Showing papers on "Friction stir processing published in 2010"
TL;DR: In this paper, a mixture of SiC and Al2O3 powders of different weight ratios was packed into a groove of 3mm width and 1.5mm depth cut on the aluminum plate, and covered with an aluminum sheet 2mm thick.
215 citations
TL;DR: In this article, the effect of process parameters such as rotational and traverse speeds, tool penetration depth and tilt angle on the formation of defects such as cracks, tunnelling cavity and also on sticking of matrix material to the tool was investigated.
Abstract: Friction stir processing (FSP) was used to fabricate SiC/AZ91 composite layer. Effect of process parameters such as rotational and traverse speeds, tool penetration depth and tilt angle on the formation of defects such as cracks, tunnelling cavity and also on sticking of matrix material to the tool was investigated. Also, effect of these parameters was studied on the mechanical properties and microstructures of specimens. Microstructure studies were carried out by optical and SEM. Results showed that FSP is an effective process to fabricate SiC/AZ91 composite layer with uniform distribution of SiC particles, good interfacial integrity and significant grain refinement. Increasing the rotational speed leads to a decrease in the grain size and an increase in the traverse speed leads to a decrease in the grain size. There are upper and lower limitations for these speeds which were determined. PD is a more effective parameter to produce sound surface layer. PD value was affected by traverse and rotational speeds and the tilt angle values. This study shows that by using 5 μm SiC particles, the stir zone grain size reduces from 150 to 7.17 μm and stir zone hardness increases from 63 to 96 Hv.
176 citations
TL;DR: In this article, the microstructures and compositions of the composites were analyzed, the hardness and tensile properties of intermetallics were measured, and a defect-free composites with Al3Ni and Al-3Ni2 were successfully produced by FSP and heat treatment.
155 citations
TL;DR: In this article, the surfaces of cast A319 alloy plates of nominal composition (wt.%): Al 5.2 Si 2.51 Cu were subjected to single stir Friction Stir Processing (FSP) with a view to decreasing the grain size and porosity level and improving the mechanical properties.
125 citations
TL;DR: In this paper, a superplastic deformation mechanism map for FSP aluminum alloys is proposed, which reveals the presence of threshold stress, a stress exponent of 2, an inverse grain size dependence of 2 and an activation enemy of 142 kJ mol(-1).
123 citations
25 Sep 2010-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper, a new approach was used to produce Al-10%Al2O3 surface nanocomposite on Al2024 substrate, which involved air plasma spraying of Al−10% Al 2O3 powder on substrate.
Abstract: A new approach was used to produce Al–10%Al2O3 surface nanocomposite on Al2024 substrate. This novel approach involved air plasma spraying of Al–10%Al2O3 powder to produce Al–10%Al2O3 coating on substrate. The coated material was then subjected to friction stir processing (FSP) to distribute Al2O3 particles into the substrate. Microstructure and mechanical properties of samples were investigated by optical microscopy (OM), scanning electron microscopy (SEM), micro-hardness and wear measurements. As a result, it was found that the Al2O3 particles were distributed uniformly inside the substrate with an average penetration depth of about 600 μm. The surface nanocomposites produced in this way had excellent bonding with the substrate. The micro-hardness of the surface nanocomposite was ∼230 Hv, much higher than ∼90 Hv for Al2024 substrate. The surface nanocomposites also exhibited lower friction coefficient and wear rate. It was found that the addition of Al2O3 nanoparticles to the Al2024 matrix alloy affect the mechanism of wear.
122 citations
25 Jul 2010-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this article, the microstructure of AA5052 was characterized using electron back scattered diffraction to obtain the boundary spacing, the fraction of high angle boundaries and to estimate the dislocation density from local misorientations.
Abstract: The mechanical behavior of ultrafine grained AA5052 processed through different techniques—rolled, annealed, friction stir processed (FSP) and equal channel angular pressed (ECAP)—were compared and correlated with microstructure. The microstructure was characterized using electron back scattered diffraction to obtain the boundary spacing, the fraction of high angle boundaries and to estimate the dislocation density from local misorientations. Both FSP and ECAP conditions had ultrafine boundary spacing, but the fraction of high angle boundaries was larger for the FSP condition. Tensile deformation carried out at 297 K and 10−3 s−1 showed a lower work-hardening rate and recovery rate for FSP as compared to the ECAP condition. It was inferred that low angle boundaries are more effective sinks for dislocations. When comparing differently processed materials, the strength, ductility and work-hardening behavior correlate better with the fraction of high angle boundaries than the boundary spacing.
119 citations
TL;DR: Friction-stir processing (FSP) was adopted to modify the microstructure of a cast Cu-9Al-4.5Ni-4Fe NiAl bronze alloy.
117 citations
TL;DR: Nickel particulate reinforced aluminium matrix composite was processed without formation of deleterious Al 3 Ni intermetallic by friction stir processing (FSP), which resulted in uniform dispersion of nickel particles in the aluminium matrix with excellent interfacial bonding and also lead to grain refinement of the matrix as mentioned in this paper.
107 citations
TL;DR: In this article, a review of friction stir processing (FSP) technology and its application for microstructure modification of particle reinforced composite materials is provided. But the main focus of FSP was on aluminum based alloys and composites.
Abstract: The objective of this article is to provide a review of friction stir processing (FSP) technology and its application for microstructure modification of particle reinforced composite materials. The main focus of FSP was on aluminum based alloys and composites. Recently, many researchers have investigated this technology for treating other alloys and materials including stainless steels, magnesium, titanium, and copper. It is shown that FSP technology is very effective in microstructure modification of reinforced metal matrix composite materials. FSP has also been used in the processing and structure modification of polymeric composite materials. Compared with other manufacturing processes, friction stir processing has the advantage of reducing distortion and defects in materials. The layout of this paper is as follows. The friction stir processing technology will be presented first. Then, the application of this technology in manufacturing and structure modification of particle reinforced composite materials will be introduced. Future application of friction stir processing in energy field, for example, for vanadium alloy and composites will be discussed. Finally, the challenges for improving friction stir processing technology will be mentioned.
104 citations
TL;DR: In this article, a commercial 5083 Al rolled plates were subjected to friction stir processing (FSP) with a tool rotational speed of 430rpm and a traverse feed rate of 90mm/min.
TL;DR: In this article, a superplastic elongation of 210% was obtained at 175 degrees C, and the optimum strain rate and maximum elongation increased with increasing temperature, indicating that the GBS contribution to the strain exceeded 50% at 175 degree C and increased with increases in strain and temperature.
TL;DR: In this paper, a nano-ceramic particle reinforced composite coating was created by incorporating Al2O3 ceramic particles into the surface of AA6061-T6 alloy plate with multiple pass friction stir processing (FSP).
Abstract: Nano ceramic particle reinforced composite coatings were created by incorporating Al2O3 ceramic particles into the surface of AA6061-T6 alloy plate with multiple pass friction stir processing (FSP). Optical microscopy and Micro-Vickers hardness tests were employed to investigate the influence of axial force and the number of FSP pass on the distribution of the ceramic particles and the hardness of the generated nano ceramic particle reinforced composite coating. Results show that the composite coating is as deep as the length of the pin probe. No distinct interface was developed between the coating and the base metal. The composite region becomes greater as the axial force and the number of FSP pass increased. At the same time, the distribution of the ceramic particles became more homogeneous. Nano particles in the coating have no significant effect on the macro-hardness of AA6061-T6 aluminum alloy even in the composite zone due to the softening of matrix material resulted from overaging. Spindle torque of the tool increased with increasing axial force, while it became less variable and smaller in subsequent pass compared to that in the first pass.
TL;DR: In this article, the effect of the tool rotating rate on the porosity and morphology of the pores was investigated and the results indicated the minimum necessary amount of stirring action and will provide a guideline for improving productivity.
TL;DR: In this article, a five times improvement in fatigue life of an investment cast Al-7Si-0.6mg hypoeutectic alloy was reported due to the closure of casting porosities.
TL;DR: In this article, single pass friction stir processing (FSP) was used to increase the mechanical properties of a cast Mg-Zn-Zr-rare earth (RE) alloy, Elektron 21.
Abstract: Single-pass friction stir processing (FSP) was used to increase the mechanical properties of a cast Mg-Zn-Zr-rare earth (RE) alloy, Elektron 21. A fine grain size was achieved through intense plastic deformation and the control of heat input during processing. The effects of processing and heat treatment on the mechanical and microstructural properties were evaluated. An aging treatment of 16 hours at 200 °C resulted in a 0.2 pct proof stress of 275 MPa in the FSP material, a 61 pct improvement over the cast + T6 condition.
TL;DR: In this paper, the influence of strain rate and temperature during friction stir processing (FSP) on the texture and tensile behavior of a Mg alloy has been investigated by varying key processing parameters systematically, i.e. rotation and travel rates of the tool.
TL;DR: In this article, a new processing technique, friction stir processing (FSP), was applied to Al2024-T4 as a means to enhance the near-surface material properties, including micro-hardness and wear resistance.
TL;DR: In this paper, SiC particles were added to as-cast AZ91 magnesium alloy and nano-grain structure was produced via friction stir processing (FSP), and the effects of process parameters, such as the rotational and traverse speeds, the FSP pass numbers and the rotation direction of FSP tool on the powder distribution pattern, microstructure, and microhardness of the developed surface were investigated.
Abstract: In this investigation SiC particles were added to as-cast AZ91 magnesium alloy and AZ91/SiC surface nanocomposite layer with nano-grain structure was produced via friction stir processing (FSP). Effects of process parameters, such as the rotational and traverse speeds, the FSP pass numbers and the rotational direction of FSP tool on the powder distribution pattern, microstructure, and microhardness of the developed surface were investigated. Results show that the nanocomposite layer presents higher hardness, ultrafine grains, and better homogeneity. Increasing the rotational speed increases the grain size and decreases the microhardness of the layer. Conversely, the grain size decreases by increasing the traverse speed, while the microhardness of the layer increases. Additionally, increasing FSP pass numbers leads to better distribution of nanosized SiC particles in the AZ91 matrix, refined grains, and higher hardness. Changing tool rotating direction results in higher uniform distribution of SiC particle...
TL;DR: In this article, a magnesium alloy AZ31B was friction stir processed by using single and multiple pass FSP and the tensile anisotropy in the friction-stir-processed magnesium alloy was found to originate from the textured microstructure that evolved during FSP.
Abstract: Friction stir processing (FSP) improves the mechanical properties of metallic materials. In this study, a magnesium alloy AZ31B was friction stir processed by using single and multiple pass. The friction-stir-processed magnesium alloy exhibits higher tensile strength and ductility in the transverse direction (TD) compared to the longitudinal direction (LD). Both single pass and multiple (two) pass friction-stir-processed material show similar anisotropy in tensile properties, but the multiple pass friction-stir-processed material shows fine-grained microstructure with higher tensile strength and ductility. The tensile anisotropy in the friction-stir-processed AZ31B originated from the textured microstructure that evolved during FSP.
25 Nov 2010-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper, the effects of process parameters and friction stir processing (FSP) run configurations on the stability of nugget microstructure at elevated temperatures were evaluated and compared with other published results and AGG models.
Abstract: The effects of process parameters and friction stir processing (FSP) run configurations on the stability of nugget microstructure at elevated temperatures were evaluated. Cast plates of an Al–7Si–0.6Mg alloy were friction stir processed using a combination of tool rotation rates and tool traverse speeds. All single pass runs showed some extent of abnormal grain growth (AGG), whereas multi-pass runs were more resistant to AGG. Additionally, higher tool rotation rate was found to be beneficial for controlling AGG. These effects were analyzed by comparing the result of this work with other published results and AGG models.
01 Jan 2010
TL;DR: Friction stir welding (FSW) is a new welding process that has led to many worldwide applications, predominantly in the fabrication of aluminium components and panels as mentioned in this paper, and it has been used extensively in the automotive industry for high volume production of components, e.g. light alloy wheels and fuel tanks.
Abstract: Friction stir welding (FSW) is a patented new welding process that has had led to many worldwide applications, predominantly in the fabrication of aluminium components and panels. Trendsetters were the Scandinavian aluminium extruders for the manufacture of hollow aluminium deep freezer panels and for ship decks. The railway rolling stock industry uses FSW for the production of large prefabricated aluminium panels, which are made from aluminium extrusions. In the aerospace industry, large tanks for satellite launch vehicles are being produced by FSW from high-strength aluminium alloys, and several companies manufacture lightweight aluminium airframe structures for commercial and military aircraft. The automotive industry uses FSW now in the high-volume production of components, e.g. light alloy wheels and fuel tanks.
TL;DR: In this paper, friction stir processing (FSP) was applied to produce aluminum-based in-situ composites from powder mixtures of Al-5 mol pct CeO2.
Abstract: Friction stir processing (FSP) was applied to produce aluminum-based in-situ composites from powder mixtures of Al-5 mol pct CeO2. A billet of powder mixtures was prepared using the conventional pressing and sintering route. The sintered billet was then subjected to multiple passages of FSP. This technique has combined the hot-working nature of FSP and the exothermic reaction between Al and CeO2. The reinforcing phases were identified as Al11Ce3 and δ*-Al2O3. The Al2O3 particles with an average size of ~10 nm are uniformly distributed in the aluminum matrix, which has an average grain size of approximately 390 to 500 nm. Both the sintering temperature and the tool traversing speed used in FSP have significant influence on the microstructure and mechanical properties of the composite. The composite produced by sintering at 833 K followed by FSP with a tool traversing speed of 30 mm/min possesses an enhanced modulus (E = 109 GPa) and strength (ultimate tensile strength (UTS) = 488 MPa) as well as a tensile ductility of ~3 pct.
Journal Article•
TL;DR: In this article, the modification of a thermally sprayed cemented carbide (WC-CrC-Ni) layer by friction stir processing (FSP) was studied and the defects in the cemented carbers were removed and the hardness of the carbers increased to ∼ 1.5 times higher than that of the as-sprayed carbers.
Abstract: The modification of a thermally sprayed cemented carbide (WC–CrC–Ni) layer by friction stir processing (FSP) was studied. The cemented carbide layer was successfully modified using a sintered cemented carbide (WC–Co) tool. The defects in the cemented carbide layer disappeared and the hardness of the cemented carbide layer increased to ∼ 2000 HV, which was about 1.5 times higher than that of the as-sprayed cemented carbide layer. Additionally, the cemented carbide layer was bonded to the SKD61 (Nominal composition: 0.35–0.42 mass% C, 0.8–1.2 mass% Si, 0.25–0.5 mass% Mn, 4.8–5.5 mass% Cr, 1.0–1.5 mass% Mo, 0.8–1.2 mass% V, balance Fe) substrate by diffusion of the metallic elements and the distortion of the coating–substrate interface producing a mechanical interlocking effect.
TL;DR: In this paper, the modification of a thermally sprayed cemented carbide (WC-CrC-Ni) layer by friction stir processing (FSP) was studied and the defects in the cemented carbers were removed and the hardness of the carbers increased to ∼ 1.5 times higher than that of the as-sprayed carbers.
Abstract: The modification of a thermally sprayed cemented carbide (WC–CrC–Ni) layer by friction stir processing (FSP) was studied. The cemented carbide layer was successfully modified using a sintered cemented carbide (WC–Co) tool. The defects in the cemented carbide layer disappeared and the hardness of the cemented carbide layer increased to ∼ 2000 HV, which was about 1.5 times higher than that of the as-sprayed cemented carbide layer. Additionally, the cemented carbide layer was bonded to the SKD61 (Nominal composition: 0.35–0.42 mass% C, 0.8–1.2 mass% Si, 0.25–0.5 mass% Mn, 4.8–5.5 mass% Cr, 1.0–1.5 mass% Mo, 0.8–1.2 mass% V, balance Fe) substrate by diffusion of the metallic elements and the distortion of the coating–substrate interface producing a mechanical interlocking effect.
TL;DR: In this paper, a tool design with a smooth concave shoulder and a 12.7mm step-spiral pin was used for friction stir processing of NiAl bronze plates.
Abstract: The stir zone (SZ) temperature cycle was measured during the friction stir processing (FSP) of NiAl bronze plates. The FSP was conducted using a tool design with a smooth concave shoulder and a 12.7-mm step-spiral pin. Temperature sensing was accomplished using sheathed thermocouples embedded in the tool path within the plates, while simultaneous optical pyrometry measurements of surface temperatures were also obtained. Peak SZ temperatures were 990 °C to 1015 °C (0.90 to 0.97 TMelt) and were not affected by preheating to 400 °C, although the dwell time above 900 °C was increased by the preheating. Thermocouple data suggested little variation in peak temperature across the SZ, although thermocouples initially located on the advancing sides and at the centerlines of the tool traverses were displaced to the retreating sides, precluding direct assessment of the temperature variation across the SZ. Microstructure-based estimates of local peak SZ temperatures have been made on these and on other similarly processed materials. Altogether, the peak-temperature determinations from these different measurement techniques are in close agreement.
TL;DR: In this paper, the microstructures of aluminum samples, of three levels of purity, manipulated their grain sizes, making them finer, using friction stir processing, with the goal of high-strain-rate processing.
25 Nov 2010-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper, an IF steel was subjected to friction stir processing using a carbide-tungsten pin with the diameter of 16mm and the rotating speed of pin was 1600-rpm, whereas, the applied traverse speed was 31.5mm/min.
Abstract: An IF steel was subjected to friction stir processing using a carbide-tungsten pin with the diameter of 16 mm. The rotating speed of pin was 1600 rpm, whereas, the applied traverse speed was 31.5 mm/min. The specimens were water quenched immediately after the FSP. The microstructural evolutions were then characterized using atomic force microscopy (AFM), field emission scanning electron microscopy (FESEM), XRD and scanning electron microscopy (SEM) techniques. The results show that the FSP of IF steel resulted in the formation of a 30–35 μm thick surface layer with the nanograins of 50–125 nm. There was a continuous decrease in the hardness from the nanograin surface layer towards the center of specimen. There was almost a three-fold increase in the hardness, reaching to 310 Hv pertaining to the nanograin stirred zone compared to the 100 Hv related to the base material. The restoration mechanisms responsible for the formation of nanograins are then discussed.
TL;DR: In this article, the effects of FSP on the microstructure and mechanical properties of an investment cast Al-7Si-Mg alloy were assessed, showing that FSP eliminates porosity and significantly refines eutectic Si particles.
Abstract: Friction stir processing (FSP) is emerging as a promising tool for microstructural modification. The current study assesses the effects of FSP on the microstructure and mechanical properties of an investment cast Al-7Si-Mg alloy. FSP eliminates porosity and significantly refines eutectic Si particles. The extent of particle refinement varied with changes in processing conditions. A high tool rotation rate and a low-to-intermediate tool traverse speed generated a higher volume fraction of finer particles. Tensile ductility changed significantly as a result of FSP, whereas ultimate tensile strength improved only marginally. Yield strength was similar in both cast and FSP samples under various heat-treated conditions, with the highest value obtained after a T6 heat treatment. Furthermore, FSP caused significant grain refinement in the stir zone, subsequently transforming into very coarse grains as abnormal grain growth occurred during solution treatment at high temperature.
TL;DR: In this article, the texture evolution in the near surface layer during friction stir processing of AZ31 magnesium alloy was studied, and it was shown that texture evolution influenced the grain structure development.
Abstract: Microstructure and texture evolution in the near-surface layer during friction stir processing (FSP) of AZ31 magnesium alloy was studied. Material flow was found to be a very complex process consisting of several stages. The material in front of the friction stir tool was first deformed by the rotating shoulder. Then, approaching the tool, it experienced a secondary deformation caused by the rotating pin, and finally, behind the tool, it again underwent a tertiary deformation induced by the shoulder. The texture evolution was shown to dictate the grain structure development.