The Mechanical Properties of Al-30Si Alloy by Friction Stir Processing

2011 ◽  
Vol 189-193 ◽  
pp. 3601-3604 ◽  
Author(s):  
Ye Hua Jiang ◽  
De Hong Lu ◽  
Ming Zhou ◽  
Shao Sheng Wei ◽  
Rong Zhou
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Friction Stir Processing ◽  
Tensile Behavior ◽  
Stir Zone ◽  
Hypereutectic Alloy ◽  
Friction Stir ◽  
Size And Morphology ◽  
Silicon Particles ◽  
Improvement Ratio

Friction stir processing (FSP) was applied to modify the surface of a hypereutectic alloy Al-30wt.%Si, the influence of FSP passes on the size and morphology of Si particles, the mechanical properties of the materials in the stir zone was investigated. In the nugget by FSP, the silicon particles were intensely refined to several micrometers and spheroidized, and the refinement and spheroidization degree increased with FSP passes. The tensile behavior of the alloy by FSP has typically plastic feature. With FSP passes increasing, the tensile strength and the elongation increased gradually, and the improvement ratio of the elongation is more obvious. The improvement is attributed to the spheroidization and refinement of silicon particles by FSP.

Stir zone material flow patterns during friction stir welding of heavy gauge AA5056 workpieces and stability of its mechanical properties

2021 ◽  
Vol 23 (4) ◽  
pp. 140-154
Author(s):  
Tatiana Kalashnikova ◽  
◽  
Vladimir Beloborodov ◽  
Kseniya Osipovich ◽  
Andrey Vorontsov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Friction Stir Welding ◽  
Elevated Temperatures ◽  
Thin Sheet ◽  
Stir Zone ◽  
Clear Correlation ◽  
Material Structure ◽  
Friction Stir ◽  
Significant Difference

Introduction. Friction stir welding and processing are almost identical processes of severe plastic deformation at elevated temperatures. These technologies differ mainly in the purpose of its use: the formation of a hardened surface layer or producing a welded joint. However, it is known that both during welding and during processing of heavy gauge workpieces temperature gradients occur. As a result, the conditions of adhesive interaction, material plastic flow, and the formation of the stir zone change as compared to thin-sheet workpieces with fundamentally different heat dissipation rates. In this connection, the purpose of the work is to determine the regularities of the structure formation and stability of the mechanical properties in different directions in the material of 35-mm-thick aluminum-magnesium alloy samples produced by friction stir welding/processing. Research Methodology. The technique and modes of friction stir welding and processing of AA5056 alloy workpieces with a thickness of 35 mm are described. Data on the equipment used for mechanical tests and structural research are given. Results and discussion. The data obtained show the excess mechanical properties of the processing zone material over the base metal ones in all studied directions. Material structure heterogeneities after friction stir welding/processing of heavy gauge workpieces have no determining effect on the stir zone properties. At the same time, there is no clear correlation between the tensile strength values and the load application direction, nor is there any significant difference in mechanical properties depending on the location of the samples inside the stir zone. The average ultimate tensile strength values in the vertical, transverse, and longitudinal directions are 302, 295 and 303 MPa, respectively, with the yield strength values of 155, 153 and 152 MPa, and the relative elongation of 27.2, 27.5, 28.7 %.

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

2013 ◽  
Vol 745-746 ◽  
pp. 33-38 ◽  
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.

scholarly journals Effect of Multiple Passes on Microstructural and Mechanical Properties of Surface Composite Al 2024/SiC Produced by Friction Stir Processing

2020 ◽  
Vol 44 (6) ◽  
pp. 421-426
Author(s):  
Ashish Kumar Srivastava ◽  
Nagendra Kumar Maurya ◽  
Manish Maurya ◽  
Shashi Prakash Dwivedi ◽  
Ambuj Saxena
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Friction Stir Processing ◽  
Hardness Test ◽  
Mechanical Tests ◽  
Matrix Composites ◽  
Application Range ◽  
Friction Stir ◽  
Morphological Aspects ◽  
Processed Sample

The application range in defense, aerospace and automotive sectors have enabled aluminium metal matrix composites to emerge in different technological fields due to enhanced micro structural and mechanical characteristics. In the present study, friction stir processing is used to fabricate Al2024/SiC composite with one, two and three passes of the cylindrical tool. Optical microscopy and scanning electronic microscope (SEM) were used to validate the processed sample and to justify the morphological aspects. Energy dispersive spectroscopy (EDS) analysis has also performed to confirm the presence of SiC particles in the composite. It also includes the analysis of mechanical properties such as tensile strength, Rockwell hardness test and nanoindentation to characterize the prepared samples. Improvement in tensile strength with a maximum of 443 MPa, the hardness of 121 HRB and nanoindentation of the specimen was depicted through the mechanical tests.

Investigations on microstructural and mechanical properties of friction stir welded AA 2024-T351

2020 ◽  
Vol 62 (8) ◽  
pp. 793-802
Author(s):  
Şefika Kasman ◽  
Sertan Ozan
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Welded Joints ◽  
Rotational Speed ◽  
Stir Zone ◽  
Tool Rotational Speed ◽  
Friction Stir ◽  
Aa 2024

Abstract In the present study, AA 2024-T351 plates with a thickness of 6 mm were joined using the friction stir welding technique with three different tool rotational speeds and two different pin profiles. Microstructural features and mechanical properties of welded joints were investigated. The grains in recrystallized regions along the stir zone were observed to be almost with invariable sizes. The grain size was revealed to increase with the increase in tool rotational speed. The average grain size was observed to dramatically increase from 2.3 μm to 5.6 μm for welded joints produced with pentagonal shaped pin. All the welded joints were observed to contain defects; the presence of defects exhibited a negative effect on the tensile properties of the welded joint. Most of the defects were observed to localize at the root region of joints. The joint, welded with the tool rotational speed of 250 rpm using pentagonal shaped pin, exhibited ultimate tensile strength with a value of 365 MPa. The ultimate tensile strength of welded joints was found to be higher with the decrease in the tool rotational speed. The welding efficiency of joints was compared with the ultimate tensile strength of base metal; notably, welding efficiency values between 46 % and 80 % were achieved. Microstructural characterizations revealed that Al2Cu (θ phase), Al2CuMg (S phase), and AlCuFeMnSi, Al7Cu2Fe intermetallic particles were dispersed in the stir zone.

Microstructure and Cryogenic Mechanical Properties of AA5083 Joints Prepared by Friction Stir Welding

2014 ◽  
Vol 788 ◽  
pp. 243-248 ◽  
Author(s):  
Bao Kang Gu ◽  
Da Tong Zhang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Tensile Testing ◽  
Base Material ◽  
Tensile Behavior ◽  
Planar Slip ◽  
Friction Stir ◽  
5083 Aluminum Alloy ◽  
Cryogenic Mechanical Properties

In this study, 5083 aluminum alloy plates with a thickness of 3mm are friction stir welded and the microstructure and mechanical properties of the joints were characterized. In particular, tensile behavior of the joints is examined at 77K. It is found that defect-free joints can be obtained under a tool rotational rate of 800rpm and a welding speed of 60mm/min. The friction stirring welds exhibit finer microstructure and higher hardness than that of the base material due to the grain refinement. The ultimate tensile strength (UTS) and elongation of the joints measured at 298K are 316MPa and 21.3%, which are nearly equal to those of the base material. With the tensile test temperature decreasing to 77K, UTS and elongation of both the base material and joints increase. Comparing with tensile testing at 298K, dimples on the fracture surface of the samples tested at 77K are more uniform in distribution. The improvement of the mechanical properties of specimens at low temperature is related to the inactivation of planar slip and the strengthening of strain hardening.

Wear and mechanical properties of surface hybrid metal matrix composites on Al–Si aluminum alloys fabricated by friction stir processing

2017 ◽  
Vol 233 (5) ◽  
pp. 790-799 ◽  
Author(s):  
Mostafa Akbari ◽  
Mohammad Hasan Shojaeefard ◽  
Parviz Asadi ◽  
Abolfazl Khalkhali
Keyword(s):  
Mechanical Properties ◽  
Mass Loss ◽  
Friction Stir Processing ◽  
Hybrid Composites ◽  
Relative Content ◽  
Stir Zone ◽  
Cast Aluminum Alloy ◽  
Cast Aluminum ◽  
Wear Properties ◽  
Friction Stir

Aluminum-base surface hybrid composites have been fabricated by mixtures of SiO2 and Al2O3 particles on an Al–Si cast aluminum alloy using friction stir processing with the aim of achieving higher wear properties in the Al piston alloy via surface hybrid composites fabrication. The distribution of particles in the stir zone was evaluated via scanning electron microscope. Microstructures of the composites revealed that the reinforcing particles were uniformly distributed in the stir zone. Furthermore, the mechanical properties of each composite were determined using hardness tests indicating that increase in the relative content of SiO2 resulting in a decrease in the average hardness of the stir zone. Additionally, the wear resistance of the surface hybrid composites was investigated under normal load, sliding speed, and distances of 20 N, 1 m/s, and 4000 m, respectively. It was found that the wear mass loss of the 20% SiO2–80% Al2O3 hybrid composites (which was about 4.2 mg) was improved when compared with that of the A356 base alloy (nearly 19 mg). Moreover, by increasing the relative content of SiO2 particles from 0% to 100% in the hybrid composites, the friction coefficient of the composites rose from 0.55 to 0.73. It can be concluded by adding Al2O3 and SiO2 particles in the Al matrix, wear mass loss can be decreased by about five times compared with that of the base metal, in which the Al2O3 particle increases the hardness and SiO2 particles acts as lubricating agent, and the combination of these leads to better wear properties. The best combination of the hybrid particles in order to achieve the best wear properties for the hybrid composites is 20% Al2O3 and 80% SiO2.

Friction Stir Processing (FSP) of Cast Metals: Microstructure – Property Relationships in NiAl Bronze and AA5083

2010 ◽  
Vol 638-642 ◽  
pp. 35-40
Author(s):  
Terry R. McNelley ◽  
Srinivasan Swaminathan ◽  
E. Sarath Menon ◽  
J.Q. Su
Keyword(s):  
Mechanical Properties ◽  
Ambient Temperature ◽  
Friction Stir Processing ◽  
Elevated Temperatures ◽  
Stir Zone ◽  
Friction Stir ◽  
Grain Structures ◽  
Microstructures And Mechanical Properties ◽  
Step Over ◽  
Equiaxed Grain

Parameters for multi-pass FSP include the pattern of tool traverse and step-over distance between successive passes. Multi-pass FSP was conducted on as-cast NiAl bronze and as-cast AA5083 in order to modify stir zone (SZ) microstructures and mechanical properties. Highly refined and homogeneous SZ microstructures may be produced by FSP. Refined and equiaxed grain structures reflect recrystallization during FSP; mechanisms leading to homogenization by redistribution of microstructure constituents remain to be determined. Refined microstructures exhibit enhanced ambient-temperature properties and superplasticity at elevated temperatures.

scholarly journals Effect of friction stir processing on microstructures and mechanical properties of TIG cladding layer on AA7075

2021 ◽  
Author(s):  
Chao Shi ◽  
Chao Liu ◽  
Kaizhen Zhu
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Friction Stir Processing ◽  
Rotational Speed ◽  
Traverse Speed ◽  
Stir Zone ◽  
Elemental Distribution ◽  
Friction Stir ◽  
Cladding Layer ◽  
Microstructures And Mechanical Properties

Abstract AA7075 is a precipitation strengthened Al-Zn-Mg-Cu alloy which has been widely used. As a common way to repair AA7075 components, tungsten inert gas (TIG) cladding generates coarse grains and defects. In addition, the use of other types of filler wires could lead to insufficient rigidity and strength of the cladding layer. In the present work, friction stir processing (FSP) has been applied to the TIG cladding layer on AA7075 to study the effect of process parameters on microstructures and mechanical properties. The macro/micro structural characteristics, elemental distribution, microhardness distribution and tensile properties have been investigated. The macroscopic defects in TIG cladding layer are eliminated and the size of grains is decreases to around 6 μm by FSP. FSP reduces the compositional difference between the stir zone and the base material. Higher rotational speed promotes the grain refinement while the lower traverse speed benefits the microstructural uniformity. FSP on the TIG weld bead brings improvement in tensile properties and hardness. All the fractures for TIG+FSP samples occur at thermo-mechanically affected zone of the advancing side. The tensile strength of the stir zone increases from 424.2 to 442.8 MPa with the increase in rotational speed and traverse speed.

Trade-off among mechanical properties and energy consumption in multi-pass friction stir processing of Al7075 alloy employing neural network–based genetic optimization

2016 ◽  
Vol 231 (1) ◽  
pp. 129-139 ◽  
Author(s):  
G Hussain ◽  
M Ranjbar ◽  
S Hassanzadeh
Keyword(s):  
Neural Network ◽  
Mechanical Properties ◽  
Tensile Strength ◽  
Friction Stir Processing ◽  
Electrical Energy ◽  
Processing Technique ◽  
Genetic Optimization ◽  
Trade Off ◽  
Friction Stir ◽  
Artificial Neural

Friction stir processing is a novel material processing technique. In this study, neural network–based genetic optimization is applied to optimize the process performance in terms of post-friction stir processing mechanical properties of Al7075 alloy and the energy cost. At first, the experimental data regarding the properties (i.e. elongation, tensile strength and hardness) and the consumed electrical energy are obtained by conducting tests varying two process parameters, namely, feed rate and spindle speed. Then, a numerical model making use of empirical data and artificial neural networks is developed, and multiobjective multivariable genetic optimization is applied to find a trade-off among the performance measures of friction stir processing. For this purpose, the properties like elongation, tensile strength and hardness are maximized and the cost of consumed electrical energy is minimized. Finally, the optimization results are verified by conducting experiments. It is concluded that artificial neural network together with genetic algorithm can be successfully employed to optimize the performance of friction stir processing.

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