Achieving ultrafine grain size in Mg–Al–Zn alloy by friction stir processing

2007 ◽  
Vol 57 (3) ◽  
pp. 209-212 ◽  
Author(s):  
C.I. Chang ◽  
X.H. Du ◽  
J.C. Huang
Keyword(s):  
Grain Size ◽  
Friction Stir Processing ◽  
Ultrafine Grain ◽  
Friction Stir ◽  
Ultrafine Grain Size ◽  
Zn Alloy

MICROSTRUCTURE AND HARDNESS OF FRICTION STIR PROCESSED AZ31 WITH SiCP

2008 ◽  
Vol 22 (18n19) ◽  
pp. 2879-2885 ◽  
Author(s):  
M. NAJAFI ◽  
A. M. NASIRI ◽  
A. H. KOKABI
Keyword(s):  
Grain Size ◽  
Magnesium Alloys ◽  
Base Material ◽  
Ultrafine Grain ◽  
Matrix Composites ◽  
Magnesium Matrix Composites ◽  
Friction Stir ◽  
Sic Particles ◽  
Ultrafine Grain Size ◽  
Potential Weight

Friction stir processing (FSP) is a novel technique to produce ultrafine grained materials. Most of the researches conducted on FSP focus on aluminum alloys. Despite the potential weight reduction that can be achieved by using magnesium alloys, a few researches have been reported on FSP of magnesium alloys. In this work, the possibility of using FSP with and without SiC particles to modify the microstructure and hardness of commercial AZ31 is examined. SiC particles were uniformly dispersed into an AZ31 matrix by FSP. The mean grain size of the stir zone with the SiC particles was obviously smaller than the same zone without the SiC particles. SiC reinforced magnesium matrix composites created by FSP with cooling rapidly the plate that exhibit ultrafine grain size approximately 1μm and nearly doubled the hardness of the base material.

Grain Refinement of Mg-Y-Zn Alloy by Friction Stir Processing

2007 ◽  
Vol 26-28 ◽  
pp. 465-468 ◽  
Author(s):  
Taiki Morishige ◽  
Masato Tsujikawa ◽  
Sachio Oki ◽  
M. Kamita ◽  
Sung Wook Chung ◽  
...  
Keyword(s):  
Grain Size ◽  
Magnesium Alloy ◽  
Grain Refinement ◽  
Friction Stir Processing ◽  
Az31 Alloy ◽  
Frictional Heat ◽  
Light Metals ◽  
Friction Stir ◽  
The Difference ◽  
Zn Alloy

Grain refinement of magnesium alloy by Friction Stir Processing (FSP) was investigated. It is assumed that dynamic recrystallization (DRX) is occurred by frictional heat and plastic flow during FSP. This process is the effective method of the grain refinement for light metals. In this study, FSP was conducted to cast Mg alloys for and the difference of the grain refinement by DRX in these alloys was examined. As a result, in comparison with commercial Mg-Al-Zn alloy and Mg-Y-Zn alloy have finer microstructure. The grain size of FSP-ed Mg-Y-Zn alloy was ~1.7 [/m], however, that of AZ31 alloy was 20~30 [/m].

A Novel Way to Fabricate Carbon Nanotubes Reinforced Copper Matrix Composites by Friction Stir Processing

2011 ◽  
Vol 391-392 ◽  
pp. 524-529 ◽  
Author(s):  
Wen Liang Chen ◽  
Chun Ping Huang ◽  
Li Ming Ke
Keyword(s):  
Carbon Nanotubes ◽  
Grain Size ◽  
Friction Stir Processing ◽  
Copper Matrix ◽  
Parent Material ◽  
Experimental Results ◽  
Matrix Composites ◽  
Small Decrease ◽  
Copper Matrix Composites ◽  
Friction Stir

Carbon nanotubes(CNTs) reinforced copper matrix composites were successfully produced by Friction Stir Processing (FSP). The effect of applying multiple FSP passes on the forming of composites was studied, the microstructure, microhardness and conductivity of the good forming composite were analyzed. The experimental results showed that CNTs uniformly distributed and good forming composite can be obtained by three FSP passes. Compared to the parent material, the grain size of the composite has significantly refined, and the microhardness of the composite has also greatly improved, but the conductivity of the composite has a small decrease.

Friction Stir Processing: An Operational Method to Improve Ductility in Pure Copper

2013 ◽  
Vol 818 ◽  
pp. 14-19 ◽  
Author(s):  
Vahid Rezazadeh ◽  
Ali Sharbatzadeh ◽  
Ali Hosseinzadeh ◽  
Amir Safari ◽  
Salar Salahi
Keyword(s):  
Friction Stir Processing ◽  
Rotational Speed ◽  
Pure Copper ◽  
Traverse Speed ◽  
Ultrafine Grain ◽  
Work Piece ◽  
Cavity Formation ◽  
Nugget Zone ◽  
Friction Stir ◽  
Lower Heat

mproving ductility in metals using friction stir processing (FSP) is a challenging effort and is made by means of a rotating tool inserted in a work piece providing heat transfer and plastic deformation. In this investigation, improving ductility during FSP was determined as a purpose and the microstructure and mechanical properties of nugget zone were investigated during friction stir processing (FSP) of pure copper. Ductility was measured using tensile elongations at a temperature of 20 °C. By varying the traverse speed from 40 to 100 mm/min at rotation speeds of 300 and 600 rpm, the ultrafine grain microstructure was achieved .Defects were observed in rotational speed of 300 rpm. By increasing traverse speed at constant rotational speed of 600 rpm grain size of the nugget zone decreased and ductility increased. Achievable ductility was limited by cavity formation due to lower heat input and deformation in samples with defects.

The Effects of Free Space in Mould Cavity on Sandglass Extrusion

2005 ◽  
Vol 475-479 ◽  
pp. 2999-3002
Author(s):  
W.L. Lu ◽  
Y. Wang ◽  
Jin Tao Hai
Keyword(s):  
Grain Size ◽  
Free Space ◽  
Large Strain ◽  
Experimental Results ◽  
Experimental Result ◽  
Ultrafine Grain ◽  
Theory Analysis ◽  
Ultrafine Grain Size ◽  
Mould Cavity

Sandglass extrusion is an ultrafine grain size method. Due to the repetitive and multiple extrusions, large strain will be accumulated and ultafine grain size can be obtained. There are some factors that can affect the experimental result of sandglass extrusion. Among these factors, free space in mould cavity is very important, which can affect the forming of the fold during the extrusion. In this paper, the effects of free space in mould cavity on sandglass extrusion have been discussed and theory analysis and experimental results have been reported.

Pre-cooling Effects on the Resulting Grain Size in Friction Stir Processing of AZ31B

2015 ◽  
pp. 355-365
Author(s):  
Ali H. Ammouri ◽  
Ghassan T. Kridli ◽  
George Y. Ayoub ◽  
Ramsey F. Hamade
Keyword(s):  
Grain Size ◽  
Friction Stir Processing ◽  
Friction Stir ◽  
Cooling Effects

scholarly journals Effect of Friction Stir Processing on Gas Tungsten Arc-Welded and Friction Stir-Welded 5083-H111 Aluminium Alloy Joints

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Sipokazi Mabuwa ◽  
Velaphi Msomi
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Aluminium Alloy ◽  
Friction Stir Processing ◽  
Welded Joints ◽  
Ultrafine Grain ◽  
Dimple Size ◽  
Friction Stir ◽  
Gas Tungsten Arc ◽  
Gas Tungsten

This paper presents the analysis of the friction stir-processed aluminium alloy 5083-H111 gas tungsten arc-welded and friction stir-welded joints. The comparative analysis was performed on the processed and unprocessed gas tungsten arc-welded and friction stir-welded joints of similar aluminium alloy 5083-H111. The results showed a clear distinction between the friction stir processed joints and unprocessed joints. There is a good correlation observed between the microstructural results and the tensile results. Ultrafine grain sizes of 4.62 μm and 7.177 μm were observed on the microstructure of the friction stir-processed friction stir-welded and gas tungsten arc-welded joints. The ultimate tensile strength for friction stir-welded and gas tungsten arc-welded before friction stir processing was 153.75 and 262.083 MPa, respectively. The ultimate tensile strength for friction stir processed friction stir-welded joint was 303.153 MPa and gas tungsten arc-welded joints one was 249.917 MPa. The microhardness values for the unprocessed friction stir-welded and gas tungsten arc-welded joints were both approximately 87 HV, while those of the friction stir-processed ones were 86.5 and 86 HV, respectively. The application of friction stir processing transformed the gas tungsten arc morphology from brittle to ductile dimples and reduced the ductile dimple size of the unprocessed friction stir-welded joints from the range of 4.90–38.33 μm to 3.35–15.59 μm.

scholarly journals Friction Stir Processing of the Magnesium Alloy AZ61: Grain Size Refinement and Mechanical Properties

2012 ◽  
Vol 706-709 ◽  
pp. 1823-1828 ◽  
Author(s):  
J.A. del Valle ◽  
P. Rey ◽  
D. Gesto ◽  
D. Verdera ◽  
Oscar A. Ruano
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Magnesium Alloy ◽  
Friction Stir Processing ◽  
Superplastic Forming ◽  
Important Change ◽  
Heat Extraction ◽  
Processing Temperature ◽  
Friction Stir ◽  
Size Refinement

The effect of friction stir processing (FSP), on the microstructure and mechanical properties of a magnesium alloy AZ61 has been analyzed. This is a widely used wrought magnesium alloy provided in the form of rolled and annealed sheets with a grain size of 45 μm. The FSP was performed with an adequate cooling device in order to increase the heat extraction and reduce the processing temperature. The final microstructure showed a noticeable grain size refinement down to values close to 1.8 μm and an important change in texture. The change in texture favors basal slip during tensile testing leading to an increase of ductility and a decrease in yield stress. The stability of the grain size and the creep behavior at high temperatures were investigated. The optimum conditions for superplastic forming were determined; however, the presence of a large amount of cavities precludes the achievement of high superplastic elongations. Additionally, these results are compared with those obtained by severe hot rolling.

PRODUCING NANOCOMPOSITE LAYER ON THE SURFACE OF AS-CAST AZ91 MAGNESIUM ALLOY BY FRICTION STIR PROCESSING

2012 ◽  
Vol 05 ◽  
pp. 375-382
Author(s):  
P. ASADI ◽  
M. K. BESHARATI GIVI ◽  
G. FARAJI
Keyword(s):  
Grain Size ◽  
Magnesium Alloy ◽  
Friction Stir Processing ◽  
Composite Layer ◽  
Az91 Magnesium Alloy ◽  
Friction Stir ◽  
Nanocomposite Layer ◽  
Sic Particles ◽  
Developed Surface ◽  
Mechanical And Microstructural Properties

Friction stir processing (FSP) is an effective tool to produce a surface composite layer with enhanced mechanical properties and modified microstructure of as-cast and sheet metals. In the present work, the mechanical and microstructural properties of as-cast AZ 91 magnesium alloy were enhanced by FSP and an AZ 91/ SiC surface nanocomposite layer has been produced using 30 nm SiC particles. Effect of the FSP pass number on the microstructure, grain size, microhardness, and powder distributing pattern of the surface developed has been investigated. The developed surface nanocomposite layer presents a higher hardness, an ultra fine grain size and a better homogeneity. Results show that, increasing the number of FSP passes enhances distribution of nano-sized SiC particles in the AZ 91 matrix, decreases the grain size, and increases the hardness significantly. Also, changing of the tool rotating direction results much uniform distribution of the SiC particles, finer grains, and a little higher hardness.

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