the TRIP-assisted dual-phase HEA engineered via FSP.
Abstract: The potential of high-entropy alloys (HEAs) to exhibit an extraordinary combination of properties by shifting the compositional regime from the corners towards the centers of phase diagrams has led to worldwide attention by material scientists. Here we present a strong and ductile non-equiatomic HEA obtained after friction stir processing (FSP). A transformation-induced plasticity (TRIP) assisted HEA with composition Fe50Mn30Co10Cr10 (at.%) was severely deformed by FSP and evaluated for its microstructure-mechanical property relationship. The FSP-engineered microstructure of the TRIP HEA exhibited a substantially smaller grain size, and optimized fractions of face-centered cubic (f.c.c., γ) and hexagonal close-packed (h.c.p., e) phases, as compared to the as-homogenized reference material. This results in synergistic strengthening via TRIP, grain boundary strengthening, and effective strain partitioning between the γ and e phases during deformation, thus leading to enhanced strength and ductility of the TRIP-assisted dual-phase HEA engineered via FSP.
124 citations
TL;DR: In this article, the effect of using different number of passes on the microstructure, microhardness, tensile and wear properties of the specimens was investigated and it was found that iteration of FSP consistently improves tensile properties and micro-hardness of the materials.
109 citations
TL;DR: In this paper, a multi-pass friction stir processing (FSP) was employed for the first time to disperse graphene in the form of graphene nano-platelets (GNPs) into an AA5052 aluminum-magnesium alloy to fabricate a new Al-Mg/3.vol% GNPs nanocomposite.
106 citations
TL;DR: In this paper, the effects of pin profiles on the superplastic behavior of FSP tools were investigated. But the results were limited to three different polygonal pin profiles of square, pentagon and hexagon.
104 citations
TL;DR: In this paper, the effect of friction stir processing (FSP) on the pitting corrosion and the intergranular attack of 7075 aluminum alloy was investigated, and three friction stir processed samples were produced by employing a constant tool travel speed of 100mm/min at the rotating speeds of 630, 1000 and 1600 rpm.
92 citations
TL;DR: In this article, the authors used molybdenum (Mo) as potential reinforcement for aluminum matrix composites produced using friction stir processing (FSP) to improve ductility.
92 citations
20 Jun 2017-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper, a multi-step friction-stir processing (FSP) was employed to fabricate an ultra-fine grained (UFG) Al-matrix nanocomposite with simultaneously enhanced indentation hardness and tensile properties.
Abstract: In this study, multi-step friction-stir processing (FSP) was employed to fabricate an ultra-fine grained (UFG) Al-matrix nanocomposite with simultaneously enhanced indentation hardness and tensile properties For this aim, about 35 vol% of SiC nanoparticles were incorporated within an Al-Mg alloy matrix by applying up to five cumulative overlapping FSP passes Dispersion of nanoparticles at the stirred zone (SZ) and their interfaces with the aluminum matrix were studied by using scanning and electron backscattered electron microscopy The results showed that the grain and sub-grain structures of the SZ were refined down to about 14 µm and less than 1 µm respectively, as a result of dynamic recrystallization (DRX) during FSP The distribution of grains and their orientations was significantly affected by the presence of SiC nanoparticles during FSP SiC nanoparticles provided both direct and indirect influences on the strengthening of Al-matrix based on the Orowan looping and grain refinement mechanisms, respectively The morphology and distribution of precipitates were both broken down and partially dissolved during FSP as well The processed UFGed nanocomposite exhibited drastically improved hardness, yield stress (YS) and ultimate tensile strength (UTS) by up to ~140%, 75% and 60%, respectively, as compared to the annealed Al-Mg alloy Fractographic features revealed a combined ductile-brittle rupture behavior, while the ductile portion was more significant and preserved the elongation of nanocomposite up to about 30% Finally, the tensile flow behavior of the processed nanocomposite was described using a dislocation-based model which suggests that grain boundary strengthening is the dominant mechanism involved
TL;DR: In this paper, local stirring using a friction stir processing (FSP) tool is shown to very significantly increase the fracture strain of the Al alloy 6056 sometimes by more than a factor of two while making it more isotropic.
TL;DR: In this article, a novel process for preparing carbon nanotubes (CNTs) reinforced magnesium nanocomposites was developed, which combined friction stir processing (FSP) and ultrasonic assisted extrusion.
TL;DR: In this paper, Tungsten carbide, cobalt chromium, chromium carbide and aluminium oxide coatings were successfully cold spray deposited on AA5083 grade aluminium and then friction stir processed to embed the particles in the substrate in order to generate a metal matrix composite surface layer.
TL;DR: The in-situ grain structure and texture evolution during the whole process of friction stir welding (FSW) are clarified in this paper, where the authors show that as material in MFZ rotated around the probe, the fraction of low-angle grain boundaries (LAGBs) was reduced, the ratio of twin boundaries increased and the grain size distribution became wider, while the average grain size was fairly constant despite the increase in strain.
TL;DR: In this article, the authors investigated the mechanisms of simultaneous improvement of tensile properties, wear properties and corrosion resistance of stir cast Al7075-2 ¾wt.% SiC micro-and nanocomposites through microstructural refinement by friction stir processing (FSP).
TL;DR: In this article, the effect of tool plunge depth on pattern of reinforcement particles dispersion in metal matrix was investigated and six varying tool plunge depths were chosen at constant levels of shoulder diameter and tool tilt angle to observe the exclusive effect of plunge variation.
TL;DR: In this paper, the authors report the production and characterization of AA6061/18 vol% RHA AMC using the novel method friction stir processing (FSP), and the microstructure was studied using optical microscopy, scanning electron microscopy (SEM), and electron back scattered diagram (EBSD).
TL;DR: In this paper, a Mg 6Zn 1Y 0.5Zr casting was subjected to friction stir processing (FSP), which resulted in remarkable grain refinement, dissolution and dispersion of intergranular eutectic I-phase networks and strong basal texture.
08 Feb 2017-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this article, an attempt was made to reinforce stainless steel (SS) particles to prepare AA6082/(0,6,12 and 18vol%) SS AMCs via friction stir processing (FSP).
Abstract: Aluminum matrix composites (AMCs) reinforced with various ceramic particles usually exhibit poor ductility. One solution to increase ductility is the usage of hard metallic or alloy particles as reinforcements. An attempt was made to reinforce stainless steel (SS) particles to prepare AA6082/(0,6,12 and 18 vol%) SS AMCs via friction stir processing (FSP). SS particles were effectively embedded in the aluminum matrix in its alloy form without any detrimental interfacial reaction. The distribution of SS particles in the composite was fairly homogenous. All regions inside the stir zone were filled with SS particles. The composite showed equiaxed fine grains due to dynamic recrystallization and pinning effect. The incorporation of SS particles enhanced the tensile strength of the composites without sacrificing ductility. A network of well developed dimples was observed on the fracture surfaces of the composites ensuring ductility.
TL;DR: The results revealed that multi-pass FSP causes a homogeneous distribution and good dispersion of Al2O3 in the metal matrix, and consequently an increase in the hardness of the matrix composites.
Abstract: In the present work, an aluminum metal matrix reinforced with (Al2O3) nanoparticles was fabricated as a surface composite sheet using friction stir processing (FSP). The effects of processing parameters on mechanical properties, hardness, and microstructure grain were investigated. The results revealed that multi-pass FSP causes a homogeneous distribution and good dispersion of Al2O3 in the metal matrix, and consequently an increase in the hardness of the matrix composites. A finer grain is observed in the microstructure examination in specimens subjected to second and third passes of FSP. The improvement in the grain refinement is 80% compared to base metal. The processing parameters, particularly rotational tool speed and pass number in FSP, have a major effect on strength properties and surface hardness. The ultimate tensile strength (UTS) and the average hardness are improved by 25% and 46%, respectively, due to presence of reinforcement Al2O3 nanoparticles.
TL;DR: In this article, the friction stir processing (FSP) was applied to fabricate a nanosized composite layer of TiO2 and Ti-6Al-4V.
14 Mar 2017-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this article, 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 was investigated.
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.
TL;DR: In this paper, FSP was utilized to incorporate nano particles of Boron carbide and Titanium carbide into the matrix of Al5083 alloy individually and in combined form in order to produce mono and hybrid surface composite layer.
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
TL;DR: An innovative hybrid process combining two very effective solid-state techniques which are cold spray (CS) and Friction Stir Processing (FSP) was proposed to fabricate a high-strength ultrafine-grained Cu Zn coating as mentioned in this paper.
TL;DR: In this article, the role of grain refinement and distributed hard nanoparticles on the tribological behavior of AA5052 Al-Mg alloy under dry sliding wear condition was evaluated.
Abstract: Reactive friction stir processing (RFSP) has been employed to modify the surface properties of AA5052 Al-Mg alloy through grain refinement and the distribution of ultrafine hard nanoparticles (2 to 6% volume fractions of 50 nm titanium dioxide). The heat generated induced solid state reactions between the metal matrix and the reinforcement to form Al3Ti/MgO inclusions. The role of grain refinement and distributed hard nanoparticles on the tribological behavior of the alloy under dry sliding wear condition was evaluated. The wear rates and friction coefficient as well as macro- and micro-features of the worn surfaces indicate that the wear mechanism (at 3–7 kgf and 0.5 m/s) is abrasive. The wear rate decreased with increasing volume fraction of the hard inclusions with a significant reduction in the friction coefficient. The wear resistance could be improved > 125% (compared with the annealed alloy) at 6 vol% TiO2. The relations between the enhanced wear resistances, the microstructural changes and mechanical properties have been characterized.
TL;DR: In this article, the influence of the Y form (eutectic phase and solute) on microstructural evolution of as-cast and solid solution Mg-Zn-Y-Zr alloys during friction stir processing (FSP) is studied.
TL;DR: In this article, the cold gas dynamic spraying (CGDS) process was employed to modify the surface of AZ31B magnesium alloy with an aluminum-zinc alloy (AA7075).
Abstract: In this study, the cold gas dynamic spraying (CGDS) process was employed to modify the surface of AZ31B magnesium alloy with an aluminum-zinc alloy (AA7075). Friction-stir processing (FSP) was subsequently applied as a solid-state localized surface modification technique to improve the structure and integrity of the cold sprayed layer, by enhancing densification, homogeneity, and microstructural features of the as-deposited material. The structure of precipitates and grains were also refined due to the applied severe plastic deformation during FSP, which ultimately affects the indentation hardness resistance of the processed AZ31B-AA7075 bi-metallic structure. Microscopy indicated slight grain coarsening within the AZ31B substrate occurred simultaneously with refinement of the AA7075 coating, along with significant hardness improvements of ~ 80% and 30% respectively for each region in terms of Vickers hardness after FSP.
TL;DR: In this paper, a fine-grained aluminum matrix hybrid nanocomposite was fabricated by reactive friction-stir processing (FSP) of an Al-Mg alloy containing about 2.5 vol% of embedded multi-walled carbon nano-tubes (MW-CNTs).