Abstract: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… Show more
“…They found that it was due to the flow of the material from the top to bottom (i.e. warmer to colder) beneath the NZ or due to insufficient heat generation and partial recrystallization occurring in the nugget zone during the FSW process [94][95][96][97][98].…”
Fusion welding processes do not find attention due to their restriction to use for certain grades of materials and alloys. Friction Stir welding (FSW) or the solid-state joining process has proven to be a more efficient process for the welding of metal-matrix reinforced composite butt joints by employing various combinations of reinforcement particles and base matrices compared to the fusion welding process. Due to the solid-state nature of the FSW process, no melting of base material would occur which leads to no toxic fumes, low energy consumption, environmentally friendly, and ease of operation that makes FSW a more versatile welding process for aerospace, automobile, and transportation industries. However, the challenges in joining metal matrix reinforced composites remain even with a substantial advancement in the process made during current years. This review article outlines a brief overview of the state of art of metal matrix reinforced welds joined using FSW. More emphasis with critical evaluation has been done on the (a) macrostructural and microstructural characteristics of a metal matrix reinforced welds which merely depend on the plasticized material flow and reinforcement particles behavior and its difficulty for uniform distribution of reinforcement particles in the weld zone based on the combination of reinforcement particles and the metal matrix materials, (b) assessment of mechanical properties of the metal matrix reinforced welds those are directly interdependent on the selection of process parameters by which the grain refinement and their reinforcement particles distribution depend that leads to changes in such properties, and (c) fracture and wear properties of the metal matrix reinforced welds which again depends on the reinforcement particles and the metal matrix materials combination. The conclusions of this review are ended up with recommendations for the directions for future research.
“…They found that it was due to the flow of the material from the top to bottom (i.e. warmer to colder) beneath the NZ or due to insufficient heat generation and partial recrystallization occurring in the nugget zone during the FSW process [94][95][96][97][98].…”
Fusion welding processes do not find attention due to their restriction to use for certain grades of materials and alloys. Friction Stir welding (FSW) or the solid-state joining process has proven to be a more efficient process for the welding of metal-matrix reinforced composite butt joints by employing various combinations of reinforcement particles and base matrices compared to the fusion welding process. Due to the solid-state nature of the FSW process, no melting of base material would occur which leads to no toxic fumes, low energy consumption, environmentally friendly, and ease of operation that makes FSW a more versatile welding process for aerospace, automobile, and transportation industries. However, the challenges in joining metal matrix reinforced composites remain even with a substantial advancement in the process made during current years. This review article outlines a brief overview of the state of art of metal matrix reinforced welds joined using FSW. More emphasis with critical evaluation has been done on the (a) macrostructural and microstructural characteristics of a metal matrix reinforced welds which merely depend on the plasticized material flow and reinforcement particles behavior and its difficulty for uniform distribution of reinforcement particles in the weld zone based on the combination of reinforcement particles and the metal matrix materials, (b) assessment of mechanical properties of the metal matrix reinforced welds those are directly interdependent on the selection of process parameters by which the grain refinement and their reinforcement particles distribution depend that leads to changes in such properties, and (c) fracture and wear properties of the metal matrix reinforced welds which again depends on the reinforcement particles and the metal matrix materials combination. The conclusions of this review are ended up with recommendations for the directions for future research.
“…5b. This demonstrates that one FSW pass was not producing su cient strain to prevent clustering of SiCp [30]. The clustering of SiCp was found absent as the FSW passes enhanced from one to two, but the dispersion pattern of SiCp was observed as non-uniform in the two-passes FSWed reinforced joint, as cited in Fig.…”
In the current research, the in uence of multi-pass (one, two and three passes) of friction stir welding and SiC microparticles on the tensile strength, microhardness and %strain of dissimilar reinforced joints of AA6082 and AA5083 was examined. Tool rotating speed of 900 rpm, transverse speed of 45 mm/min, tool tilt angle of 2º and 8% volume percentage of SiC microparticles were considered as constant parameters for multi-pass FSW. The nding demonstrated that increasing the number of FSW passes from one to three augmented the dispersion pattern of Sic microparticles. The grain re nement of multipass reinforced joints was achieved by the pinning effect of SiC microparticles and dynamic recrystallization. The three-passes FSWed reinforced joint exhibited the highest tensile strength (247.17 MPa), %stain (13.1%) and microhardness (126.6 HV) due to the higher grain re nement.
“…53 Smaller grain size exhibits higher hardness as per Hall–Petch relationship. 54–56 Figure 11.Micro-hardness profile of composite Joints, (a) at 700rpm, (b) at 900 rpm, (c) 1100 rpm.…”
Section: Resultsmentioning
confidence: 99%
“…53 Smaller grain size exhibits higher hardness as per Hall-Petch relationship. [54][55][56] The micro-hardness of the composite joints embedded with reinforcement particles also enhanced due to the presence of hard Al 2 O 3 particles. Therefore, the strengthening impact of Al 2 O 3 mp in specimen no-12 was observed higher in comparison with other specimens, due to the increased volume fraction of hard Al 2 O 3 mp, higher grain refinement, and enhanced material mixing rule.…”
Section: Influence Of Al 2 O 3 Mp On Tensile Strengthmentioning
In the present study, the fabrication of dissimilar composite joints of AA6061/AA7075 incorporated with micro-sized Al2O3 particles was carried out using friction stir welding. The impact of the dispersion pattern of different volume fractions of Al2O3 micro-particles (Al2O3mp) under various combinations of tool rotational speed (RS) and traverse speed (TS) on the weld quality was studied. The composite joints were tested for tensile strength, micro-hardness, wear, and microstructural development. The results demonstrated that higher grain refinement due to dynamic recrystallization (DRX) and pinning effect of Al2O3mp considerably improved the weld quality. Higher improvements in the mechanical properties of the composite joints were also observed as the volume fraction of Al2O3mp increased. Consequently, the composite joint processed at RS of 1100 rpm, TS of 40 mm/min with 10% volume fraction of Al2O3mp exhibits the higher tensile strength of 241.35 MPa with joint efficiency of 83.80% and maximum micro-hardness of 157.5 HV. In comparison with base materials, the incorporation of Al2O3mp also improved the wear resistance of the composite joints.
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