Influence of cooling media in achieving grain refinement of AA2014 alloy using friction stir processing

2020 ◽  
Vol 234 (22) ◽  
pp. 4520-4534
Author(s):  
MVNV Satyanarayana ◽  
Adepu Kumar
Keyword(s):  
Grain Boundaries ◽  
Friction Stir Processing ◽  
Heat Dissipation ◽  
Electron Backscattered Diffraction ◽  
Friction Stir ◽  
Fine Grained ◽  
Fine Grained Structure ◽  
Cooling Media ◽  
Processing Zone ◽  
Friction Stir Processing Sample

The present paper studies the influence of different cooling media (water and cryogenic media) on microstructure, mechanical, and corrosion behavior of friction stir processing of AA2014. From the electron backscattered diffraction results, it was observed that the grain size in stir zone of air-cooled friction stir processing, dry ice-cooled friction stir processing, and underwater friction stir processing are 4.9 µm, 3.5 µm, and 0.9 µm respectively, and the fraction of high angle grain boundaries are more in underwater friction stir processing sample compared to other conditions. The ultra-fine grained structure (0.9 µm) was achieved in underwater friction stir processing due to uniform heat dissipation from the processing zone to the water. Mechanical properties such as hardness and strength were improved in underwater friction stir processing compared to other conditions. The fine precipitates formed in the underwater friction stir processing sample were distributed randomly at grain boundaries, and hence corrosion resistance was improved in underwater friction stir processing sample compared to other conditions.

Microstructure Development in Single and Double-Pass Friction Stir Processing of Aluminium

2013 ◽  
Vol 753 ◽  
pp. 50-53 ◽  
Author(s):  
Devinder Yadav ◽  
Ranjit Bauri
Keyword(s):  
Grain Size ◽  
Grain Boundaries ◽  
Friction Stir Processing ◽  
Recrystallization Process ◽  
Pure Aluminium ◽  
Electron Backscattered Diffraction ◽  
Double Pass ◽  
Tem Analysis ◽  
Friction Stir ◽  
First Pass

Single pass and double-pass friction stir processing was carried out on commercially pure aluminium at a rotation speed of 640 rpm and traverse speed of 150 mm/min and a detailed electron backscattered diffraction (EBSD) and transmission electron microscopy (TEM) analysis was carried out to understand the microstructure developed. The grain size was refined substantially after the first pass whereas there was no significant change in the grain size after the second pass. This indicates that the final grain size after friction stir processing does not depend on the starting grain size. The equiaxed fine grains were formed by dynamic recrystallization process as revealed by EBSD analysis. TEM observations showed banded contrast across the grain boundaries indicating grain boundaries to be in equilibrium. Free dislocations observed inside grains after the first pass were well arranged into subgrain boundaries after the second pass. EBSD also revealed some variation in microstructural features such as grain size, texture index, grain orientation spread and grain average misorientation across the surface and also in the cross section of the stir zone both after single and double pass.

scholarly journals ALUMINUM BASED COMPOSITES OBTAINED BY FSP (REVIEW)

2021 ◽  
Vol 3 ◽  
pp. 148-153
Author(s):  
Christo Kondoff ◽  
Radostina Zaekova ◽  
Marina Manilova
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloys ◽  
Friction Stir Processing ◽  
Performance Characteristics ◽  
Plastic State ◽  
Aluminum Composites ◽  
Friction Stir ◽  
Fine Grained ◽  
Fine Grained Structure ◽  
Basic Parameters

The composites based on aluminum alloys obtained by friction stir processing (FSP) combine the advantages of lightweight aluminum composites with the well-refined structure obtained by deformation in plastic state. When reinforcing elements in the form of powders or nanoplates are introduced in the process, of mixing they are evenly distributed in the processes zone, which acquires a fine-grained structure. The study examines specific results in the use of various tools and materials, as well as some basic parameters of the process in terms of surface smoothness, defects and some performance characteristics of the tested samples, such as strength, ductility, hardness and corrosion resistance.  

Influence of Texture Evolution on Mechanical and Damping Properties of SiC/Li2ZrO3/Al Composite Through Friction Stir Processing

2019 ◽  
Vol 142 (2) ◽  
Author(s):  
Subhash Singh ◽  
Kaushik Pal
Keyword(s):  
Cross Sections ◽  
Friction Stir Processing ◽  
Texture Evolution ◽  
Deep Understanding ◽  
Matrix Composites ◽  
Damping Properties ◽  
Electron Backscattered Diffraction ◽  
Friction Stir ◽  
Lithium Zirconate ◽  
Al Composite

Abstract In this study, parent aluminum (Al), silicon carbide (SiC) reinforced Al, zirconia (ZrO2) coated SiC reinforced Al, and lithium zirconate spinel (Li2ZrO3, LZO) encapsulated SiC incorporated Al metal matrix composites were processed via friction stir processing (FSP) technique to observe the influence of grain refinement on mechanical and damping properties. Electron backscattered diffraction (EBSD) analysis were conducted for detailed and deep understanding of possible mechanism and microstructure at longitudinal cross sections of the samples. Further, the room temperature mechanical properties and thermal cyclic (−100 to 400 °C) damping performance of the friction stir processed composites were studied. The results obtained in this investigation show that storage modulus of pristine Al, SiC reinforced Al, ZrO2 coated SiC reinforced Al, and LZO coated SiC reinforced Al were improved by a factor of 1.09, 1.17, 1.09, and 1.38, respectively, after FSP. Additionally, the ultimate tensile strength (UTS) and hardness of the friction stir processed SiC/Li2ZrO3/Al composite were improved by a factor of 1.08 and 1.11, respectively, after FSP was compared with an unprocessed composite.

Machining characteristics of fine grained AZ91 Mg alloy processed by friction stir processing

2017 ◽  
Vol 27 (4) ◽  
pp. 804-811 ◽  
Author(s):  
G.V.V. SURYA KIRAN ◽  
K. HARI KRISHNA ◽  
Sk. SAMEER ◽  
M. BHARGAVI ◽  
B. SANTOSH KUMAR ◽  
...  
Keyword(s):  
Friction Stir Processing ◽  
Mg Alloy ◽  
Friction Stir ◽  
Fine Grained ◽  
Machining Characteristics

scholarly journals Texture Evolution in Biocompatible Mg-Y-Re Alloy After Friction Stir Processing

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1181 ◽  
Author(s):  
Kunčická ◽  
Král ◽  
Dvořák ◽  
Kocich
Keyword(s):  
Grain Boundaries ◽  
Friction Stir Processing ◽  
Texture Evolution ◽  
Secondary Recrystallization ◽  
Positive Influence ◽  
Fiber Texture ◽  
Ultimate Tensile Stress ◽  
Friction Stir ◽  
Grain Sizes ◽  
Sample Average

The presented study deals with the investigation of biocompatible WE 43 Mg-based alloy processed via the combination of rotary swaging (RS) and friction stir processing (FSP) at three different rotational speeds of 400 RPM, 800 RPM, and 1200 RPM. The structure observations primarily focused on texture development and characterizations of grain sizes and grain boundaries. The results showed that swaging plus processing at 400 RPM and 1200 RPM lead to substantial recrystallization and grain refinement. The fractions of low angle grain boundaries within the 400 RPM and 1200 RPM samples were approximately 11%, while for the 800 RPM sample exhibiting secondary recrystallization it was about 22%. The grains were also the finest in the 1200 RPM sample (average grain diameter of 1.8 µm). The processed structures exhibited a slight tendency to form the {10-10} <0001> preferential fiber texture (especially the 800 RPM sample). Tensile testing showed the FSP to have positive influence on the ultimate tensile stress, as well as ductility of all the samples; the mechanical properties improved with increasing FSP rate.

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