Grain refinement of aluminum alloys by friction stir processing

Most of the industrial applications based upon surface properties. Aluminum and its alloys are mostly used in the surface application industries due to their excellent mechanical and corrosive properties. However, it exhibits poor tribological properties. To enhance the mechanical and wear properties of the material grain refinement mechanism is to be incorporated. To improve the surface properties of the material the Friction stir Processing (FSP) Technique is mostly used nowadays. FSP plays an important role in modifying the surface in an efficient, environmentally friendly, and economical manner. This review article describes the current status of the FSP Technology in grain refinement of Aluminum alloys.

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Towards finding a novel constant between local and bulk strength of friction stir processed aluminum alloys

Proceedings of the Institution of Mechanical Engineers Part L Journal of Materials Design and Applications ◽

10.1177/14644207211025055 ◽

2021 ◽

pp. 146442072110250

Author(s):

MVNV Satyanarayana ◽

Adepu Kumar ◽

K Kranthi Kumar

Keyword(s):

Aluminum Alloys ◽

Grain Refinement ◽

Friction Stir Processing ◽

Linear Relation ◽

Alloy System ◽

Primary Objective ◽

Experimental Investigations ◽

Friction Stir ◽

Surface Composites ◽

Local Strength

Friction stir processing has gained remarkable success in producing ultrafine-grained structures and surface composites. In this context, the primary objective is to establish a linear relationship between local strength (i.e. hardness) and bulk mechanical strength (i.e. tensile strength) of friction stir processed aluminum alloys using experimental investigations on selected alloy system together with data reported in literature sources. Initially, authors generated a linear relation between hardness and strength of friction stir processed aluminum alloys under different cooling conditions. After friction stir processing, recrystallized fine grains were formed and better refinement was achieved in cooling-assisted friction stir processing. Irrespective of grain refinement, the strength and hardness of friction stir processed samples were found to be lower compared to the base metal due to the precipitation phenomenon during friction stir processing. At the same time, hardness and strength improved in cooling-assisted friction stir processing compared to natural-cooled friction stir processing due to better grain refinement going by the parameters of Hall–Petch equation. For friction stir processed samples, relevant constants were found using Hall–Petch equation. The experimental values of hardness and strength were well fitted with the formulated equations due to the formation of a homogeneous fine-grained structure. Also, two novel linear relations were successfully established between hardness and strength with proportionality constants of 1.9 and 2.7, respectively. On the other hand, it was also concluded that it is not possible to establish a linear relation between hardness and strength of surface composites due to structural inhomogeneity and agglomeration of reinforcement particles.

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Possibilities to Apply Friction Stir Processing FSP in Surface Engineering

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.890.56 ◽

2021 ◽

Vol 890 ◽

pp. 56-65

Author(s):

Cristian Ciucă ◽

Lia Nicoleta Boțilă ◽

Radu Cojocaru ◽

Ion Aurel Perianu

Keyword(s):

Aluminum Alloys ◽

Friction Stir Processing ◽

Surface Engineering ◽

Copper Alloys ◽

Welding Process ◽

Industrial Applications ◽

Process Conditions ◽

Cast Aluminum ◽

Friction Stir ◽

Cast Aluminum Alloys

The results obtained by ISIM Timisoara to the development of the friction stir welding process (FSW) have supported the extension of the researches on some derived processes, including friction stir processing (FSP). The experimental programs (the researches) were developed within complex research projects, aspects regarding the principle of the process, modalities and techniques of application, experiments for specific applications, being approached. The paper presents good results obtained by friction stir processing of cast aluminum alloys and copper alloys. The optimal process conditions, optimal characteristics of the processing tools were defined. The complex characterization of the processed areas was done, the advantages of the process applying being presented, especially for the cast aluminum alloys: EN AW 4047, EN AW 5083 and EN AW 7021. The characteristics of the processed areas are compared with those of the base materials. The results obtained are a solid basis for substantiating of some specific industrial applications, especially in the automotive, aeronautical / aerospace fields.

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

Materials Science and Engineering ◽

10.4018/978-1-5225-1798-6.ch051 ◽

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.

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