Multi-pass Friction Stir Processing Research Articles

Mechanical Properties and Microstructure Evolution Of AA6082/Sic Nanocomposite Processed by Multi-Pass FSP

Mechanical Properties and Microstructure Evolution Of AA6082/Sic Nanocomposite Processed by Multi-Pass FSP

The Influence of Multipass Friction Stir Processing on Formation of Microstructure and Mechanical Properties of Ti6Al4V Alloy

The Influence of Multipass Friction Stir Processing on Formation of Microstructure and Mechanical Properties of Ti6Al4V Alloy

In Situ Intermetallics-Reinforced Composite Prepared Using Multi-Pass Friction Stir Processing of Copper Powder on a Ti6Al4V Alloy.

Multi-pass friction stir processing (FSP) was used to obtain a titanium alloy/copper hybrid composite layer by intermixing copper powder with a Ti6Al4V alloy. A macrostructurally inhomogeneous stir zone was obtained with both its top and middle parts composed of fine dynamically recrystallized α- and β-Ti grains, as well as coarse intermetallic compounds (IMCs) of Ti2Cu and TiCu2, respectively. Some β grains experienced β → α decomposition with the formation of acicular α-Ti microstructures either inside the former β-Ti grains or at their grain boundaries. Both types of β → α decomposition were especially clearly manifested in the vicinity of the Ti2Cu grains, i.e., in the copper-lean regions. The middle part of the stir zone additionally contained large dislocation-free β-Ti grains that resulted from static recrystallization. Spinodal decomposition, as well as solid-state amorphization of copper-rich β-Ti grains, were discovered. The FSPed stir zone possessed hardness that was enhanced by 25% as compared to that of the base metal, as well as higher strength, ductility, and wear resistance than those obtained using four-pass FSPed Ti6Al4V.

Correction to: Effect of Multipass FSP on Si-Rich TIG Welded Joint of Dissimilar Aluminum Alloys AA8011-H14 and AA5083-H321: EBSD and Microstructural Evolutions

Correction to: Effect of Multipass FSP on Si-Rich TIG Welded Joint of Dissimilar Aluminum Alloys AA8011-H14 and AA5083-H321: EBSD and Microstructural Evolutions

Effect of multi-pass friction stir processing on the microstructure evolution and corrosion behavior of ZrO2/AZ31 magnesium matrix composite

Most of magnesium matrix composites processed by traditional technique have poor anti-corrosion and biological performance, because of uneven microstructure, especially for nonuniform distribution of reinforced particles. Friction stir processing (FSP) can be used for preparing magnesium matrix composites with refine grains and uniform distribution of reinforced particles. In this paper, multi-pass FSP is employed to fabricate the ZrO2 particles reinforced AZ31 magnesium composites. The results showed that the microstructure of the composites become more homogeneous with the increase of FSP pass. The grain size is refined from 10 μm of basal metal (BM) to 8.2 μm of two-pass FSP (FSP-2P) and 4.5 μm of four-pass FSP (FSP-4P), respectively. The ultimate tensile strength, yield strength and elongation of BM is 283 MPa, 137 MPa and 15.5%. The mechanical properties are improved with the increase of FSP pass. The ultimate tensile strength, yield strength and elongation of FSP-4P is 328 MPa, 160 MPa, and 11.5%, respectively. Moreover, the corrosion resistance is arranged in the following order: FSP-2P < BM < FSP-4P. The cell activity of FSP-4P is higher than that of FSP-2P sample, which is similar to BM.

Influence of multi-pass friction stir processing on the formation of microstructure and mechanical properties of Ti6Al4V alloy

Friction stir processing (FSP) is an advanced technology for altering the surface microstructure of metals and alloys to improve mechanical and performance properties. Previous research on titanium alloy processing showed that varying the FSP process parameters (such as rotational speed, movement speed and tool contact force) significantly affects the Ti–6Al–4V microstructure evolution and mechanical properties. However, the effect of multipass FSP on the Ti–6Al–4V alloy was not studied. Therefore, this paper studies the effect of four-pass FSP of the Ti–6Al–4V titanium alloy on the microstructure evolution, mechanical properties and wear resistance of this alloy. Microstructure analysis showed that the stirring zone forms heterogeneous microstructure with dynamically recrystallized equiaxed α grains, β grains and β areas with α phase of needle and laminar type, which is associated with the stirring zone temperature gradient during FSP. It was found that an increase in the number of FSP passes up to 3 times improves the ultimate tensile strength (up to 1173 MPa) and wear resistance (by 33 %). The improved ultimate tensile strength of samples after 3 FSP passes is caused by grain size reduction in the stirring zone by 88 % compared to the initial Ti–6Al–4V alloy. It was shown that after 4 FSP passes the grain size increases and the ultimate tensile strength decreases to 686 MPa in the stirring zone, which is associated with large defects formed along the contour of metal flows. At the same time the Ti–6Al–4V wear resistance after 4 FSP passes increases by 39 % compared to the raw material.

Effect of Multipass FSP on Si-rich TIG Welded Joint of Dissimilar Aluminum Alloys AA8011-H14 and AA5083-H321: EBSD and Microstructural Evolutions

Effect of Multipass FSP on Si-rich TIG Welded Joint of Dissimilar Aluminum Alloys AA8011-H14 and AA5083-H321: EBSD and Microstructural Evolutions

CNT-reinforced Al-xZr (x = 0.25, 0.5 and 1 wt.%) surface composites fabricated by friction stir processing: microstructural, mechanical and wear characterisation

ABSTRACT In the present study, carbon nanotubes (CNTs) were dispersed in the cast Al-xZr (x = 0.25, 0.5 and 1 wt.%) alloys by multi-pass friction stir processing (FSP) to fabricate novel Al-xZr/CNT surface composites. The effect of Al3Zr precipitate and CNTs either separately or in aggregate form on the microstructure, mechanical properties and wear behaviour were investigated. Due to the formation of Al3Zr particles, the addition of Zr modified the microstructure and improved the mechanical and wear properties. As the Zr content increased from 0.25 to 1 wt.%, the grain size reduced from ∼220 µm to ∼106 µm, the tensile strength increased from ∼83 MPa to ∼98 MPa, and the friction coefficient decreased from 0.768 to 0.64. FSP refined the grain structure and caused fragmentation and redistribution of the Al3Zr, improving mechanical and wear properties. The FSPed Al-%1Zr alloy exhibited a grain size of 7.8 µm, tensile strength of 164 MPa and friction coefficient of 0.482. Further improvement in the mechanical and wear properties were obtained by incorporating the CNTs into Al-xZr alloy. In particular, the Al-1%Zr/CNT composite with the grain size of ∼3 µm showed the most significant tensile strength of 215 MPa, the lowest friction coefficient of 0.209 and the highest wear resistance. The improvement in mechanical properties of the composites was mainly attributed to the grain refinement and the load transfer model.

Fabrication of surface composites on different aluminium alloys via friction stir process - A review report

ABSTRACT Friction stir processing (FSP) is used to enhancing the hardness, tensile strength, corrosion and wear resistance of the substrate by changing the microstructure and through reinforcing the surface with hard-particles. In this paper, the available literatures have been carefully scrutinised and systematically categorised into FSP process and its resulting effects on the different grades of aluminium-based metal matrix composites (AMMCs). The effect of various reinforcements on AMMCs is also discussed. The objective of this paper is to review the various FSPed AMMCs fabricate at different operating conditions under various FSP parameters and summarise their effects on the microstructure and final properties of surface composites. Improvement in mechanical properties, corrosion resistance and wear resistance were observed. Fine grains of 100 nm to 400 nm in size were obtained in AA7075-T6 matrix after multi-pass FSP with rapid cooling. In AA7075/9 wt% TiB2 SCs, the grain size reduces from 335 µm (cast AA7075) to 6.3 µm, UTS increased to ~237%, hardness increased to ~246% and wear rate reduced to ~47% as compared to cast AA7075. This review paper will be helpful to new researchers working in the field of FSP, as it comprises significant knowledge related to AMMCs through FSP.

Influence of tool travel direction on microhardness and tribological properties of AA2014/SiC-CNT hybrid surface composites produced by multi-pass friction stir processing

Friction Stir Processing (FSP) is a novel technique that is widely used to produce surface composites (SC). In FSP, the surface properties of the material can be altered as per the requirement and generally depends upon the type of reinforcement. In hybrid surface composites, two or more reinforcement particles (RP) are added to get the combined enhanced properties of the reinforcement and thus increase the overall properties of the surface composites. In this paper, FSP was employed on AA2014 aluminum alloy to produce the surface composite by using SiC-CNT hybrid reinforcement. Since the number of FSP pass plays an important role while deciding the properties of the produced surface composites, a total of 3 FSP passes were used in this paper. The direction of the FSP passes was changed after each pass. The produced surface composite was then measured for its microhardness, optical microscopy, wear resistance, and coefficient of friction (COF). It was observed that the alteration in FSP pass results in better uniformity of the microhardness and produces a uniform distribution of reinforcement in the surface composites.

Fabrication of Al-Zr -Mg-Ni matrix composite with TiC reinforcement by multi-pass recursive friction stir processing and its characterization

A titanium carbide (TiC)-reinforced Al-Zr-Mg-Ni matrix was utilized for conjunction with multi-pass friction stir processing to create the composite. Reverse engineering and geometric reconstruction techniques were employed to produce a spherical channel at a prearranged depth from the area using wire-EDM and filled with reinforcement elements to prevent the spread of reinforcement particles during fabrication. Multiple recursive passes during friction stir processing were studied to determine the effects on particle distribution and crystallographic texture, as well as surface roughness and mechanical properties. The results showed that increasing the number of passes significantly improved particle distribution and reduced defects such as particle agglomeration and voids. After six passes, the grain size was condensed to 2.40 nm while the dislocation density increased due to the uniform distribution of TiC particles. Grain refinement led to a significant increase in the texture index, which resulted in a surface roughness of 153.593 nm. After six passes, the composite's hardness and tensile strength had increased due to the even distribution of TiC particles and various strengthening mechanisms.

Effects of multipass friction stir processing and Mg addition on the microstructure and tensile properties of Al 1050 alloys

Effects of multipass friction stir processing and Mg addition on the microstructure and tensile properties of Al 1050 alloys

Effect of multi-pass friction stir processing on microstructure and mechanical properties of cast A216 alloy

Effect of multi-pass friction stir processing on microstructure and mechanical properties of cast A216 alloy

Optimization of process parameters on the mechanical properties of AA6061/Al2O3 nanocomposites fabricated by multi-pass friction stir processing

In the present investigation, the empirical correlation was successfully developed to predict the input and output responses of the multi-pass friction stir processing (FSP)/Al2O3 nanoparticles at a 95% confidence interval (C.I). The base metal AA6061 was characterized by nanoparticles Al2O3 within the structure of the coarse dendrite. These coarse and dendrites clusters were successfully broken by multi-pass FSP (MPFSP), refined the matrix grains and produced a homogenous microstructure in the stir zone (SZ). The developed model reveals that the nanoparticles Al2O3 and FSP passes were the dominating parameters to enhance the mechanical properties of the MPFSP/Al2O3. The ultimate tensile strength (UTS) and hardness were increased with increases in nanoparticles Al2O3 and the FSP passes. The optimized value of UTS, % strain and microhardness was observed as 220.07 MPa, 13.36%, and 98.44 HV, respectively, while the optimized value of nanoparticles Al2O3 and number of FSP passes were 9.65% and 1.72, respectively.

Optimizing the mechanical properties of Al-4.5Cu-xSi alloys through multi-pass friction stir processing and post-process aging

Optimizing the mechanical properties of Al-4.5Cu-xSi alloys through multi-pass friction stir processing and post-process aging

Effect of multi-pass friction stir processing and SiC nanoparticles on microstructure and mechanical properties of AA6082-T6

In this work, aluminum matrix composite (AMC) was successfully fabricated by multi-pass friction stir processing (MPFSP) with nanoparticles SiC. A constant rotational tool speed of 1350, feed rate of 65 mm/min, tilt angle of 2° was used to enhance the microstructure and mechanical properties of multi-pass FSP/SiC of AA6082-T6. It can be observed that Nanoparticles SiC were fragmented totally and uniformly distributed in fifth pass FSP. Agglomeration of SiC decreases with increases in the number of passes. The ultimate tensile strength (UTS) of base metal AA6082 exhibited 215.54 MPa, and % strain of 24.91. After implementing multi-pass FSP with nanoparticles of SiC on the AA6082, the UTS was enhanced simultaneously as the FSP pass increases. The UTS of 1st pass, 2nd pass, 3rd pass, 4th pass, and 5th pass was observed as 223.61 MPa, 238.37 MPa, 255.63 MPa, 281.79 MPa and 296.86 MPa, respectively caused by strain-free fine grains during dynamic recrystallization (DRX) mechanism. In contrast, Vickers's hardness value along the centerline (stir zone) was observed as 89, 101, 119, 125, 133 HV with 1st pass, 2nd pass, 3rd pass, 4th pass, and 5th pass respectively.

Investigation of microstructure, crystallographic texture, and mechanical behavior of magnesium-based nanocomposite fabricated via multi-pass FSP for biomedical applications

In this work, the microstructure, crystallographic texture, hardness, and tensile behavior of AZ91/HA bio-nano composite manufactured by multi-pass friction stir processing (FSP) were investigated. With increasing the number of FSP passes, the average size of grains is reduced. The processed AZ91 and AZ91/HA nanocomposite after the third pass had the lowest grain size (4.5 and 2.6 μm, respectively). Also, the average grain size of composites was smaller than that of monolithic samples at the same pass number. The results showed that particle distribution in the AZ91/HA nanocomposite is significantly affected by the number of passes. The increment of the pass number led to a more uniform dispersion of HA nanoparticles in the matrix due to more plastic flow of materials. With increasing the pass number to three, the accumulated strain increased to 0.726 (monolithic) and 0.623 (composite) due to repeating mechanical stirring. There was a texture transition ({101‾1} to {0002}) via performing only one pass of FSP. Suppression of grain rotation by HA nanoparticles maintained the intensity of {101‾1} texture as a corrosion-resistant orientation after the third pass. With increasing the pass number of FSP, the hardness and strength of samples increased due to the grain size reduction and the more uniform dispersion of HA powder. The composite sample after the third pass exhibited the highest hardness of 117.0 HV and ultimate tensile strength of 306.6 MPa. The failure mode of processed samples was ductile. There were smaller dimples on the fracture surface of the composite samples due to their lower grain size and also the presence of HA nanoparticles. Considering the obtained results, the nanocomposite after the third pass can be a good load-bearing implant for biomedical applications.

Effect of graphite exfoliation through multipass friction stir processing on microstructure and mechanical properties of aluminium 7075‐silicon carbide‐graphite composites

AbstractIn this study, friction stir processing techniques has been utilized to fabricate graphite‐reinforced aluminium matrix composite. Silicon carbide will be mixed together with graphite flakes as reinforcement with the composition of hybrid ratio 60 : 40. The manipulated variable of this project is the number of passes used during friction stir processing (1, 2 and 3 passes). Three different number of passes are used to investigate its effect onto the reinforcement dispersion inside the aluminium metal matrix composites. Microstructural analysis has shown that with increasing number of passes, the distribution of reinforcement particles becomes more uniform and homogeneous. Nanoreinforcement particle dispersions are observed and analysed. Result shows that the size of agglomerations across the composite surface decreases as the number of passes increases. Further observation and analysis of on the particles has confirmed that graphite flakes have been successfully shear exfoliated into layers to cover more surface area. The overall mechanical properties have also observed significant increase with increasing number of passes. Sample with highest number of pass (3 pass run) managed to achieve maximum tensile strength and elongation percentage of 304.04 MPa and 2.54 %, respectively, which is the highest value among all the samples tested.

Mechanical properties and structure formation of aluminum-silicon alloys after friction stir processing

This study presents the results of experimental work on obtaining and investigating samples obtained by multipass friction stir processing of the Al-12 %Si and Al-9 %Si aluminum-silicon alloys. The results indicate a beneficial effect of friction stir processing on the strength properties of both alloys. The number of tool passes along the processing line has no effect on the mechanical properties and particle size of silicon in the aluminum matrix. The greatest influence on the mechanical properties is exerted by the first pass with the tool. The yield strength of the processed Al-9 %Si alloy increases by more than a factor of 1.5, whereas for the Al-12 %Si alloy there is no increase in yield strength. The tensile strength of the Al-12 %Si alloy increases by 17 %, while that of the Al-9 %Si alloy increases by 29 %. The most significant is the increase in relative elongation to failure, namely 77 % for Al-12 %Si and 113 % for Al-9 %Si.

Interface repairing for AA5083/T2 copper explosive composite plate by friction stir processing

Multi-pass friction stir processing (M-FSP) was performed to repair the interface defects of AA5083/T2 copper explosive composite plates. The interface morphology and its bonding mechanism were explored. The results show that higher rotation speed and lower transverse speed produce more heat generated during FSP. The defect-free and good mechanical properties of the AA5083/T2 copper composite plate can be obtained under the condition of the rotation speed of 1200 r/min, the transverse speed of 30 mm/min and the overlap of 2/24. Moreover, M-FSP changes the interface bonding mechanism from metallurgical bonding to vortex connection, improving the bonding strength of composite plate, which can guarantee the repairing quality of composite plates.