scholarly journals The Influences of Process Parameters on the Preparation of Closed-cell Aluminum foam by Friction Stir Processing

2021 ◽  
Author(s):  
Qiu Pang ◽  
Zhengjian Wu ◽  
Zhili Hu
Keyword(s):  
Base Metal ◽  
Process Parameters ◽  
Friction Stir Processing ◽  
Aluminum Matrix ◽  
Maximum Temperature ◽  
Welding Temperature ◽  
Rotating Speed ◽  
Friction Stir ◽  
Closed Cell ◽  
Al Foam

Abstract In the present investigation, the closed-cell Al foam was fabricated by friction stir processing (FSP) combined with heat treatment. The influences of process parameters on microstructures of closed-cell Al foam precursor were investigated by optical metallographic microscope and scanning electronic microscope (OM/SEM). Fluent CFD software was developed to simulate the temperature field and flow field in friction stir processing. The cupping test values were compared for base metal and different weld passes. The results show that the welding speeds have little effect on the mixing of powder in the stir zone because of the relatively small welding heat input. However, the pore size and pore morphology are highly sensitive to change in the rotating speeds. When the welding speed is 50mm/min and the rotating speed is 2000rpm, the powder ring is continuous and uniform due to sufficient plastic deformation and flow. When the foaming time is 110s, the expansion rate of the whole foam increases rapidly, and the diameter of the pore is uniform. Numerical simulation shows that the welding heat mainly comes from the shoulder of the stirring head and the welding temperature peak appears near the stirring pin. The maximum flow velocity appears at the outer edge of the shaft shoulder in which the aluminum matrix is softened preferentially. When the rotating speed increases to 2000r/min, the velocity of the outermost edge of the shaft shoulder increases by 59.96%, and the maximum temperature at the stirring pin reaches 491℃ which is consistent with the experimental results. The formability of the joint interface is improved. The cupping test values increase with the increase of deformation temperature. Especially the cupping test value of foamed preform is close to that of base metal at 450℃.

Microstructure and properties of Cf + TiB2/7075-modified layer by friction stir processing

2020 ◽  
Vol 10 (10) ◽  
pp. 1740-1745
Author(s):  
Shengrong Liu ◽  
Feng Xu ◽  
Hongfeng Wang ◽  
Xiaole Ge ◽  
Jiafei Pu
Keyword(s):  
Wear Resistance ◽  
Base Metal ◽  
Process Parameters ◽  
Friction Stir Processing ◽  
Friction And Wear ◽  
Base Material ◽  
Wear Test ◽  
Hardness Test ◽  
Friction Stir ◽  
Modified Layer

This study was aimed at preparing a modified layer by implanting Cf + TiB2 mixed particles into the 7075 aluminum alloy using the friction stir processing (FSP) technology. The microstructure, hardness, and wear resistance of the FSP-modified area with different process parameters were studied by microstructure analysis, hardness test, and friction and wear test. The results showed that the grains were refined and distributed evenly; the hardness was improved, especially in the central part of the region; and the friction coefficient was smaller in the FSP-modified region in comparison with the that of the base metal under different process parameters. Moreover, the wear form of the base material and the FSP-modified area was "furrow + adhesion" comprehensive wear form, in which the base metal was mainly adhesive wear and the FSP-modified area was mainly furrow wear. The grain refinement and hardness of the FSP-modified region obtained at a rotation speed of 1000 rpm and a forward speed of 10 mm/min were improved, and the wear resistance was the best.

scholarly journals Shoulder Related Temperature Thresholds in FSSW of Aluminium Alloys

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4375
Author(s):  
David G. Andrade ◽  
Sree Sabari ◽  
Carlos Leitão ◽  
Dulce M. Rodrigues
Keyword(s):  
Heat Generation ◽  
Process Parameters ◽  
Rotational Speed ◽  
Aluminium Alloys ◽  
Spot Welding ◽  
Base Material ◽  
Main Process ◽  
Welding Temperature ◽  
Friction Stir ◽  
Tool Diameter

Friction Stir Spot Welding (FSSW) is assumed as an environment-friendly technique, suitable for the spot welding of several materials. Nevertheless, it is consensual that the temperature control during the process is not feasible, since the exact heat generation mechanisms are still unknown. In current work, the heat generation in FSSW of aluminium alloys, was assessed by producing bead-on-plate spot welds using pinless tools. Coated and uncoated tools, with varied diameters and rotational speeds, were tested. Heat treatable (AA2017, AA6082 and AA7075) and non-heat treatable (AA5083) aluminium alloys were welded to assess any possible influence of the base material properties on heat generation. A parametric analysis enabled to establish a relationship between the process parameters and the heat generation. It was found that for rotational speeds higher than 600 rpm, the main process parameter governing the heat generation is the tool diameter. For each tool diameter, a threshold in the welding temperature was identified, which is independent of the rotational speed and of the aluminium alloy being welded. It is demonstrated that, for aluminium alloys, the temperature in FSSW may be controlled using a suitable combination of rotational speed and tool dimensions. The temperature evolution with process parameters was modelled and the model predictions were found to fit satisfactorily the experimental results.

scholarly journals Fabrication of AA7075 Hybrid Green Metal Matrix Composites by Friction Stir Processing Technique

2020 ◽  
Vol 44 (4) ◽  
pp. 295-300
Author(s):  
Sanjay Kumar ◽  
Ashish Kumar Srivastava ◽  
Rakesh Kumar Singh
Keyword(s):  
Mechanical Properties ◽  
Process Parameters ◽  
Friction Stir Processing ◽  
Research Work ◽  
Processing Technique ◽  
Matrix Composites ◽  
Avant Garde ◽  
Friction Stir ◽  
Surface Composites ◽  
Tool Tilt Angle

Friction stir processing is an avant-garde technique of producing new surface composite or changing the different properties of a material through intense, solid-state localized material plastic deformation. This change in properties depends upon the deformation formed by inserting a non-consumable revolving tool into the workpiece and travels laterally through the workpiece. This research work highlights the effect of process parameters on mechanical properties of fabricated surface composites by friction stir processing. By using various reinforcing materials like Ti, SiC, B4C, Al2O3 with waste elements like waste eggshells, rice husks, coconut shell and coir will be used to fabricate the green composites which are environmentally friendly and reduces the problem of decomposition. The parameter for this experiment is considered as the reinforcing materials, tool rotation speed and tool tilt angle. The SiC/Al2O3/Ti along with eggshell are selected asreinforcement materials. The main effect of the reinforcement is to improve mechanical properties, like hardness, impact strength and strength. The results revealed that the process parameters significantly affect the mechanical properties of friction stir processed surface composites.

Significance of Al2O3 addition in the aluminum 6063 metal foam formation through friction stir processing route – A comprehensive study

2021 ◽  
pp. 146442072110345
Author(s):  
Sharaf U Nisa ◽  
Sunil Pandey ◽  
PM Pandey
Keyword(s):  
Friction Stir Processing ◽  
Metal Foam ◽  
Aluminum Matrix ◽  
High Energy ◽  
Processing Route ◽  
Alumina Powder ◽  
Foam Formation ◽  
Porous Aluminum ◽  
Friction Stir ◽  
Blowing Agent

Closed-cell porous aluminum is expected to be a prominent material in near future because of its light weight, high specific modulus of elasticity, high energy absorption efficiency and high sound-insulating capacity in the automotive and aerospace industries. Recently, a new method of foaming has been developed in which a precursor is formed using friction stir processing. In the friction stir processing route, a precursor is fabricated by embedding a mixture of blowing agent powder and stabilization agent powder into aluminum alloy plates by the significant stirring action of friction stir processing. By applying the friction stir processing route precursor method, the cost-effective Al-foam formation along with high productivity can be accomplished. In this study, titanium hydride powder has been used as the blowing agent as it is reported to be most compatible with aluminum matrix. The effect of percentage of stabilization agent, i.e. alumina powder on porosity of aluminum foams formed using friction stir processing route is analyzed. The porous aluminum formed with three different percentages of alumina is observed and their porosity is calculated. Also, the compressive performance of the obtained samples is observed in order to examine the alumina powder addition on mechanical properties of the obtained metal foam. This study aims at analyzing the significance of addition of the alumina into the blowing agent while developing the metal foam through friction stir processing route.

Influence of Process Parameters on Microstructure of Friction Stir Processed Mg AZ31 Alloy

2017 ◽  
pp. 1293-1305
Author(s):  
G. Venkateswarlu ◽  
M.J. Davidson ◽  
G.R.N. Tagore ◽  
P. Sammaiah
Keyword(s):  
Plastic Deformation ◽  
Grain Refinement ◽  
Process Parameters ◽  
Tilt Angle ◽  
Friction Stir Processing ◽  
Rotational Speed ◽  
Traverse Speed ◽  
Homogeneous Microstructure ◽  
Friction Stir ◽  
Tool Tilt Angle

Friction stir processing (FSP) has been developed on the principles of friction stir welding (FSW) as an effective and efficien new method for grain refinement and microstructural modification, providing intense plastic deformation as well as higher strain rates than other conventional severe plastic deformation methods. FSP produces an equiaxed homogeneous microstructure consisting of fine grains, resulting in the enhancement of the properties of the material at room temperature. The objective of the present paper is to examine the influence of friction stir processing (FSP) parameters namely tool rotational speed (RS), tool traverse speed (TS) and tool tilt angle (TA) on the microstructures of friction stir processed AZ31B-O magnesium alloy. This investigation has focused on the microstructural changes occurred in the dynamically recrystallised nugget zone/ stir zone and the thermo mechanically affected zone during FSP. The results presented in this work indicate that all the three FSP process parameters have a significant effect on the resulting microstructure and also found that the rotational speed has greatly influenced the homogenization of the material. The grain refinement is higher at intermediate rotational speed (1150 rpm), traverse speed (32 mm / min and tilt angle (10). It is established that FSP can be a good grain refinement method for improving the properties of the material.

Fabrication and characterization of friction stir processed Al 6061 reinforced with TiB2-Al2O3

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ch. Mohana Rao ◽  
K. Mallikarjuna Rao
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Process Parameters ◽  
Friction Stir Processing ◽  
Practical Implication ◽  
Research Work ◽  
Influence Of Process Parameters ◽  
Volume Percentage ◽  
Content Type ◽  
Friction Stir

PurposeThe objective of the paper is to evaluate the fabrication process and to study the influence of process parameters of friction stir processing of 6061-TiB2-Al2O3 Aluminum alloy surface composite on microhardness tensile strength, and microstructure.Design/methodology/approachFriction stir processing method is used for attaining the desired mechanical properties, and selectively processed reinforcements to fabricate the samples. The Taguchi technique was used to optimize rotational speed, travel speed and volume percentage of reinforcement particles to enhance the mechanical properties of 6061-TiB2-Al2O3 Aluminum alloy composite.FindingsThe fabrication of surface composites through FSP allows new inventions in terms of material with enhanced surface layers without changing the base metal.Practical implicationsTo examine the behavior of the surface of the composites in the different zones, the practical implication consists of the use of different characterization techniques like optical microscopy and scanning microscopy for microstructural behavior and the measurement of hardness and tensile tests for mechanical behavior.Originality/valueThe research work consists of tool design and process parameters, which can affect the final product (microstructural changes), and the performance of the modified surface layer behavior was studied and presented.

Corrosion behavioral studies on AA7075 surface hybrid composites tailored through friction stir processing

2020 ◽  
Vol 67 (4) ◽  
pp. 345-355
Author(s):  
Suganeswaran Kandasamy ◽  
Parameshwaran Rathinasamy ◽  
Nithyavathy Nagarajan ◽  
Karthik Arumugam ◽  
Rajasekar Rathanasamy ◽  
...  
Keyword(s):  
Corrosion Rate ◽  
Friction Stir Processing ◽  
Hybrid Composites ◽  
Film Formation ◽  
Content Type ◽  
Rotating Speed ◽  
Friction Stir ◽  
Behavioral Studies ◽  
Base Matrix ◽  
Sem Micrograph

Purpose This paper aims to overcome the corrosion in AA7075 by incorporating the dual-reinforcements like Al2O3 and SiC through friction stir processing (FSP). In recent days, an automotive monocoque structure undergoes corrosion because of changes in environmental conditions. Design/methodology/approach Surface hybrid composites (SHCs) of AA7075 with different weight ratios of Al2O3 and SiC were fabricated at a rotating speed of 1000 rpm, traveling speed of 56 mm/min and tool tilt angle of 2º with two passes. Surface regions were observed using optical microscopy, and the potentiodynamic corrosion test was performed under a 3.5 per cent NaCl environment at room temperature. Then, the surface morphology analysis of corroded samples and their structural properties were also investigated through scanning electron microscopy (SEM), X-ray diffraction (XRD) and electron dispersive spectroscopy (EDS). Findings Through FSP, an improved interface between the reinforced particles and the AA7075 base matrix was observed because of the severe plastic deformation. Potentiodynamic polarization tests confirmed that the AA7075 matrix with a higher concentration of Al2O3 and a lower concentration of SiC (Al2O3 – 75 per cent and SiC – 25 per cent) possesses a lower corrosion rate than other specimens. This result is because of the combined effect of stable passive film formation and the resistance produced by hard SiC particles. In addition, the formation of a stronger interface between the reinforcements and the base matrix impedes the NaCl solution attack. The SEM micrograph depicts the film crystallinity variations with an increase in Al2O3 content. Debonding between the layers was observed on increasing the SiC content in the base matrix. XRD shows the peaks of reinforcing elements that influence the corrosion behavior. These observations suggest that the AA7075 reinforced with a higher concentration of Al2O3 and a lower concentration of SiC through FSP affords a suitable solution for automotive monocoque applications. Originality/value The corrosion rate has been identified for AA7075 SHCs with various concentrations of Al2O3 and SiC and has been compared with that of the base metal and the friction stir processed specimen without reinforcement.

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