Mechanical Properties Of Friction Stir Research Articles

Influence of tool velocity ratio on force-torque and mechanical properties of friction stir welded 2050-T84 Al-Li alloy plates

Abstract Aluminium-lithium (Al-Li) alloy is the most prominent alloy used in the aerospace industry's internal structure and wings due to its improved physical and mechanical properties. The present study introduces a novel investigation into the joining of Al-Li alloy 2050-T84 using friction stir welding (FSW) at different tool velocity ratios (TVR) of 0.6, 0.8, and 1, respectively (i.e., the amalgamation of various process parameters like tool rotational speed (TRS of 600, 1000, and 1400 rpm and traverse speed of 60, 120, and 240 mm/min) and constant tool tilt angle (1.50). A threaded taper tool was used for joining the Al-Li alloy 2050-T84. This work aims to ascertain the effects of varying tool velocity ratios (TVR; rotational speed/traverse speed) on macrostructure, grain size distribution in the nugget zone, and mechanical strength of the welded specimens. The experimental results reveal that increasing the tool velocity ratio increases the grain size and decreases the welded specimen's ultimate strength and hardness values. Higher tensile strength (403.2 MPa), micro-hardness values (122.15 HV0.1), and joint efficiency (75.49) of welded specimens are achieved at low TVR (0.6), and ductile failure is observed in all welded samples. Additionally, it is noticed that the stirred zone size increased with increasing the velocity ratio.

Microstructure evolution and local mechanical properties of friction stir additively manufactured (FSAM) AA5083/AA6061/AA7075 gradient composite.

The current study is focused on the successful fabrication and characterization of microstructure and properties gradient composite made of 3 mm thick sheets of AA5083-O, AA6061-T6, and AA7075-T6 alloys using friction stir additive manufacturing (FSAM) technique. Two combinations of four layered FSAM builds (6756 and 7567) were fabricated successfully without any major defects at the optimized process parameters of 850 rpm (tool rotational speed) and 55 mm/min (tool transverse speed). The material mixing, interfacial bonding features, microstructure evolution, and mechanical performance within the stir zones (SZ) were thoroughly examined using advanced characterization techniques. Electron backscatter diffraction (EBSD) analysis confirmed a gradient microstructure along the build depth in both FSAM builds, with average grain sizes decreasing from 52 μm (AA5083), 46 μm (AA6061), and 40 μm (AA7075) in base metals to ∼ 4 to 7 μm within the SZ. The remarkable grain refinement within the SZ was mainly attributed to the dominant presence of the continuous dynamic recrystallization (CDRX) mechanism. Texture analysis corresponding to pole figures (PFs) and orientation distribution function (ODF) plots reveals the crystallographic texture evolution along the build depth. The prevalent existence of B/ and C textures throughout all regions of the FSAM builds affirms the presence of ample shear strain during the FSAM procedure. Through thickness miniature tensile and microhardness tests depict the gradient in mechanical performance for both the FSAM builds along the build depth. Microhardness gradients in the range from 80 HV0.1 to 145 HV0.1 were observed along the build depth. The axial sample in the build direction shows appreciable strength (265 MPa and 224 MPa) and uniform elongation (28% and 24 %) for 6756 and 7567 FSAM build, respectively. Furthermore, remarkable strain hardening behaviour corresponding to hardening capacity (Hc) and hardening exponent (n) was noticed for both the axial build samples compared to AA6061-T6 and AA7075-T6 base metals. These findings underscore the potential of FSAM in fabricating functionally gradient composite materials tailored to specific functional requirements.

Effect of Welding Conditions on Weld Zone Temperature and Mechanical Properties of Friction Stir Welded AZ61 Magnesium Alloy Sheet

Effect of Welding Conditions on Weld Zone Temperature and Mechanical Properties of Friction Stir Welded AZ61 Magnesium Alloy Sheet

Microstructural Characteristics and Mechanical Properties of Friction Stir Welded 2219 Aluminum Alloy Plate After Spinning and Heat Treatment

Microstructural Characteristics and Mechanical Properties of Friction Stir Welded 2219 Aluminum Alloy Plate After Spinning and Heat Treatment

Microstructure and mechanical properties of friction stir welded AZ31 magnesium alloy reinforced with ZrB2

Abstract Metal matrix composites (MMC) have advantages over polymer matrix composites such as high stiffness and strength, high-temperature resistance, better abrasion resistance, creep resistance, resistance to degradation by fluids, dimensional stability, and non-flammability. Metal matrix composites are used for various applications in the automotive, aerospace and sporting goods industries. The primary objectives of the current research work encompass the fabrication of Metal Matrix Composites (MMCs) AZ31 with 0.5%, 1.0% and 1.5% zirconium boride (ZrB2) nano-powder by the stir casting process, followed by welding through Friction Stir Welding (FSW). The metallographic analysis was carried out on the weldments of all cases. The macroscopic and microscopic analysis confirmed the defect-free weld joint. Tensile and hardness tests were conducted to study the mechanical properties of the materials. The tensile strength and the percentage of elongation increased with the percentage of ZrB2. But, after 1.0% addition of nano particles the strength decreased. The same pattern had been observed in both base and welded samples. The defect-free welding joints were fabricated with an efficiency of 79.1%, 79.7% and 77.7% for the materials with 0.5%, 1.0% and 1.5% nano powder, respectively. EIS and PDP tests were conducted in 3.5% NaCl to study the corrosion behaviour of base and welded materials. The corrosion tests on the base MMC samples showed that the corrosion resistance increased after the addition of ZrB2 nanoparticles. In addition, the corrosion resistance of all the welded samples improved compared with their respective base materials.

Effect on microstructure and mechanical properties of friction stir welded 5A06 aluminum alloy joints by deep cryogenic treatment

In order to improve the comprehensive mechanical properties of the welded joints of the 5A06 aluminum alloy, friction stir welded (FSW) joints were subjected to deep cryogenic treatment (DCT). The microstructure and mechanical properties were characterised using metallographic microscopy, x-ray diffractometer (XRD), energy spectrometer, microhardness tests, and tensile tests. The experimental results show that DCT refines the structure significantly due to the large temperature difference. This refinement results from an increase in Mg atoms within the α-Al solid solution through the precipitation of Al atoms, forming the Al3Mg2 phase. This enhancement in plasticity is achieved through dispersion distribution. Moreover, as the treatment time of DCT increases, the mechanical properties of the welded joint also improve significantly. The microhardness of the welding joint peaked at DCT3h, rising from 78.8 HV at DCT0h to 87.2 HV at DCT3h. Meanwhile, the tensile strength of the joint reached its maximum at DCT12h, rising from 358.7 MPa at DC0h to 385.3 MPa at DCT12h, representing a 7.4% increase. These experimental results underscore the significant impact of DCT on improving the welded joints.

Effect of material position and tool offset on the microstructure and mechanical properties of friction stir welded AA7075/AZ31B with ultrasonic assistance

The primary focus of this study is to analyze how changes in material position and tool offset affect the microstructure and mechanical properties of dissimilar alloys (AA7075/AZ31B) joints. The study specifically examines these effects in normal and ultrasonic-assisted friction stir welded (UVaFSW) aluminum and magnesium-based joints. The experiment showed that the sound weld was achieved only when the AA7075 plate was placed on the advancing side (AS). The metallographic analysis showed that the use of ultrasonic vibration increased the flow of material in the nugget zone (NZ) and improved the length of interpenetration at the interface. Moreover, the intermetallic compound (IMC) layer thickness decreased throughout the interface during UVaFSW, improving joint strength. The maximum ultimate tensile strength was obtained at 1 mm tool-off condition for UVaFSW, i.e., 112.40 ± 7.24 MPa. Ultrasonic vibrations reduced the IMC thickness by up to 78 % at the middle of the joint interface. The fracture surface showed the ductile fracture mode in the case of UVaFSW compared to the FSW process. The current study establishes the framework for optimizing and controlling the welding process of dissimilar AA7075/AZ31B alloys, which possess considerable potential for use in the aviation industry.

Microstructure Evolution and Mechanical Properties of Friction Stir Welded Al–Cu–Li Alloy

Microstructure Evolution and Mechanical Properties of Friction Stir Welded Al–Cu–Li Alloy

Analyzing the Influence of Microstructure on the Mechanical Properties of TIG Welded Joints processed by Friction Stir considering the sampling Orientation

The contribution of the microstructural arrangement to the mechanical properties of friction stir processed Tungsten Inert Gas (TIG) welded joints is reported in this work. The TIG-welded joints were subjected to a single pass of Friction Stir Processing (FSP). The friction stir processed joint was sampled transversally and longitudinally, and different tests were conducted and studied comparatively. The microstructural analysis showed refined grains with varying degrees. The mean grain size for the transversally sampled specimen was found to be 11.48 µm, while the longitudinally sampled specimen had varying mean grain size from 7.32 µm to 15.09 µm. The varying mean grain size of the longitudinally sampled specimen is caused by the staggered arrangement of the microstructure. The tensile properties and the microhardness of the transversally sampled specimen were lower than those of the longitudinally sampled specimen. The ultimate tensile strength of the transversally sampled specimen was found to be 87.88 MPa which is lower than that of the longitudinally sampled specimen (133.83 MPa). The microhardness of the longitudinally sampled specimen fluctuated between 30 HV and 80 HV while the transversally sampled specimen had a maximum microhardness of approximately 57 HV.

Reverse effects of pre-deformation and traverse speed on the mechanical properties of friction stir processed pure copper

In the present work, the effects of pre-strain and traverse speed on the microstructural evolution and tensile behavior of friction stir processed (FSPed) pure copper were investigated. In the samples without pre-deformation (0% samples), with the increment of the traverse speed from 100 mm min−1 to 200 mm min−1, the grain size decreased from 5.2 to 2.5 μm due to heat input domination. In the 60% pre-rolled samples (60% samples), interestingly, with an increase in the traverse speed (from 100 mm min−1 to 200 mm min−1), the average grain size increased from 2.4 to 6.8 μm owing to the domination of deformation degree. With the increment of speed from 100 mm min−1 to 200 mm min−1 in the 0% samples, the YS and UTS increased from 158.6 and 244.6 MPa to 190.7 and 253.9 MPa, respectively, due to decrement in the mean grain size. In addition, the increment of speed from 100 mm min−1 to 200 mm min−1 in the 60% samples reduced the YS and UTS from 177.9 and 261.7 MPa to 138.9 and 234.8 MPa, respectively, due to the increase in the mean grain size. In the 0% FSPed copper, by increasing the speed, the depth and size of dimples reduced, while, in the 60% FSPed samples, when the traverse speed increased, the dimples became larger.

Effect of Preheating Temperature on Microstructure and Mechanical Properties of Friction Stir Welded DMR249A HSLA Steel Joints

Effect of Preheating Temperature on Microstructure and Mechanical Properties of Friction Stir Welded DMR249A HSLA Steel Joints

Correlation of microstructure, texture, and mechanical properties of friction stir welded Joints of AA7075-T6 plates using a flat tool pin profile

This study investigates the influence of square and hexagon tool pin profiles on the butt joint of AA7075-T6 plates through friction stir welding. In contrast to the AA7075-T6 base metal with a grain size of 32.736 μm, both square (4.43 μm) and hexagon (5.79 μm) pin profiles led to a significant reduction in grain size within the stir zone (SZ) of the weld cross-section. The SZ region exhibited a gradient in recrystallization and a notable fraction of high angle grain boundaries, attributed to continuous dynamic recrystallization influenced by variations in temperature and strain rate. Pole figure analysis revealed predominant shear texture elements (B/ B‾ and C) with minor A1*/A2* and A/ A‾, indicating elevated strains within the SZ. Orientation distribution function (ODF) analysis identified recrystallization texture elements such as Goss {110} <001>, cube {001} <101>, and P {011} <112>, along with shear texture components F {111} <112> and rotating cube (H) {001} <110>. Tensile and nanoindentation analyses demonstrated that the weld joint using a square-shaped pin profile exhibited higher strength, elongation, and elastic modulus compared to other weld joints. These findings suggest that the square tool pin geometry enhances material flow and grain refinement during welding, thereby improving the mechanical properties of the joint.

Effect of different tool pin geometries on force, torque, microstructure and mechanical properties of friction stir welded acrylonitrile butadiene styrene and polycarbonate joints

Effect of different tool pin geometries on force, torque, microstructure and mechanical properties of friction stir welded acrylonitrile butadiene styrene and polycarbonate joints

Influence of pin profiles on temperature distribution, microstructure evolution and mechanical properties of friction stir welded AA6061

The friction stir welded (FSWed) butt-joints of 6061 aluminium alloy were fabricated by various pin geometries including cylindrical thread, tapered thread, triflate tapered thread and cylindrical non-thread. The attention was put on the role of the pin geometries in temperature distribution, microstructure evolution and mechanical properties of the joints. The history of changing welding temperature is validated through both experimental work and numerical simulation. The results showed that the highest welding temperature was obtained about 480 °C at triflate tapered thread pin in both experiment and numerical simulation. In all cases, the tensile strength was reached approximately 200 MPa with the joint efficiency of 80% in comparison with base metal. The fracture location of the joints was found in the heat affected zone, where the lowest value of hardness was obtained. The stress of root bend was lower than that of face bend. Crack-free on the welding surface of face bend indicated that the joints are ductile. However, the specific influence of pin geometries on the microstructure evolution and mechanical properties of the joints is insignificant in this work.

AN INTEGRATED APPROACH OF GRA COUPLED WITH PRINCIPAL COMPONENT ANALYSIS FOR FRICTION STIR WELDED AM20 MAGNESIUM ALLOY

Magnesium alloys possess highly desirable properties and become increasingly popular in various practical applications due to their lightweight nature as a replacement for aluminum alloys. The purpose of this study is to optimize the process parameter to get the better mechanical properties of friction stir welded AM20 magnesium alloy using Taguchi Grey relational analysis (GRA) Coupled with Principal Component Analysis (PCA). The considered process parameters are plunging depth (PD), tool rotation speed (RPM), and welding speed (WS), shoulder diameter (SD), and. The experiments were carried out by using Taguchi's L18 factorial design of experiment. The processes parameters were optimized and ranked the parameters based on the W-GRG. The responses are ultimate tensile strength (UTS), yield strength (YS), percentage of elongation (% E), compressive stress (CS), bending angle, average hardness at the nugget zone (NZ), thermo mechanical affected zone (TMAZ) and heat affected zone (HAZ). Case-1 is preferable when high values of quality parameters are desired, while Case-2 is more suitable when some parameters needs to be low values. The optimal combination of parameters in case-1 is PD1, RPM3, WS3, and SD1, while the optimal combination of parameters in case-2 is PD1, RPM1, WS2, SD1. In both cases, the most influence response in is UTS, while the maximum influence of factor is SD. We suggest further research to be able to use confirmatory experiments so that we can find out how well the new setup is suggested.

Effect of backing plate on microstructure and properties of friction stir welded 2195-O alloy

The effect of two different backing plate (BP) conditions on the microstructure and resulting mechanical properties of friction stir welded Al-Cu-Li alloy (2195-O) was investigated. This study shows that Copper-BP with lower welding temperature and higher cooling rate, forms finer grains in the nugget, resulting in higher yield strength. The steel-BP weld with higher peak temperature and lower cooling rate results in larger grain size in the nugget and greater solid solution strengthening. While the weld with the steel-BP had a marginally smaller yield strength, it displayed much greater work hardening rate along with better ageing response.

Influence of secondary welding on microstructure and mechanical properties of friction stir welded joints of AA6061 and AZ31B alloys

Butt joints made of 6061-T6 Al and AZ31B Mg dissimilar materials were fabricated using friction stir welding (FSW). Three welding techniques were used in the experimental process: method 1-Mg on the advancing side (AS), method 2-(Al on the AS), and method 3-(Mg was placed on the AS for the first welding experiment, and then the plate was rotated horizontally by 180° so that Al was placed on the AS for the second welding). Focus on the comparative analysis of the second welding and primary welding on the microstructure and mechanical properties of the joint. The results show that the joints with the secondary welding method have the characteristics of onion rings in the stirred zone (SZ), where there is a serious mixture of Al and Mg, and the degree of mechanical bonding is significantly increased. At the same time, the enhanced mechanical effect of secondary welding on the weld led to a change in the microhardness of the SZ. In the tensile tests, the strength of the secondary welded joint was increased to 120 MPa compared to the primary welded joint strength of 89 and 95 MPa due to the increase in the degree of mechanical bonding of the secondary welded joints and the increase in the level of mixing of plastic materials in the SZ. In addition, the type of fracture of the joint in all three welding methods is a brittle fracture.

Effect of process parameters on friction stir welding of aluminium alloy AA6082–T6 with an interlayer using response surface methodology

In the present study, the effects of variation of process parameters on the mechanical properties of friction stir welded A6082–T6 aluminium alloy joints with Zinc (Zn) interlayer are experimentally investigated. Four process parameters, viz. rotational speed, welding speed, interlayer thickness and tool pin diameter are selected to fabricate the Friction Stir Welding (FSW) joints. After filling the Zn particles into the gap maintained between the plates, FSW is performed using different process parameters. Thereafter, tensile and impact strength tests are performed to evaluate the performance of the joints. It is analyzed that the tensile and impact strength of the joints vary from 121 to 197 MPa and 6 to 17 J, respectively. Subsequently, mathematical models are developed using Response Surface Methodology (RSM) to predict the effect of FSW process parameters on the tensile and impact strength of joints. Analysis of Variance (ANOVA) is used to check the level and degree of direct effect of process variables on the tensile and impact strength of the joints. It is observed from the results that tool rotational speed is the most influential process parameter, which enhances the mechanical properties of FSW joints, whereas an increase in welding speed reduces the mechanical properties of the joints.

Microstructure evolution and mechanical properties of friction stir welded Fe50Mn30Co10Cr10 high-entropy alloy

Metastable Fe50Mn30Co10Cr10 HEA has a significant strength-ductility synergistic effect and a wide application prospect in nuclear power. The present work reports the microstructure evolution and tensile behavior of friction stir-welded joints for Fe50Mn30Co10Cr10 high entropy alloy (HEA) at various rotational speeds. Defect-free welds of Fe50Mn30Co10Cr10 alloy were obtained by a W-Re alloy welding tool. Significant grain refinement occurs in the nugget zone, where the most of HCP phases in the base metal transformed into FCC phase. Additionally, strain-induced Σ3 mechanical twins are generated in the FCC austenite grains. The microstructure of thermo-mechanically affected zone exhibited multiple deformation mechanisms, including stacking faults, martensite lath, martensite variants, and reverse transformation. The microhardness of the joint primarily depends on the grain size of the FCC phase and the fraction of twins and HCP phase. In the nugget zone of the joint welded at 300 rpm, a high microhardness zone ranging from 266.7 to 310 HV was detected. While the reverse transformation and fresh twinning in the joint at 600 rpm contribute to the enhancement of tensile properties, the increase in grain size and ε martensitic fraction have resulted in a noteworthy reduction in ultimate tensile strength (UTS) and elongation (EL). Conversely, the joint of 300 rpm exhibited optimum UTS and EL owing to the grain refining after FSW and the transformation induced plasticity (TRIP) effect. These insights confirm that FSW is an ideal approach for achieving superior joint performance in dual-phase HEAs.

Influence of process parameters on microstructure and mechanical properties of friction stir welded P91 industry grade steel pipes

Influence of process parameters on microstructure and mechanical properties of friction stir welded P91 industry grade steel pipes