Effect of Distance between Passes in Friction Stir Processing of Magnesium Alloy

2012 ◽  
Vol 585 ◽  
pp. 397-401 ◽  
Author(s):  
M. Govindaraju ◽  
K. Rao Prasad ◽  
Uday Chakkingal ◽  
K. Balasubramanian
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Friction Stir Processing ◽  
Developmental Studies ◽  
Secondary Phases ◽  
Friction Stir ◽  
Processed Material ◽  
The Matrix ◽  
Cast Alloys ◽  
Tool Pin

Friction stir processing is applied for property improvement of cast alloys for last two decades and many developmental studies were carried out in this topic on various alloys. In the current work, friction stir processing was carried out on rare earth containing magnesium alloy AE42. This alloy was specially developed for automobile application as it has better creep resistance than commercial magnesium alloys. Multi-pass Friction Stir Processing was carried out with varying the distance between passes from 0.5 mm to 2.5 mm using 12 mm shoulder diameter tool. Pin was with conical (tapered) and flat configurations with 3 mm height. After processing, the resultant mechanical and metallurgical properties were evaluated. Microstructure was refined to 5 micron and the secondary phases were made in to tiny pieces of 0.5-1 micron and evenly distributed in the matrix. Continuous network of grain boundary which is reason for poor mechanical properties was eliminated. Mechanical properties were improved by 30%. The variation of mechanical properties of processed material with respect to variation of distance between passes was negligible from 1 mm to 1.5 mm for flat pin tool.

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.

Enhancing the Mechanical Properties of AE42 Magnesium Alloy through Friction Stir Processing

2013 ◽  
Vol 16 (5) ◽  
pp. 571-580 ◽  
Author(s):  
Harpreet Singh Arora ◽  
Harpreet Singh Grewal ◽  
Harpreet Singh ◽  
Brij Kumar Dhindaw ◽  
Sundeep Mukherjee
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Friction Stir Processing ◽  
Friction Stir

Fabrication of metal-matrix AL7075T651/TiN nano composite employing friction stir process

2015 ◽  
Vol 231 (8) ◽  
pp. 1319-1331 ◽  
Author(s):  
Khalid A Al-Ghamdi ◽  
G Hussain ◽  
R Hashemi
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Processing ◽  
Mechanical Tests ◽  
Processing Route ◽  
Tool Geometry ◽  
Nano Composite ◽  
Friction Stir ◽  
Tool Pin ◽  
Number Of Passes ◽  
Tool Rotation

Friction stir processing is a novel material fabrication technique. This study was undertaken in order to investigate a suitable set of friction stir processing parameters to form AL7075T651/TiN nano composite. A number of samples were produced by varying the process parameters, namely, tool-pin geometry, number of passes and the direction of tool rotation. The pin geometries employed include triangular, square and threaded taper; the passes were varied over two levels (i.e. 2 and 4) and the tool rotation was changed as clockwise and counter clockwise between the successive passes. The effect of these variations on the composite was quantified through several microstructural and mechanical tests. The increase in the number of passes was observed to improve various characteristics of the composite (i.e. distribution of TiN particles, grain refinement and mechanical properties). The effect of tool geometry, however, was associated with the choice of the number of passes. The change in the direction of tool rotation between the consecutive passes was witnessed to improve the distribution of TiN particles. From the X-ray diffraction analysis of the samples, the formation of several new phases was detected. These were found to have effect on the mechanical properties of the composite. A good trade-off among various properties of the composite (i.e. hardness, tensile strength and ductility) was realized when the friction stir processing was performed using square tool and employing four passes with simultaneously changing the direction of tool rotation between the successive passes. This study is the first report on the fabrication of AL7075T651/TiN nano composite through friction stir processing route.

Numerical and Experimental Investigation on Hot Backward Extrusion Process of Mg-Gd-Y-Zn-Zr Magnesium Alloy

2014 ◽  
Vol 788 ◽  
pp. 127-133 ◽  
Author(s):  
Zhi Wen Shao ◽  
Xiu Rong Zhu ◽  
Jun Wang ◽  
Rong Wang ◽  
Yong Dong Xu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Hot Extrusion ◽  
Element Model ◽  
Extrusion Process ◽  
Tensile Yield Strength ◽  
Secondary Phases ◽  
Rigid Plastic ◽  
Backward Extrusion ◽  
The Matrix

The hot backward extrusion process of the Mg-Gd-Y-Zn-Zr magnesium alloy was investigated by both numerical simulation and experiments. An axisymmetric 2D rigid-plastic finite element model (FEM) was established to simulate the material flow during the extrusion process. The shapes of the dies were optimized in order to avoid severe stress concentration and obtain uniform deformation of the workpiece. After hot extrusion, the microstructures of the alloys were obviously refined, and the secondary phases which included many long-period stacking order (LPSO) phases precipitated in the matrix. The optimal comprehensive mechanical properties of the alloy have been obtained after extrusion and ageing at 200°C for 48h with the ultimate tensile strength of 434MPa, tensile yield strength of 375MPa and elongation of 4.5%, respectively. The good mechanical properties were mainly attributed to the fine microstructures and numerous precipitates in the matrix.

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