Friction Stir Processing: An Operational Method to Improve Ductility in Pure Copper

2013 ◽  
Vol 818 ◽  
pp. 14-19 ◽  
Author(s):  
Vahid Rezazadeh ◽  
Ali Sharbatzadeh ◽  
Ali Hosseinzadeh ◽  
Amir Safari ◽  
Salar Salahi

mproving ductility in metals using friction stir processing (FSP) is a challenging effort and is made by means of a rotating tool inserted in a work piece providing heat transfer and plastic deformation. In this investigation, improving ductility during FSP was determined as a purpose and the microstructure and mechanical properties of nugget zone were investigated during friction stir processing (FSP) of pure copper. Ductility was measured using tensile elongations at a temperature of 20 °C. By varying the traverse speed from 40 to 100 mm/min at rotation speeds of 300 and 600 rpm, the ultrafine grain microstructure was achieved .Defects were observed in rotational speed of 300 rpm. By increasing traverse speed at constant rotational speed of 600 rpm grain size of the nugget zone decreased and ductility increased. Achievable ductility was limited by cavity formation due to lower heat input and deformation in samples with defects.

2013 ◽  
Vol 787 ◽  
pp. 256-261 ◽  
Author(s):  
Salar Salahi ◽  
Vahid Rezazadeh ◽  
Ali Sharbatzadeh ◽  
Atabak Iranizad ◽  
Hamed Bouzary

Recently friction stir processing (FSP) was developed as a generic implement for microstructural modification based on the principles of FSW using a rotating tool inserted in a monolithic work piece which provides frictional heating and mechanical mixing. In this paper, the microstructural evolution characteristics of nugget zone were investigated during friction stir processing (FSP) of pure copper. Pure copper plates were friction stir processed to the depth of 3.4 mm at different process conditions by varying the traverse speed from 30 to 120 mm/min at rotation speeds of 400 and 600 rpm..Defects were observed in rotational speed of 400 rpm. Grain size of NZ depended significantly on plastic deformation and heat input value. By increasing traverse speed at constant rotational speed of 600 rpm grain size of the nugget zone decreased and the hardness increased. Ultimate tensile strength increased with decrease in grain size. FSP was found as an effective method to develop fine-grained microstructure in copper plates.


2017 ◽  
pp. 1293-1305
Author(s):  
G. Venkateswarlu ◽  
M.J. Davidson ◽  
G.R.N. Tagore ◽  
P. Sammaiah

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.


2014 ◽  
Vol 592-594 ◽  
pp. 234-239 ◽  
Author(s):  
A. Thangarasu ◽  
N. Murugan ◽  
I. Dinaharan ◽  
S.J. Vijay

Friction stir processing (FSP) is as a novel modifying technique to synthesize surface composites. An attempt has been made to synthesis AA6082/TiC surface composite using FSP and to analyze the effect of tool rotational speed on microstructure and microhardness of the same. The tool rotational speed was varied from 800 rpm to 1600 rpm in steps of 400 rpm. The traverse speed, axial force, groove width and tool pin profile were kept constant. Scanning electron microscopy was employed to study the microstructure of the fabricated surface composites. The results indicated that the tool rotational speed significantly influenced the area of the surface composite and distribution of TiC particles. Higher rotational speed provided homogenous distribution of TiC particles while lower rotational speed caused poor distribution of TiC particles in the surface composite. The effect of the tool rotational speed on microhardness is also reported in this paper.


Author(s):  
A. Kumar ◽  
A. Devaraju ◽  
B. Kotiveerachari

In this investigation, the influence of tool rotational speed on wear and mechanical properties of Aluminum alloy based surface hybrid composites fabricated via Friction stir processing (FSP) was studied. The fabricated surface hybrid composites have been examined by optical microscope for dispersion of reinforcement particles. Microstructures of all the surface hybrid composites revealed that the reinforcement particles (SiC, Gr and Al2O3) are uniformly dispersed in the nugget zone. It is observed that the microhardness is decreased with increasing the rotational speed and exhibited higher microhardness value in Al-SiC/Al2O3 surface hybrid composite at a rotational speed of 900 rpm, due to presence and pining effect of hard SiC and Al2O3 particles. It is also observed that high wear resistance exhibited in the Al-SiC/Gr surface hybrid composites at a rotational speed of 900 rpm due to presence of SiC and Gr acted as load bearing elements and solid lubricant respectively. The observed wear and mechanical properties have been correlated with microstructures and worn morphology.


Author(s):  
G. Venkateswarlu ◽  
M.J. Davidson ◽  
G.R.N. Tagore ◽  
P. Sammaiah

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.


2016 ◽  
Vol 30 (2) ◽  
pp. 241-254 ◽  
Author(s):  
Jicheng Gao ◽  
Yifu Shen ◽  
Chao Li

The focus of this work was to study the effect of multiwalled carbon nanotubes (MWCNTs) on morphology, mechanical, and thermal properties of high-density polyethylene (HDPE) nanocomposites. MWCNTs/HDPE nanocomposites were prepared using submerged friction stir processing (SFSP) technique. The pristine MWCNTs without any pretreatment were blended with HDPE at a fixed traverse speed of 30 mm min−1 and various rotational speeds ranging from 1200 r min−1 to 2100 r min−1. The effect of rotational speed on MWCNTs dispersion in HDPE matrix was assessed using scanning electron microscopy. The experimental results showed the rotational speed affected the disperision of the MWCNTs. The mechanical properties of the composites were measured, and the results indicated that the tensile strength increased at first and then decreased with the increase of the rotation speed. The thermal properties of MWCNTs-filled HDPE nanocomposites were studied by differential scanning calorimetry, and the crystalline content of the prepared composites by the SFSP technology was increased. From the experimental research, it was found that the SFSP technique was a practical way to fabricate polymeric composites.


Author(s):  
Chao Shi ◽  
Chao Liu ◽  
Kaizhen Zhu

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.


2019 ◽  
Vol 8 (2) ◽  
pp. 6058-6061

In this study, the influence of friction stir processing process parameters (FSP), such as tool rotational speed, tool traverse speed, and the tool tilt angle on the mechanical properties of Sic reinforced surface magnesium rare earth ZE41 alloy composite was studied. The process was carried at tool rotational speeds of 710, 900, 1120, 1600, 1400 and 1800 rpm, tool traverse speeds of 16, 25, 40 and 63 mm/min and tool tilt angle of degree 1. Nano-particles of SiC (40 microns) were used as reinforcements to produce a composite surface. The grain refinement of the processed specimens was analyzed using scanning electron microscope. It is observed from the results that FSP process parameters influenced the surface composite area, SiC particles distribution and micro hardness of the composite. The outcomes indicated that the higher micro hardness was obtained at rotational speed of 1100 RPM, traverse speed 40mm/min and tilt angle 10 .


2015 ◽  
Vol 830-831 ◽  
pp. 467-471 ◽  
Author(s):  
P. Naresh ◽  
Adepu Kumar

In this investigation, the effect of nanoreinforcement particles such as Al2O3, tool rotational speed and traverse speed on microstructure and mechanical properties of Al/Al2O3surface nanocomposites fabricated by friction stir processing was studied. The surface nanocomposites were produced by varying volume percentage of nanoreinforcement, tool rotational speed and traverse speed to attain the best outcome. The fabricated composites were characterized through microstructural evaluation, microhardness measurements and energy dispersive spectroscopy analysis. Microstructural evaluation of the composites revealed that the composites were produced finer grain structure in this stir zone and it is evident for, a dynamic recrystallization was taken place. Higher hardness values were found at the stir zone of the entire composite because of the equiaxed and well dispersion of reinforced particles. The energy dispersive spectroscopy analysis revealed the presence of various elements at the stir zone. A defect free parameter setting for friction stir processing of Al/Al2O3was obtained at 1120 rpm and 16 mm/min.


2011 ◽  
Vol 312-315 ◽  
pp. 319-324 ◽  
Author(s):  
Mohsen Barmouz ◽  
M.K. Besharati Givi ◽  
Parviz Asadi

Friction stir processing (FSP) was applied to modify the microstructure of pure copper and Cu/SiC nanocomposite layers. Optical and scanning electron microscopy (SEM) was employed to investigate the microstructure on the modified surface. Also, the wear resistance and friction coefficient behavior of specimens were investigated. FSP homogenizes and refines the copper structure and creates a microstructure with nano-sized SiC particles (30 nm) distributed in the pure copper matrix. Also, it is found that the traversal speed of tool significantly influence the microstructure of developed zone in pure copper. Generally, higher tool traverse speed leads to a more homogeneous microstructure and SiC particles dispersion. This means that higher traverse speeds result in agglomeration of SiC particles which reduces the microhardness values.


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