Remanufacturing the AA5052 GTAW Welds Using Friction Stir Processing

Progress in sustainable manufacturing is a crucial element to minimise negative environmental impacts. The conventional fusion weld process used to join aluminium alloys resulted in coarse grain structure, inevitable defects, and severe joint softening. Friction stir processing (FSP) has the potential to modify the microstructure of materials in joint structure and improve the mechanical properties. In this investigation, the effect of friction stir post–processing was evaluated to study the microstructural characteristics and mechanical properties of GTAW (gas tungsten arc welding) welds in the aluminium 5052 alloy. During FSP, the grains’ dendritic microstructure was destroyed, and the dynamic recrystallisation resulted in a very fine and equiaxed grains structure in the fusion zone. The hardness of the friction-stir-processed welds significantly improved because of microstructure grain refinement. The processed joint demonstrated higher ultimate tensile and yield strength (~275 MPa and 221 MPa, respectively) and superior elongation (31.1%) compared to the unprocessed weld; at the same time, the mechanical strength (yield and ultimate tensile) is similar to that of the base metal.

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Microstructures and Properties of Biological Mg-Zn-Y-Nd Alloy by Friction Stir Processing

Materials Science Forum ◽

10.4028/www.scientific.net/msf.745-746.33 ◽

2013 ◽

Vol 745-746 ◽

pp. 33-38 ◽

Cited By ~ 1

Author(s):

Shi Jie Zhu ◽

Li Guo Wang ◽

Jin Jin ◽

Jing Wang ◽

Yu Feng Sun ◽

...

Keyword(s):

Mechanical Properties ◽

Friction Stir Processing ◽

Cast Alloy ◽

Corrosion Current ◽

Stir Zone ◽

Grain Structure ◽

Second Phase ◽

Uniform Corrosion ◽

Corrosion Properties ◽

Friction Stir

In order to improve the mechanical properties and processing performance of the Mg alloys, and to prevent magnesium alloy from non-uniform corrosion and too fast degradation in the degradation process, the biological medical Mg-Zn-Y-Nd alloy was modified by the friction stir processing (FSP) technique in this paper. The microstructural evolution and phase constitute of the stir zone of Mg-Zn-Y-Nd alloy were investigated, the microhardness and the corrosion properties of the alloy after FSP process was studied. The results showed that the FSP parameters had significant influence on the stir zone and thermo-mechanically affected zone. The stir zone experienced severe plastic deformation and complete dynamic recrystallization after FSP. The stir zone consists of fine equiaxed recystallized grains, and thermo-mechanically affected zone (TMAZ) has deformed grain structure. The second phase distributed along grain boundaries in as-cast state was broken during the FSP and transformed into fine, uniform and dispersed particles in the grains. After FSP, the size of grains was reduced from 50μm (as-cast alloy) to 1-2μm. However, the second phase constitution didnt change. The alloy obtained good comprehensive mechanical properties after FSP. The microhardness of alloy after FSP increased from 39HV (as-cast alloy) to 64HV(FSPed alloy). The results of electrochemical tests in simulated body fluid showed that the corrosion potential of FSP alloy increased and corrosion current density decreased, which confirmed the uniform corrosion of FSPed alloy.

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Improving the Microstructure and Mechanical Properties of a Cast Mg-9Al-1Zn Alloy Using Friction Stir Processing

Materials Science Forum ◽

10.4028/www.scientific.net/msf.838-839.214 ◽

2016 ◽

Vol 838-839 ◽

pp. 214-219 ◽

Cited By ~ 6

Author(s):

Wai Hoe Loke ◽

Raafat Ibrahim ◽

Sri Lathabai

Keyword(s):

Mechanical Properties ◽

Friction Stir Processing ◽

Intermetallic Phase ◽

Az91 Alloy ◽

Dendritic Microstructure ◽

Sand Cast ◽

Friction Stir ◽

Microchemical Analysis ◽

Microhardness Profile ◽

Shear Punch Testing

Friction stir processing (FSP) is a novel thermo-mechanical technique for modifying the microstructure of metals and alloys at targeted locations. In the present study, the microstructures and mechanical properties of friction stir processed Mg-9Al-1Zn (AZ91) alloy were evaluated. 4 mm thick sand cast AZ91 plates with a coarse dendritic microstructure and visible intermetallic phase were processed using single-pass FSP with different combinations of tool rotational and traverse speeds. Significant grain refinement (<10 μm), elimination of casting defects and the dissolution of intermetallic phase were observed at the stir zone (SZ) of all tested specimens. Microhardness tests showed increased microhardness along the SZ with a more uniform microhardness profile as compared to the regions outside the SZ. Mechanical properties evaluation using shear punch testing and subsequent microstructure analysis performed using scanning electron microscopy and microchemical analysis using Energy Dispersive Spectroscopy are discussed in this paper.

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Enhanced Mechanical Properties of Stainless Steel 316 L via Friction Stir Processing

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.297-301.215 ◽

2010 ◽

Vol 297-301 ◽

pp. 215-220 ◽

Cited By ~ 2

Author(s):

R. Salekrostam ◽

M.K. Besharati Givi

Keyword(s):

Mechanical Properties ◽

Stainless Steel ◽

Friction Stir Processing ◽

Composite Layer ◽

Grain Structure ◽

Sheet Metals ◽

Stainless Steel 316L ◽

Friction Stir ◽

State Process ◽

Stainless Steel 316

Friction stir processing (FSP) is a solid state process to modify microstructure and mechanical properties of sheet metals and as-cast materials. In this process stirring action of the tool causes the material to intense plastic deformation that yields a dynamical recrystalyzation. In this study the effect of FSP and process parameters on hardness, and microstructure of stainless steel 316L has been investigated. Also by using of FSP, a composite layer of 316L/SiC has been produced. Results show that FSP leads to a finer and homogenized grain structure, as well as increased hardness, strength, toughness, and elongation at failure of the material. The composites produced by FSP have a uniform distribution of SiC particles between the grains of the base metal.

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Mechanical properties and corrosion resistance of the fine grain structure of Al–Zn–Mg–Sc alloys fabricated by friction stir processing and post-heat treatment

Materials Science and Engineering A ◽

10.1016/j.msea.2020.139393 ◽

2020 ◽

Vol 785 ◽

pp. 139393

Author(s):

Y.F. Hou ◽

C.Y. Liu ◽

B. Zhang ◽

L.L. Wei ◽

H.T. Dai ◽

...

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Corrosion Resistance ◽

Friction Stir Processing ◽

Grain Structure ◽

Post Heat Treatment ◽

Friction Stir ◽

Fine Grain ◽

Mechanical Properties And Corrosion

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Microstructure Control and Mechanical Properties of Multipass Friction Stir Processed High Strength Aluminum Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.735.316 ◽

2012 ◽

Vol 735 ◽

pp. 316-321 ◽

Cited By ~ 1

Author(s):

Yutaka Matsuda ◽

Goroh Itoh ◽

Yoshinobu Motohashi

Keyword(s):

Mechanical Properties ◽

Aluminum Alloy ◽

Base Metal ◽

Friction Stir Processing ◽

Superplastic Deformation ◽

High Strength ◽

7075 Aluminum Alloy ◽

Friction Stir ◽

High Strength Aluminum Alloy ◽

Equiaxed Grains

Friction stir processing (FSP) causes fine-equiaxed microstructure[1]. In this study, microstructure and mechanical properties of a 7075 aluminum alloy subjected to multipass FSP, MP-FSP, are assessed. A new zone, PBZ, has been discovered between stir zones, SZs. The SZs are composed of fine-equiaxed grains, while PBZs are composed of two types of (fine-equiaxed and coarse-elongated) grains, both of which are still finer than those of base metal. Elongation at 773K of MP-FSPed specimen becomes larger than that of base metal, based on superplastic deformation due to the finer microstructure. Local elongation is smaller in PBZ than in SZ.

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