Influence Of Tool Rotational Speed Research Articles

Influence of tool rotational speed on the microstructure and mechanical behavior of friction stir processed AA 7050 aluminum alloy

Influence of tool rotational speed on the microstructure and mechanical behavior of friction stir processed AA 7050 aluminum alloy

Investigations on surface properties of friction stir welded dissimilar AA2024-T3 and 304 stainless steel joints

The present study investigated the influence of tool rotational speed on dissimilar joints between AA2024-T3 and SS304 metals using friction stir welding (FSW). Optimal results were achieved at 560 rpm tool rotation, 25 mm/min traverse speed, and 1 mm tool pin offset. This rotation rate facilitated proper heat input, inducing plastic deformation and material flow, resulting in an ultrafine grain structure in the stir zone (SZ). 3D profilometry showed variable surface roughness affected by process parameters. Potentiodynamic tests demonstrated improved corrosion resistance in FSWed samples compared to the base material. Vickers hardness testing revealed increased hardness in the SZ due to grain refinement. Wear behavior evaluation highlighted the significant influence of tool rotation on enhancing wear resistance in welded specimens.

Friction stir processing of AZ31 alloy to improve the mechanical, biodegradation, and in vitro biocompatible characteristics

The aim of the study was to improve the mechanical, biodegradation and in vitro biocompatible characteristics of as received rolled AZ31 (Mg-1%Zn-3%Al) alloy by develop the surface composite of Mg-Titania. The surface composite was developed by friction stir processing (FSP) and it’s used for prosthetic applications. The influence of tool rotation speed and number of FSP passes on grain structure, grain refinement, tensile strength, hardness, in vitro degradation rate and in vitro biocompatibility were explored. The obtained results support the capability of FSP in terms of mechanical strengthening, refinement of grain structure, dispersion of reinforcement (i.e. TiO2) and controlled degradation rate. Grain structure at stir zone, advancing side and retreating side were investigated. The large grains in the alloy were reduced to a fine equiaxial grains of average dimension of ≈ 3 μm by 3rd pass of FSP. The process was performed under two different tool rotation speed, i.e. 1550 and 2260 RPM. The addition of second phase in the matrix significantly improve the grain refinement. The results obtained from tensile test revealed the improvement in the percentage elongation without compromising the strength. The micro hardness of specimens of different parametric combination were evaluated and found ≈ 30–50% improvement in the micro hardness. The degradation rate by immersion test in simulated body fluid (SBF) for 3, 6 and 10 days were performed and found a significant reduction in degradation rate. The MTT assay for the biocompatibility performed by indirect method, the results validate the non-toxic behavior of processed specimen.

Influence of tool rotational speed on mechanical and corrosion behaviour of friction stir processed AZ31/Al2O3 nanocomposite

Nano-sized reinforcements improved the mechanical characteristics efficiently by promoting more implicit particle hardening mechanisms compared to micron-sized reinforcements. Nano-sized particles lessen the critical particle solidification velocity for swamp and thus offers better dispersal. In the present investigation, the friction stir processing (FSP) is utilized to produce AZ31/Al2O3 nanocomposites at various tool rotation speeds (i.e., 900, 1200, and 1500 rpm) with an optimized 1.5% volume alumina (Al2O3) reinforcement ratio. The mechanical and corrosion behavior of AZ31/Al2O3-developed nanocomposites was investigated and compared with that of the AZ31 base alloy. The AZ31 alloy experienced a comprehensive dynamic recrystallization during FSP, causing substantial grain refinement. Grain-size strengthening is the primary factor contributed to the enhancement in the strength of the fabricated nanocomposite. Tensile strength and yield strength values were lower than those for the base metal matrix, although an upward trend in both values has been observed with an increase in tool rotation speed. An 19.72% increase in hardness along with superior corrosion resistance was achieved compared to the base alloy at a tool rotational speed of 1500 rpm. The corrosion currents (Jcorr) of all samples dropped with increase in the rotational speed, in contrast to the corrosion potentials (Ecorr), which increased. The values of Jcorr of AZ31/Al2O3 were 42.3%, 56.8%, and 65.5% lower than those of AZ31 alloy at the chosen rotating speeds of 900, 1200, and 1500 rpm, respectively. The corrosion behavior of friction stir processed nanocomposites have been addressed in this manuscript which has not been given sufficient attention in the existing literature. Further, this work offers an effective choice for the quality assurance of the FSP process of AZ31/Al2O3 nanocomposites. The obtained results are relevant to the development of lightweight automobile and aerospace structures and components.

The Effect of Tool Rotation Speed on the Formation of Eutectic Structure during Friction Stir Welding of Aluminum to Magnesium

Friction stir welding (FSW) is a solid-state welding process capable of joining a wide range of light metals. However, liquation and solidification may occur during joining of dissimilar metals which leads to eutectic formation. This article aims to discover the influence of tool rotation speed on the formation of eutectic structure during friction stir welding of aluminum to magnesium. To do so, friction stir welding was performed at 600 and 950 rpm to join pure aluminum and ECO-AZ91 magnesium alloy in a lap configuration. In order to investigate the influence of the welding speed, the welding speeds of 23.5 and 37.5 mm/min were also chosen. Scanning electron microscopy (SEM) was used to study the microstructure of the joints. A shear-tensile test was used to evaluate the joints’ strengths. The fracture surfaces were also studied by SEM. The results revealed that changing the rotation speed directly affects the eutectic formation, whereas the welding speed had no influence. A lower rotation speed resulted in a thin, continuous intermetallic layer, whereas a higher speed led to the formation of a massive Mg-Al12Mg17 eutectic microstructure. The formation of eutectic, as an indicative of liquation, may affect the material flow during the process due to decreasing the friction coefficient between the tool and material. The macrostructure analyses showed that the phase evolution as well as the mechanism of material flow are highly affected by liquation.

The influence of tool rotational speed on microstructure and mechanical performance of dissimilar FSLW

FSLW is a novel solid-sate joining process in aircraft assembly technology that has offered superior welding quality to the joining of aluminum alloy. Concerning the success of FSLW light metal alloys coupled with lower operating costs due to improved energy efficiency and virtual lack of a consumable has emphasized the need to examine AA 2024-T4 and AA 7075-T6 based on different tool rotational speeds (RSs). This research examined the three important determinants of FSLW: cross-section morphology, microstructure behavior, and mechanical performance (lap shear failure load and fracture location) to realize the quality and reasonable experiment of the welding technique. The cross-section of the lap joint is investigated in this experiment; it is evident that the maximum temperature is found in the stir zone, and the shape looks like a bowl type. Further, it is found that tool RS does not have an influence on the effective sheet thickness, but it influences the effective lap width. With the increased RS, the effective lap width increased first and then decreased. Concerning grain size analysis, the bigger grain size was observed in the heat-affected zone, and the smaller grain size was observed in the thermomechanical-affected zone. According to the mechanical performance analysis, the lap shear failure load increased and then reduced with increased RS.

Microstructure, mechanical and electrochemical studies of dissimilar friction stir welded aluminium alloys

In the present investigation, the influence of tool rotational speed (900, 1100, 1300, and 1500 rpm) on microstructure, mechanical characteristics, and corrosion behavior of friction stir welding (FSW) of dissimilar Al5083–6061 alloys was studied. Optical and scanning electron microscopes were used to study the microstructural features. The grain size measured at the stir zone (SZ) decreased considerably in contrast with the base materials (BM) but increased with tool rotational speed. The mixing degrees of two materials at the SZ are enhanced by increasing rotational speeds. The mechanical properties, such as hardness and tensile properties, were studied using Vicker’s hardness tester and universal testing machine. The hardness of the weld joints is inferior to that of the base metal, and uniform hardness distribution and the highest average hardness in SZ were obtained at 1100 rpm. The higher strength and elongation of 202 MPa and 5.2%, respectively, were achieved at 1100 rpm, with joint efficiency of 65%, due to optimum heat input, and the lowest tensile strength and elongation of 156 MPa and 3.2%, respectively, were obtained at 1300 rpm with a joint efficiency of 50% due to excess heat input. It is curious to note that an increase in tensile elongation accompanies the enhancement of weld strength. The fracture occurred at the retreating side of the heat-affected zone as it is the weakest zone in the FSWed joint. Different corrosion tests, such as immersion, open circuit potential, and Tafel polarization tests, were carried out using an electrochemical workstation. The corrosion findings showed that the corrosion resistance of the samples increased after the welding, and the highest corrosion resistance was obtained at 1100 rpm.

The influence of tool rotation speed on the low-cycle fatigue behavior of AA2519-T62 friction stir welded butt joints

The subject of this study were the friction stir welded butt joints of the 5 mm thick AA2519-T62 alloy obtained with four various values of tool rotation speed: 200, 400, 600 and 800 rpm, and the constant welding velocity of 100 mm/min. The examination involved macro and microstructure observations, microhardness, tensile, and fatigue testing. An increase in the stir zone size and microhardness has been reported together with increasing tool rotation speed. The weld obtained with the lowest value of tool rotation speed (200 rpm) is characterized by a significant reduction of microhardness in the SZ, which makes it very susceptible to plastic deformation. In terms of tensile properties, there is a tendency of increasing welds’ yield and tensile strength together with increasing applied tool rotation speed. The tensile failures occur in the LHZ, which is located, depending on tool rotation speed, at the SZ (200 rpm), at the HAZ/TMAZ interface (400 rpm) or at the SZ/TMAZ interface (600 and 800 rpm). For AA2519-T62 and its FSW joints, the cyclic strain hardening is stronger than monotonic strain hardening. The LCF behavior of the FSW joints have been described by the parameters of the Manson-Coffin-Basquin, taking into account the Smith-Watson-Topper parameter. The established fatigue parameters indicate that the joints produced with the 400–600 rpm tool rotation speed exhibit the lowest reduction in fatigue strength coefficient. The fractured surfaces have a typical fatigue striation pattern with the participation of secondary cracks and small Al2Cu particles.

Optimization of FSP parameters to fabricate AA7075-based surface composites using Taguchi technique and TOPSIS approach

Aluminum alloy-based surface composites processed by friction stir processing with enhanced hardness and impact energy is potentially suitable for aircraft and automotive applications. This behavior is improved by applying design of experiments (DOEs) in finding the suitable combination of process parameters. The influence of tool rotational speed, transverse speed, tilt angle, plunging depth and number of passes on hardness and impact energy are determined via Taguchi. It is identified that No. of pass plays a major contribution based on ANOVA. Single optimal parameter obtained through TOPSIS is employed to fabricate the composites with different volume ratios of WO3 and SiC particulates. Microstructural characterization of all the defect free surface composites depicts wide and homogenous dispersion of reinforcement particulates. Surface hybrid composite specimen comprising both WO3 and SiC particles significantly raises the microhardness to 214VHN attributed to the homogenous dispersion strengthening and grain boundary pinning mechanism. The specimen tends to show enhanced impact energy (12.3 J) due to extensive load bearing capacity of the reinforcements.

Influence of tool rotational speed on Microstructure and Mechanical Properties of Al-Li Alloy using Friction Stir Welding

Al-Li alloy is one of the suitable materials to be used in the aerospace industry due to its unique physical, mechanical, fatigue and corrosion resistance properties. The present study investigates the effect of rotational tool speed (TRS) on force and torque and its consequences on heat input, temperature, microstructure, and mechanical properties of a 5 mm thick 2050-T84 Al-Li alloy plates in square butt joint configuration. The investigation reveals defect-free welds at TRS ranging from 600 rpm to 1400 rpm. The grain size at nugget zone (NZ) and thermo-mechanically affected zone (TMAZ) increases (10.59 µm-16.79 µm; TMAZ-AS; 12.67µm-18.96 µm and TMAZ-RS; 12.22 µm-17.98 µm) with an increase in TRS (600–1400 rpm). The high ultimate tensile strength (UTS-410MPa) and % elongation (11.15%) was observed at 1400 rpm. With the help of scanning electron microscope (SEM) analysis of tensile fracture samples, the ductile nature of tensile fracture is observed.

Influence of tool rotational speed on the evolution of microstructure and mechanical properties of precipitation-hardened Aluminium 6061 butt joint during friction stir welding

The present investigation aims to evaluate the influence of varying tool rotational speed (rotation per minute, rpm) on the mechanical properties and microstructural evolution within friction stir welded aluminium alloyAA6061-T6 joints. The effects of rpm underthe constant tool travel speedwere investigated by optical microscopy, field emission scanning electron microscopy (FESEM)and transmission electron microscopy (TEM)observation, tensile, fracture and micro-hardness test. Special attention was paid to the formation and evolution ofprecipitates.Results revealed that the tool rotational speedof 1300 rpmproduces highest hardness reaching to ∼69 HVN at the nugget zone (NZ), which could be attributed to the higher intensity of nano-sized re-precipitation. This specific tool rotational speed of 1300 rpm has been determined to be suitable to achieve the maximum joint efficiency of 70.6%. Significantly, the NZ is characterized with small equiaxed dynamically recrystallized grains. In a noteworthy findings, the NZ showed mostly either free from strengthening precipitate or trace of small tiny re-precipitates, while the thermo-mechanically affected zone (TMAZ) contains coarse precipitates with deformed and dynamically recovered grains. On the other hand, there was obvious grain growth with increasing rpm, substantiating more heat involvement with favourable thermal gradient. The experiment concludes thatthe rotational speed has an considerable effect on the precipitation characteristics, dislocation property and existence of finer second phase intermetallic compounds (IMC),which arethe predominant factors controlling the joint property.

Influence of tool rotational speed on the microstructural characterization and mechanical properties of friction stir welded Al-Si10Mg parts produced by DMLS additive manufacturing process

Present study investigate the joining of precipitation hardened AlSi10Mg alloy, developed using direct metal laser sintering technique of additive manufacturing using friction stir welding. Consequently, three, single-pass, square butt-welded joints were fabricated from 3 mm thick plates of this alloy, using friction stir welding process at different tool rotational speeds (low, medium and high). Each welded joint was fabricated at the same transverse speed of 50 mm/min, H13 tool steel possessing scrolled shoulder and 3° tilt angle. Microstructural observations show a significant grain refinement within the stir zone, which reduced with the increase in tool rotational speed. This variation was accredited to the significant dynamic recrystallization in the weldment, and change in the morphology and size of the Si-particles. The transverse tensile test results show a considerable drop in the joint efficiency of the welds from ≈48% to ≈42% with the increase in tool rotational speed from low to high.

Effect of process parameters on friction stir welded joints of AA 7039

Friction Stir Welding is a new welding technique for joining high-strength aluminum alloys. In the recent years, the technology has already proved its presence in various industries like automobile, aviation, railways, marine, defense etc. Aluminum and its alloys are widely acceptable in structural applications, especially, AA 7039 is widely utilized in defense and marine industries. Friction Stir Welded joints usually does not exhibit the problems associated with the conventional welding techniques. The welding joints are highly influenced by the parameters involved in their fabrication. As a result, the purpose of this research is to investigate and characterize the influence of tool rotation speed and traverse speed (feed rate) on joining efficiency. Joint having weld configuration of 1000 RPM and 28 mm/min of feed rate shows highest tensile strength of 84.27% whereas lowest strength of 51.22% is recorded for the joint fabricated with 500 RPM and 56 mm of feed rate. Microhardness and microstructural features are investigated considering mechanical characteristics.

Experimental investigation of defect formation, microstructure and mechanical properties in friction stir welding of AA5086

The joint conditions of a weldment entirely rely on the set of process parameters applied during the welding operation. In friction stir welding (FSW), proper mechanical mixing of the material signifies the appropriate welding variables. The present work aspires to investigate the influence of tool rotational speed (RS), welding speed (WS) and plunge depth (PD) on external as well as internal defect formation, identify the different types of defect encountered during the FSW process, and evaluate the influence of different parameters on tensile properties and microstructure of the joints. In order to achieve the goal of the present work, a detailed experimental investigation was carried out using AA5086-O as base metal. On account of high strength-to-weight ratio, good weldability and high corrosion resistance, friction stir welded joints of aluminum alloys are widely applications in aerospace, automotive, railway and shipbuilding industry. It has been observed that theultimate tensile strength (UTS) of joint tends to decrease when there is increased in the welding speed at constant PD of 0.2 mm and RS of 1400 rpm. Similarly, with consistent PD of 0.3 mm and rotational speed of 2000 rpm, UTS of joints initially enhanced with an increment in welding speed and then reduced eventually. A joint fabricated with maximum rotation speed, intermediate welding speed and the higher plunge depth produced highest tensile strength of 215 MPa which is 16% higher than the conditions required for aerospace applications of FSW for aluminum alloys, as per the standard of American Welding Society (AWS). Microscopic analysis was conducted to scientifically ascertain the grain size, crystal structure and surface morphology of the FSW joints.

Effect of Al2O3 nanoparticles on microstructure and mechanical properties of friction stir-welded dissimilar aluminum alloys AA7075-T6 and AA6061-T6

In this research, a defect-free dissimilar weld joint of AA7075-T6 and AA6061-T6 reinforced with Al2O3 nanoparticles was fabricated via friction stir welding (FSW). The influence of tool rotational speed (700, 900 and 1100 rpm), traverse speed (40, 50 and 60 mm/min) with varying volume fractions of Al2O3 nanoparticles (4%, 7% and 10%) on microstructural evolution and mechanical properties were investigated. The augmentation of various mechanical properties is based on the homogeneity of particle dispersion and grains refinement in the SZ of the FSWed joint. The findings revealed that the remarkable reduction in grain size in the SZ was observed owing to the incorporation of Al2O3 nanoparticles produces the pinning effect, which prevents the growth of grain boundaries by dynamic recrystallization (DRX). The increasing volume fraction of Al2O3 nanoparticles enhanced the mechanical properties such as tensile strength, % elongation and micro-hardness. Agglomeration of particles was observed in the SZ of the FSWed joints produced at lower tool rotational speed of 700 rpm and higher traverse speed of 60 mm/min due to unusual material flow. Homogenous particle dispersion and enhanced material mixing ensue at higher rotational speed of 1100 rpm and lower traverse speed of 40 mm/min exhibit higher tensile strength and micro-hardness.

Metallurgical, mechanical and tribological behavior of Reinforced magnesium-based composite developed Via Friction stir processing

Reinforced magnesium metal matrix nanocomposites (MMMNCs) have piqued the interest of scientific community in recent years. Friction stir processing (FSP) is a known process to achieve the highest level of secondary phase nanocomposites distribution in the base monolithic matrix. In this study, an attempt has been made to synthesize magnesium base AZ61A/n-TiC nanocomposites using FSP and the influence of tool rotational speed on the metallurgical, mechanical, and tribological behavior of the developed composites has been studied. Microstructural examination shows that as tool rotational speed increases, high plastic deformation occurs and heat is generated along with the concomitant shattering impact of rotation, which consequently develops larger grains in the stir zone. However, this also provides thrusts resulting in uniform distribution of the nanoparticles in the base matrix. Microhardness and ultimate tensile strength of the developed nanocomposite were found to be significantly improved when contrasted with the base metal. Lower wear rate was observed for the composite developed at 800 rpm along with the abrasive type of wear mechanism.

Investigation into Mechanical Properties and Sliding Wear Behavior of Friction Stir Processed Surface Composite Material

One of the different and pioneering solid-state techniques, friction stir processing (FSP), is employed for the production of surface composites. In this research, the matrix selected was copper-nickel (CuNi) with hard boron carbide particle as reinforcement. The objective of the current research work is to produce reinforced 90/10 copper-nickel surface composites reinforced with B4C fabricated via FSP. The influence of tool rotational speed on macrostructure, microstructure, grain size analysis, microhardness, and wear studies of friction stir processed (FSPed) CuNi/B4C surface composites was assessed. For high rotational speed (1400 rpm) of stir tool, the modified surface area found is a maximum of 44.4 mm2 with uniform dispersion of hard particle reinforcement. The presence of hard particle in the surface area is revealed through the electron imaging and the spectroscopic results. Spectra mapping shows the uniform distribution of hard particle over the FSPed area, and the evidence is obtained with XRD analysis. From the experimentation, it is interesting to report that the reinforcements have decreased the surface hardness for an increased rotational speed of stir tool. The hardness recorded for minimum rotational speed is 223 HV which has gradually decreased to 178 HV for 1300 rpm. It has directly influenced the wear rate of modified FSPed, as hardness is directly proportional to wear behavior. The worn surface and fractured morphology of the CuNi/B4C surface composites were also studied using Field Emission Scanning Electron Microscope (FESEM).

Influence of tool rotational speed on mechanical properties of aluminium alloy AA 7075-T6 during friction stir welding process

ABSTRACT Influence of the rotational speed can be clearly seen by using field-emission scanning electron microscopy (FE-SEM). The influence of rotating speed on macro and microstructures, hardness, shear performance and failure mechanism of friction stir welding on AA7075-T6 Al alloy with a thickness of 5 mm was investigated. At the lowest rotational speed, the data show a significantly closer hardness distribution in the AA7075-T6 Al alloy plates used during the friction stir welding process. The presence of the Fe- compounds was observed in the fracture surface of the nugget zone through the microstructure analysis. In this experimental investigation H-13 steel tool is used for friction stir welding process.

Effect of Friction Stir Welding Techniques and Parameters on Polymers Joint Efficiency-A Critical Review.

The objective of current work is to analyse the influence of different welding techniques and welding parameters on the morphology and mechanical strength of friction stir welds (FSW) in polymers, based on data collected in the literature. In the current work, only articles that provide data on the joint efficiency, or sufficient information to estimate it are considered. The process using conventional tool is presented and compared with new procedures developed for FSW of polymers, such as those using tools with heated stationary shoulder, preheating of the polymer or double-side passage of the tool. The influence of tool rotational speed (w), welding speed (v), tilt angle and geometry of the pin are discussed. This work focuses on the polymers most studied in the literature, polyethylene (PE) and polypropylene (PP). The use of external heating and tools with stationary shoulder proved to be of great importance in improving the surface finish, reducing defects, and increasing the mechanical strength of the welds. The increase in the w/v ratio increased the joint efficiency, especially when using conventional tools on PE. A trend was obtained for conventional FSW, but it was difficult to establish mathematical relationships, because of the variability of welding conditions.

Finite Element Simulation of Friction Stir Welding of Inconel 718 to Nimonic 80A

This paper presents results of simulation of friction stir dissimilar welding of 5 mm thick, Nickel-based super-alloys, Inconel 718, and Nimonic 80A using Abaqus software. Four different trials were done to understand the influence of tool rotation speed on temperature distribution in weld zone while travel speed remains constant. The temperature in the weld zone was found to increase with the increase in tool rotation speed and travel speed. The temperature on the advancing side of the tool was higher than that of the retreating side. The tensile strength of weldment was found, by simulation, to be 25% more than that of base metal, Inconel 718. This may be due to grain refinement and dynamic recrystallization during FSW. The simulated bend test revealed an adequate level of ductility of weldments.