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.

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.

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.

Microstructures and Mechanical Properties of AA6061-T4 Composites Containing SiC and B4C Particles Fabricated by Friction Stir Processing

2020 ◽  
Vol 12 (4) ◽  
pp. 531-537 ◽  
Author(s):  
Hyun-Joon Park ◽  
Byung-Wook Ahn ◽  
Jae-Ha Kim ◽  
Jong-Gun Lee ◽  
Seung-Boo Jung
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Friction Stir Processing ◽  
Vickers Hardness ◽  
Charpy Impact ◽  
Hardness Test ◽  
Charpy Impact Test ◽  
Ceramic Particles ◽  
Friction Stir ◽  
Microstructures And Mechanical Properties

AA6061-T4 composites containing SiC and B4C particles were fabricated by friction stir processing (FSP) with an SKD11 tool. The microstructures and mechanical properties of the composites were investigated with various test methods. With the inclusion of ceramic particles, refined grains in the stir zone (SZ) were observed using a scanning electron microscope (SEM) and tunneling electron microscope (TEM). Because the ceramic particles facilitated grain refinement in the SZ via the pinning effect, the SZ with the particles had a much smaller grain size than the SZ without the particles. Vickers hardness test, tensile test and Charpy impact test were conducted to evaluate the mechanical properties. Mechanical properties of the SZ with the ceramic particles were improved relative to those of the SZ without the particles. Vickers hardness (from 50 to 90 HV), tensile strength (from 117 to 253 MPa) and Charpy impact absorbed energy (from 4.2 to 5.6 J) of the SZ increased with the addition of ceramic particles.

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