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.

Microstructure, Texture and Mechanical Properties of Al Alloy A380 Prepared by Directional Solidification Method

2019 ◽  
Vol 287 ◽  
pp. 18-23
Author(s):  
Hemant Borkar ◽  
Salem Seifeddine ◽  
Anders E.W. Jarfors
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Directional Solidification ◽  
Solidification Rate ◽  
Al Alloy ◽  
Secondary Dendrite Arm Spacing ◽  
Β Phase ◽  
Cu Alloy ◽  
Eutectic Si ◽  
The One

The mechanical properties of Al-Si alloys are affected by several microstructural features such as secondary dendrite arm spacing (SDAS), size and shape of eutectic Si-particles, presence of intermetallics as well as by porosity. In the current study, Al-Si-Cu alloy A380 was prepared by a unique directional solidification method to produce samples with two different SDAS of 9 μm and 27 μm. The lower solidification rate resulted in larger SDAS, larger grain size, larger eutectic Si and larger intermetallics including Fe-rich β phase. The microstructure with higher solidification rate was found to be finer and more homogeneous with smaller eutectic Si and intermetallics. The specimen with larger SDAS exhibited stronger texture than the one with smaller SDAS. The specimen with smaller SDAS showed improved mechanical properties including YS, UTS and ductility.

scholarly journals Microstructural Evolution and Mechanical Properties of Friction Stir Welded Butt Joints of 5A06 Alloy Ultra-Thin Sheets

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3906 ◽  
Author(s):  
Yang Han ◽  
Xiaoqing Jiang ◽  
Tao Yuan ◽  
Shujun Chen ◽  
Dongxiao Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Grain Boundaries ◽  
Microstructural Evolution ◽  
Welding Speed ◽  
Base Material ◽  
Thin Plates ◽  
Al Alloy ◽  
Minimum Thickness ◽  
Friction Stir

Ultra-thin plates have great potential for applications in aircraft skin, the packaging industry, and packaging of electronic products. Herein, 1 mm-thick 5A06 Al alloy was welded with friction stir welding. The microstructural evolution of the welds was investigated in detail with optical microscopy, scanning electron microscopy, and electron backscatter diffraction. The results showed that the friction stir welds of 1 mm-thick 5A06 Al alloy were well formed without obvious defect and with a minimum thickness reduction of 0.025 mm. Further, the grain size and the proportion of low-angle grain boundaries decreased with decreasing welding speed, because of the increasing degree of dynamic recrystallization. Among all of the welded joints, the welding speed of 100 mm/min yielded the smallest grain size and the highest proportion of high-angle grain boundaries, and thus the best mechanical properties. Specifically, the tensile strength of the joint was greater than that of the base material, while the elongation reached 80.83% of the base material.

Effect of Welding Speed on Mechanical Properties of Friction Stir Welded AA 6082-T6 Al Alloy

2018 ◽  
Vol 877 ◽  
pp. 98-103
Author(s):  
Dhananjayulu Avula ◽  
D.K. Dwivedi
Keyword(s):  
Tensile Strength ◽  
Welding Speed ◽  
Welded Joint ◽  
Al Alloy ◽  
Microstructural Properties ◽  
Nugget Zone ◽  
Percentage Elongation ◽  
Friction Stir ◽  
Mechanical And Microstructural Properties ◽  
Hardness Values

In this study the effect of process parameters on mechanical and microstructural properties of similar AA6082-T6 joints produced by friction stir welding was investigated. Different samples were produced by varying the transverse welding speeds of the tool from 19 to 75 mm/min and a fixed rotational speed of 635 rpm. A more uniform hardness values in the nugget zone were observed at 48 mm/min welding speed. The lowest hardness values were recorded on nugget zone at all the welding speeds. The increase in welding speed increases ultimate tensile strength and reaches maximum and further increase in welding speed results decrease in tensile strength were observed. The welded joint has highest joint efficiency (52.33 %) obtained at the welding speed of 48 mm/min. Similarly with the increase in welding speed decrease in the percentage elongation were recorded.

Transition from Superplastic Behavior - Viscous Glide - Dislocation Climb - Power-Law Break down Regimes in Friction Stir Processed AA5083

2016 ◽  
Vol 863 ◽  
pp. 23-30
Author(s):  
Ehab A. El-Danaf ◽  
Mahmoud Soliman ◽  
Magdy M. El Rayes
Keyword(s):  
Grain Size ◽  
Feed Rate ◽  
Rate Sensitivity ◽  
Grain Boundary Sliding ◽  
Lattice Diffusion ◽  
Al Alloy ◽  
Experimental Conditions ◽  
Friction Stir ◽  
Grain Sizes ◽  
True Activation Energy

5083 Al alloy was friction stir processed (FSP) at room temperature under various experimental conditions. Two rotational speeds of 430 and 850 rpm with a single traverse feed of 90 mm/min (430-90, 850-90) were used, to investigate the effect of rotation speed. Also, another feed rate of 140 mm/min was used with a rotational speed of 430 rpm (430-140), to investigate the effect of feed rate. The processing conditions resulted in three different grain sizes of 0.95, 1.6 and 2.6 μm depending on the FSP parameters. The deformation behavior of the FSP samples was investigated at 250 C at three strain rates of 10-4, 10-3 and 10-2 s-1. The values of strain rate sensitivity, m was determined, as a function of grain size, and it decreased from 0.45 to 0.33 to 0.18 with increasing the grain size. True activation energy was calculated as 63, 95, 157 kJ/mole for the grain sizes of 0.95, 1.6 and 2.6 μm, respectively. These calculated values are comparable to grain boundary sliding of magnesium in aluminum (69 – 78 kJ mol-1), magnesium in aluminum (~115 kJ mole-1) and aluminum lattice diffusion (~143 kJ mol-1 ). The change in the deformation mechanism with grain size was discussed in some details.

The Skin Effect in an Mg-RE High Pressure Die Cast Alloy

2010 ◽  
Vol 654-656 ◽  
pp. 691-694 ◽  
Author(s):  
K. Yang ◽  
A.V. Nagasekhar ◽  
Carlos H. Cáceres ◽  
Mark Easton
Keyword(s):  
Grain Size ◽  
Skin Effect ◽  
Cast Alloy ◽  
Core Region ◽  
Casting Surface ◽  
Cross Sectional ◽  
The Core ◽  
Die Cast ◽  
Segregation Band ◽  
Hardness Values

Cross-sectional microhardness maps of cast-to-shape flat tensile specimens have been obtained for a binary Mg-3.44 mass% La alloy. Higher microhardness numbers were generally found near the casting surface, at the corners and along the segregation band. The higher hardness values were ascribed to the finer solidification microstructure near the surface and to localized positive macro segregation. The majority of lower hardness numbers was found at the core region. Lower hardness values were ascribed to the coarser grain size prevalent at the core and to dispersed microporosity. The non uniformity of the harder surface layer in both depth and hardness appeared related to local homogeneities in the grain size distribution caused by the scattered presence of large externally solidified grains.

scholarly journals Metallographic organization and tensile properties of FSSP-modified H62 copper alloy surface

2020 ◽  
Vol 29 ◽  
pp. 2633366X2092702
Author(s):  
Weiwei Song ◽  
Xiaojing Xu ◽  
Shengrong Liu ◽  
Jiafei Pu ◽  
Hongfeng Wang
Keyword(s):  
Grain Size ◽  
Base Metal ◽  
Copper Alloy ◽  
Boundary Region ◽  
Alloy Sheet ◽  
Alloy Surface ◽  
Surface Processing ◽  
Friction Stir ◽  
Equiaxed Grains ◽  
Hardness Values

In this study, the surface of friction stir surface processing (FSSP)-modified copper alloy was altered by different passes of modification and lower pressure after selecting FSSP process parameters. The results showed that the grain size of the modified copper alloy surface was refined under various processes. In the modified section, the grains changed from fine equiaxed grains to rolling strips from the surface layer to the bottom of copper alloy sheet. FSSP could change the surface metallographic organization but could not change the internal structure of the sheet. The hardness values of samples obtained under various processes were higher than those of base metal, but the hardness of modified boundary region was slightly lower than that of base metal. The tensile strength of samples obtained under various processes was higher than that of base metal. Among them, FSSP was the best after one pass of modification, followed by two passes, and the worst was three passes. Most of the stretches appeared on the advancing side, and only a few appeared on the retreating side. The tensile parts had a honeycomb-type morphology, with a ductile fracture mode.

Evaluation of microstructure and superplasticity in friction stir processed 5083 Al alloy

2004 ◽  
Vol 19 (11) ◽  
pp. 3329-3342 ◽  
Author(s):  
I. Charit ◽  
R.S. Mishra
Keyword(s):  
Grain Size ◽  
Strain Rate ◽  
Solute Drag ◽  
Tensile Tests ◽  
Grain Boundary Sliding ◽  
Al Alloy ◽  
Dislocation Glide ◽  
Friction Stir ◽  
Fine Grained ◽  
5083 Al Alloy

Friction stir processing (FSP) has been developed as a potential grain refinement technique. In the current study, a commercial 5083 Al alloy was friction stir processed with three combinations of FSP parameters. Fine-grained microstructures with average grain sizes of 3.5–8.5 μm were obtained. Tensile tests revealed that the maximum ductility of 590 was achieved at a strain rate of 3 × 10−3 s−1 and 530 °C in the 6.5-μm grain size FSP material, whereas for the material with 8.5-μm grain size, maximum ductility of 575 was achieved at a strain rate of 3 × 10−4 s−1 and490 °C. The deformation mechanisms for both the materials were grain boundary sliding (m ∼0.5) However, the 3.5-μm grain size material showed maximum ductility of 315 at 10−2 s−1 and 430 °C. The flow mechanism was solute-drag dislocation glide (m ∼0.33) This study indicated that establishing a processing window is crucial for obtaining optimized microstructure for optimum superplasticity.

Control of Grain Size and Texture in Al Alloys Utilizing Friction Stir Processing

2007 ◽  
Vol 539-543 ◽  
pp. 3769-3774 ◽  
Author(s):  
Toshiya Shibayanagi ◽  
Masaaki Naka
Keyword(s):  
Grain Size ◽  
Aluminum Alloys ◽  
Grain Refinement ◽  
Grain Growth ◽  
Rotation Speed ◽  
Al Alloys ◽  
Abnormal Grain Growth ◽  
Texture Development ◽  
Al Alloy ◽  
Friction Stir

The present paper deals with the control of microstructure of friction stir processed aluminum alloys focusing on grain refinement, thermal stability at elevated temperature and texture development in some aluminum alloys such as 5083, 6061 and 7075 commercial aluminum alloys. 3mm thickness plates of 5083, 6061 and 7075 Al alloys were friction stir processed/welded with several rotation speeds and travelling speeds. Optical microscopy revealed the grain refinement in the stirred zone of each alloy and the average grain size decreased with decreasing rotation speed under various travelling speeds. Annealing of the joints brought about abnormal grain growth at temperatures higher than 773K for 5083 alloy. Critical temperature of the abnormal grain growth tended to decrease as the rotation speed decreased for the fixed travelling speed. Dissimilar joining of 5083 Al alloy to 6061 Al alloy also showed abnormal grain growth when annealed at 773K. A peculiar texture development of 7075 Al joint showing (111)//ND-oriented grains existing throughout the nugget was revealed by EBSP analysis.

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.

scholarly journals Preparation of high-entropy carbides by different sintering techniques

2021 ◽  
Vol 56 (19) ◽  
pp. 11237-11247 ◽  
Author(s):  
Johannes Pötschke ◽  
Manisha Dahal ◽  
Mathias Herrmann ◽  
Anne Vornberger ◽  
Björn Matthey ◽  
...  
Keyword(s):  
Grain Size ◽  
Single Phase ◽  
X Ray Diffraction ◽  
Vacuum Sintering ◽  
X Ray ◽  
High Entropy ◽  
Mean Grain Size ◽  
The Mean ◽  
Gas Pressure Sintering ◽  
Hardness Values

AbstractDense (Hf, Ta, Nb, Ti, V)C- and (Ta, Nb, Ti, V, W)C-based high-entropy carbides (HEC) were produced by three different sintering techniques: gas pressure sintering/sinter–HIP at 1900 °C and 100 bar Ar, vacuum sintering at 2250 °C and 0.001 bar as well as SPS/FAST at 2000 °C and 60 MPa pressure. The relative density varied from 97.9 to 100%, with SPS producing 100% dense samples with both compositions. Grain size measurements showed that the substitution of Hf with W leads to an increase in the mean grain size of 5–10 times the size of the (Hf, Ta, Nb, Ti, V,)C samples. Vacuum-sintered samples showed uniform grain size distribution regardless of composition. EDS mapping revealed the formation of a solid solution with no intermetallic phases or element clustering. X-ray diffraction analysis showed the structure of mostly single-phase cubic high-entropy carbides. Hardness measurements revealed that (Hf, Ta, Nb, Ti, V)C samples possess higher hardness values than (Ta, Nb, Ti, V, W)C samples.

Sign in / Sign up

Export Citation Format

Share Document