Friction stir butt-lap welding of A7N01P-T4 aluminum alloy: Efforts to mitigate defects and the resultant mechanical properties

2020 ◽  
Vol 234 (6) ◽  
pp. 873-880
Author(s):  
Rongzheng Xu ◽  
Zhicheng Wei ◽  
Jianbo Jiang ◽  
Yanxi Hou ◽  
Hui Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Rotational Speed ◽  
Plate Thickness ◽  
Base Material ◽  
Friction Stir ◽  
Tool Geometries ◽  
Tool Offset ◽  
Lap Welding

Butt-lap configuration of aluminum alloys was friction stir welded under various tool offsets, rotational speeds, and tool geometries. The tool offset was introduced to mitigate the inherent retreating side hook. As the probe was placed inwards, the retreating side hook was mitigated, but a severe S-line was formed. Since the inherent retreating side hook was difficult to further mitigate, the S-line was selected to be mitigated by increasing the rotational speed. But an excessive rotational speed (2000 r/min) could cause a severe upward-bending retreating side hook, which decreased the effective plate thickness. Subsequently, two-section stepped probes were employed to mitigate the defects. The S-line and retreating side hook were both mitigated and its ultimate tensile strength (369 MPa) reached 91% of the base material.

Microhardness and Microstructural Studies on Underwater Friction Stir Welding of 5052 Aluminum Alloy

2017 ◽  
Author(s):  
Srinivasa Rao Pedapati ◽  
Dhanis Paramaguru ◽  
Mokhtar Awang
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Plate Thickness ◽  
Base Material ◽  
Friction Stir ◽  
Underwater Friction Stir Welding ◽  
Void Area ◽  
Average Size ◽  
Microstructural Studies

As compared to normal Friction Stir Welding (FSW) joints, the Underwater Friction Stir Welding (UFSW) has been reported to be obtainable in consideration of enhancement in mechanical properties. A 5052-Aluminum Alloy welded joints using UFSW method with plate thickness of 6 mm were investigated, in turn to interpret the fundamental justification for enhancement in mechanical properties of material through UFSW. Differences in microstructural features and mechanical properties of the joints were examined and discussed in detail. The results indicate that underwater FSW has reported lower hardness value in the HAZ and higher hardness value in the intermediate of stir zone (SZ). The average hardness value of underwater FSW increases about 53% greater than its base material (BM), while 21% greater than the normal FSW. The maximum micro-hardness value was three times greater than its base material (BM), and the mechanical properties of underwater FSW joint is increased compared to the normal FSW joint. Besides, the evaluated void-area fraction division in the SZ of underwater FSW joint was reduced and about one-third of the base material (BM). The approximately estimated average size of the voids in SZ of underwater FSW also was reduced to as low as 0.00073 mm2, when compared to normal FSW and BM with approximately estimated average voids size of 0.0024 mm2 and 0.0039 mm2, simultaneously.

An investigation on the mechanical properties of friction stir welded polycarbonate/aluminium oxide nanocomposite sheets

2016 ◽  
Vol 49 (6) ◽  
pp. 498-512 ◽  
Author(s):  
Ali Doniavi ◽  
Saeedeh Babazadeh ◽  
Taher Azdast ◽  
Rezgar Hasanzadeh
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Rotational Speed ◽  
Signal To Noise Ratio ◽  
Base Material ◽  
Travel Speed ◽  
Effective Parameter ◽  
Welding Parameters ◽  
Effective Parameters ◽  
Friction Stir

Although considerable progress has been made in recent years in field of polymer welding, challenges still remain in using a friction stir welding method to join polycarbonate (PC) composites. This research provides an investigation on the effect of welding parameters (tool’s travel and rotational speeds) on mechanical properties of PC nanocomposite weld lines. PC nanocomposites were prepared with different percentages of Al2O3 nanofiller using a twin screw extruder and injection moulded as sheets in order to ease the welding. Considering various parameters and their levels, optimization of Taguchi experimental design was carried out, an L16 orthogonal standard array was selected and the effective parameter was calculated using analysis of variance of the results. The results indicated that nanoalumina percentage is the most effective parameter on the tensile strength of weld and tool’s travel speed and rotational speed are next effective parameters, respectively. According to signal-to-noise ratio, maximum weld tensile strength (89.5% of base material) is revealed when nanoalumina percentage, tool’s travel speed and tool’s rotational speed were chosen as 1 wt%, 12 mm/min and 1250 r/min, respectively.

Microstructure and Cryogenic Mechanical Properties of AA5083 Joints Prepared by Friction Stir Welding

2014 ◽  
Vol 788 ◽  
pp. 243-248 ◽  
Author(s):  
Bao Kang Gu ◽  
Da Tong Zhang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Tensile Testing ◽  
Base Material ◽  
Tensile Behavior ◽  
Planar Slip ◽  
Friction Stir ◽  
5083 Aluminum Alloy ◽  
Cryogenic Mechanical Properties

In this study, 5083 aluminum alloy plates with a thickness of 3mm are friction stir welded and the microstructure and mechanical properties of the joints were characterized. In particular, tensile behavior of the joints is examined at 77K. It is found that defect-free joints can be obtained under a tool rotational rate of 800rpm and a welding speed of 60mm/min. The friction stirring welds exhibit finer microstructure and higher hardness than that of the base material due to the grain refinement. The ultimate tensile strength (UTS) and elongation of the joints measured at 298K are 316MPa and 21.3%, which are nearly equal to those of the base material. With the tensile test temperature decreasing to 77K, UTS and elongation of both the base material and joints increase. Comparing with tensile testing at 298K, dimples on the fracture surface of the samples tested at 77K are more uniform in distribution. The improvement of the mechanical properties of specimens at low temperature is related to the inactivation of planar slip and the strengthening of strain hardening.

Effect of Pre and Post Weld Heat Treatment on the Mechanical Properties of Friction Stir Welded AA6061-T6 Joint

2020 ◽  
Vol 17 (2) ◽  
pp. 7882-7889 ◽  
Author(s):  
J.C. Verduzco Huarez ◽  
R. Garcia Hernandez ◽  
G. M. Dominguez Almaraz ◽  
J.J. Villalón López
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Research Work ◽  
Base Material ◽  
Welding Process ◽  
Post Weld Heat Treatment ◽  
Friction Stir

This research work focuses on the study of the improvement of mechanical properties, specifically the tensile strength of 6061-T6 aluminum alloy on prismatic specimens with 9.5 mm thickness that has been subjected to friction stir welding process and two heat treatments; solubilized and aging before or after the welding process. Three cases studied and evaluated were, welding of the base material without heat treatment (BMW), solubilized heat treatment and partial aging of the base material before welding (HTBW), and heat treatment of solubilized and aging of the base material after welding (HTAW). The obtained results show an increase of about 10% (20 MPa) of tensile strength for the HTBW process, compared to BMW case. In addition, for the case of HTAW, the obtained tensile resistance presents a joint efficiency of 96%, which is close to the tensile strength of the base material (»310 MPa).

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

2021 ◽  
pp. 095440892110655
Author(s):  
Sumit Jain ◽  
R.S. Mishra
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Rotational Speed ◽  
Traverse Speed ◽  
Particle Dispersion ◽  
Al2o3 Nanoparticles ◽  
Tool Rotational Speed ◽  
Micro Hardness ◽  
Friction Stir ◽  
Dissimilar Aluminum Alloys

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.

Evaluating the Strength of the Friction Stir Welded Joints at Various Rotational Speeds

2013 ◽  
Vol 446-447 ◽  
pp. 312-315
Author(s):  
Ramaraju Ramgopal Varma ◽  
Abdullah Bin Ibrahim ◽  
B. Ravinder Reddy
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Friction Stir Welding ◽  
Yield Strength ◽  
Welded Joints ◽  
Rotational Speed ◽  
Testing Machine ◽  
Friction Stir ◽  
Universal Testing ◽  
Welding Technique

The present research paper aims in evaluating the strength of the welded AA6351 alloy plates of 6 mm thick by using friction stir welding technique at different rotational speeds The applied welding technique is capable of achieving the mechanical properties of the alloy close to that of the original alloy. In the present investigation, the speeds of the spindle were varied from 1100 rpm to 1500 rpm with a constant transverse speed of 20 mm/min. The tensile strength of the joints is determined by an universal testing machine. The results from the present investigation show that the values of the yield strength were very much closer to the values of the AA6351Alloy prior to welding. It has been found from the experiments that the strength of the joints increases with the increase in the rotational speed; however, the same is decreasing after achieving certain speed.

Wear and Mechanical Properties of Aluminum Alloy Based Hybrid Composites [(SiC+Gr) and (SiC+Al2O3)] Fabricated by Friction Stir Processing

2013 ◽  
Author(s):  
A. Kumar ◽  
A. Devaraju ◽  
B. Kotiveerachari
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Friction Stir Processing ◽  
Rotational Speed ◽  
Solid Lubricant ◽  
Hybrid Composites ◽  
Optical Microscope ◽  
High Wear Resistance ◽  
Nugget Zone ◽  
Friction Stir

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.

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