Tensile Fracture Behavior of Friction Stir Processed Al-7Si-0.3Mg Cast Alloy

2012 ◽  
Vol 706-709 ◽  
pp. 971-976 ◽  
Author(s):  
Zhan W. Chen ◽  
Francis Abraham ◽  
Joshua Walker
Keyword(s):  
Fracture Behavior ◽  
Rotation Speed ◽  
Cast Alloy ◽  
Tensile Elongation ◽  
Tensile Fracture ◽  
Cast Material ◽  
Friction Stir ◽  
Cast Alloys ◽  
High Rotation Speed ◽  
Zone Pass

Elimination of porosity and refinement of the normally coarse cast microstructure ofaluminium cast alloys by the intensive plastic deformation during friction stir processing (FSP) iswell known. However less is known about the mechanical behavior of the FS processed regionwhich contains zone/pass boundaries and macro/microstructure segregations. In the present study ofFS processed cast Al-7Si-0.3Mg alloy, microstructures featuring the deformed α-Al, fragmented Siparticles and their distribution in the processed region were related to the fracture paths duringtensile testing. It has been found that under the condition of a high rotation speed and minimum pinoverlap there is a strong upward flow of deformed cast material in thermomechanial affected zone.The arrays of Si particles in that flow have provided favorable paths for crack propagation duringtensile testing. As a result, tensile elongation and thus UTS values are low. The mechanism of thatupward flow and FSP conditions for reducing the flow and thus for improving properties of theprocessed region are discussed.

EFFECT OF FRICTION STIR PROCESSING CONDITION ON TENSILE PROPERTIES OF Al-7Si-0.3Mg CAST ALLOY

2012 ◽  
Vol 06 ◽  
pp. 397-400
Author(s):  
Z.W. Chen
Keyword(s):  
Tensile Properties ◽  
Friction Stir Processing ◽  
Material Flow ◽  
Rotation Speed ◽  
Cast Alloy ◽  
Processing Condition ◽  
Flow Mechanism ◽  
Friction Stir ◽  
High Elongation ◽  
High Rotation Speed

Multipass friction stir processing (FSP) of cast Al -7 Si -0.3 Mg alloy was conducted and FS microstructures were related to the fracture paths and tensile properties. It has been found that high rotation speed (ω) FS caused alignments of Si particles, providing easy paths for fracturing during loading and resulting in low elongation and lower UTS values of the processed alloy. The material flow mechanism during FS leading to the alignments is suggested. This suggested mechanism has been verified after conducting FS experiments using a lower ω value which eliminated Si particle alignments and thus allowed high elongation and UTS values to be attained.

Effect of Warm Deforming and Heat Treating on Microstructure and Mechanical Properties of Mg-Zn-Zr Magnesium Alloy

2012 ◽  
Vol 472-475 ◽  
pp. 707-711
Author(s):  
Guan Lu ◽  
Ya Qin Yang ◽  
Bao Cheng Li ◽  
Zhi Min Zhang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Cast Alloy ◽  
Hot Extrusion ◽  
Heat Treating ◽  
Optical Microscope ◽  
Tensile Fracture ◽  
Strengthening Effect ◽  
Zk60 Alloy ◽  
Cast Alloys

In this paper, the effects of hot extrusion and T5、T6 heat treatment on the microstructures and mechanical properties of ZK60 magnesium alloys are investigated by optical microscope, electronic scanning microscope and mechanical testers. The result shows that both the tensile strength and the elongation of the ZK60 alloy extruded at 380°Care much higher than that of the as-cast alloys, as there are much granular second phases precipitated during the extrusion. The tensile strength of the extruded and T5 treated alloy increases while the elongation decreases faster than that of the extruded alloy. The strengthening effect of the T6 treatment is inferior to that of the T5 treatment. The tensile fracture of the as-cast alloy is brittle fractured while that of the extruded and T5 treated alloy is ductile fractured with lots of deep and even dimples.

The Influence of Welding Parameters on Tensile Behavior of Friction Stir Welded Al 2024-T4 Joints

2009 ◽  
Vol 83-86 ◽  
pp. 1197-1204
Author(s):  
E. Mahmudi ◽  
Hassan Farhangi
Keyword(s):  
Rotation Speed ◽  
Tensile Behavior ◽  
Tensile Fracture ◽  
Welding Parameters ◽  
Speed Ratio ◽  
Rotating Speed ◽  
Friction Stir ◽  
Fracture Location ◽  
Band Spacing ◽  
Al 2024

In the present study, the relationships between friction stir welding parameters and the tensile behavior of Al 2024-T4 joints was investigated. The aluminum alloy plates were butt-welded using a hardened steel tool with a threaded and fluted cylindrical pin at various tool rotation speed to advancing speed ratios. Metallographic observations, EDS analysis and microhardness measurements show that the band spacing in the periodic microstructure of the stir zone and the average microhardness of this region decrease with increasing speed ratio. Tensile ductility is strongly affected by welding parameters and final elongation increases significantly with speed ratio at the constant rotating speed of 900 rpm. This behavior is found to be associated with a change in tensile fracture location. Formation of microscopic voids at low speed ratios leads to premature fracture in the nugget zone, while in the defect-free joints produced at higher speed ratios the fracture location shifts into the HAZ on the retreating side, which exhibits the lowest microhardness value within the weld joint. At the optimum rotation speed of 900 rpm and speed ratio of 11.2 rev/mm the tensile strength and final elongation of the joints are equivalent to 97% and 77% that of base metal, respectively.

scholarly journals The Applicability of Die Cast A356 Alloy to Additive Friction Stir Deposition at Various Feeding Speeds

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6018
Author(s):  
Bandar Alzahrani ◽  
Mohamed M. El-Sayed Seleman ◽  
Mohamed M. Z. Ahmed ◽  
Ebtessam Elfishawy ◽  
Adham M. Z. Ahmed ◽  
...  
Keyword(s):  
Grain Size ◽  
Cast Alloy ◽  
A356 Alloy ◽  
Deposition Process ◽  
Al Alloy ◽  
Cast Material ◽  
Mean Values ◽  
Friction Stir ◽  
Eutectic Si ◽  
Hardness Values

In the current investigation, additive friction stir-deposition (AFS-D) of as-cast hypoeutectic A356 Al alloy was conducted. The effect of feeding speeds of 3, 4, and 5 mm/min at a constant rotational speed of 1200 rpm on the macrostructure, microstructure, and hardness of the additive manufacturing parts (AMPs) was investigated. Various techniques (OM, SEM, and XRD) were used to evaluate grain microstructure, presence phases, and intermetallics for the as-cast material and the AMPs. The results showed that the friction stir deposition technique successfully produced sound additive manufactured parts at all the applied feeding speeds. The friction stir deposition process significantly improved the microstructure of the as-cast alloy by eliminating porosity and refining the dendritic α-Al grains, eutectic Si phase, and the primary Si plates in addition to intermetallic fragmentation. The mean values of the grain size of the produced AMPs at the feeding speeds of 3, 4, and 5 mm/min were 0.62 ± 0.1, 1.54 ± 0.2, and 2.40 ± 0.15 µm, respectively, compared to the grain size value of 30.85 ± 2 for the as-cast alloy. The AMPs exhibited higher hardness values than the as-cast A356 alloy. The as-cast A356 alloy showed highly scattered hardness values between 55 and 75.8 VHN. The AMP fabricated at a 3 mm/min feeding speed exhibited the maximum hardness values between 88 and 98.1 VHN.

scholarly journals Influences of Pin Shape on a High Rotation Speed Friction Stir Welding Joint of a 6061-T6 Aluminum Alloy Sheet

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 987 ◽  
Author(s):  
Yang Zhou ◽  
Shujin Chen ◽  
Jiayou Wang ◽  
Penghao Wang ◽  
Jingyu Xia
Keyword(s):  
Friction Stir Welding ◽  
Aluminium Alloy ◽  
Rotation Speed ◽  
Alloy Sheet ◽  
Aluminum Alloy Sheet ◽  
Welding Quality ◽  
Nugget Zone ◽  
Friction Stir ◽  
High Rotation Speed ◽  
S Curve

In order to explore the influences of different pins on the weld based on the specialty of the aluminium alloy sheet welding, three kinds of pins were chosen to perform high rotation speed friction stir welding on a 1 mm thick 6061-T6 aluminium alloy in this study. The microstructure and mechanical properties of the joints were analysed at the same time. When the rotation speed was 11,000 rpm and the welding speed was 300 mm/min, more sufficient stirring and a better joint (the tensile strength reaches 87.2% of the base metal) can be obtained with the pin design of a quadrangular frustum pyramid. The pattern of the weld cross section was a “flat T” and no obvious “S curve” was found in nugget zone (NZ). Heat affected zone (HAZ) and thermo-mechanically affected zone (TMAZ) were also narrow. The results demonstrate that the proportion of low angle boundaries in each area of the weld is lower than that of traditional Friction Stir Welding (FSW). The grain size of NZ is significantly refined and the proportion of low angle boundaries is only 20.1%, which have improved the welding quality.

Friction stir welding of 2060–T8 Al-Li alloy. Part II: Tensile fracture behavior

2020 ◽  
Vol 168 ◽  
pp. 110507
Author(s):  
Y. Tao ◽  
Z. Zhang ◽  
B.H. Yu ◽  
P. Xue ◽  
D.R. Ni ◽  
...  
Keyword(s):  
Friction Stir Welding ◽  
Fracture Behavior ◽  
Tensile Fracture ◽  
Friction Stir ◽  
Alloy Part
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