Ultrafine Grain Structure Development in Aluminium Alloy by Strain Hardening using CCGP

2021 ◽  
Vol 1 (2) ◽  
pp. 25-31
Author(s):  
HS Siddesha ◽  
Suhaaskapardhi BS ◽  
Goutham C
Keyword(s):  
Tensile Strength ◽  
Aluminium Alloy ◽  
Research Work ◽  
Industrial Applications ◽  
Grain Structure ◽  
Ultrafine Grain ◽  
Fine Grained ◽  
Processed Material ◽  
Super Plastic ◽  
Ultrafine Grain Structure

Severe Plastic Deformation (SPD) processes are for developing ultrafine grained (UFG) structured materials for different Industrial applications. Cyclic Constrained Groove Pressing (CCGP) is a technique, produce fine grained structures in metallic sheets or plates in mass production. The objective of research work is to investigate the influence of CCGP processing on the super plastic behaviour of an Aluminium alloy. Samples in “ascast” materials processed by CCGP with as cast, 1, 2, 3 and 4 passes. Processed Material study for microhardness and Tensile strength mechanical properties test were done for different test specimens. Grain refinement, microhardness and Tensile strength increased with the number of CCGP passes.

Ultrafine Grain Structure Evolution in AA6085 Aluminium Alloy Processed by HPT at Increased Temperature

2012 ◽  
Vol 706-709 ◽  
pp. 1864-1869
Author(s):  
Jozef Zrník ◽  
Libor Kraus ◽  
Stephan Scheriau ◽  
Reinhard Pippan
Keyword(s):  
Thermal Treatment ◽  
Aluminium Alloy ◽  
Strain Level ◽  
Grain Structure ◽  
Structure Evolution ◽  
Ultrafine Grain ◽  
Initial Structure ◽  
Increased Temperature ◽  
Ultrafine Grain Structure ◽  
The Impact

In this study ultrafine grain structure evolution during high pressure torsion (HPT) of commercial aluminium alloy AA6082 at increased temperature is presented. Two different initial structural states of the alloy were prepared by thermal treatment. The progress in structure refinement in dependence on the shear strain level strain was investigated by TEM of thin foils. The impact of different amount of strain (εef) introduced was analyzed with respect to the effect of increased temperature. The microhardness results measured across the deformed discs pointed out that some data scattering. The results of microstructure analyses showed that ultrafine grain (ufg) structure was already formed in deformed disc upon the first turn, regardless the initial structure of alloy, resulting from prior thermal treatment. The observed heterogeneity in ufg structure formation across the deformed disc was observed, supporting microhardness results scattering. By increasing the strain level (number of turns N-2,4,6), more effectively homogenized ufg structure was observed across the deformed discs. The effect of increased deformation temperature became evident and dynamic recrystalization modified locally ufg structure.. The retardation of new grains growth and higher thermal stability of ufg structure was observed, when two steps thermal treatment of alloy (quenching and ageing) was executed prior deformation. Strength measurements results yielded form tensile tests showed that the effect of structure strengthening was degraded by local recrystallization. The results of torque measurement versus the time showed that the torque required to deform the sample was increasing until the first turn and then kept stable or even decreased.

Grain Refinement and Deformation Behavior of Ultrafine Grained Pd and Pd-Ag Alloys Produced by HPT

2008 ◽  
Vol 584-586 ◽  
pp. 182-187
Author(s):  
Lilia Kurmanaeva ◽  
Yulia Ivanisenko ◽  
J. Markmann ◽  
Ruslan Valiev ◽  
Hans Jorg Fecht
Keyword(s):  
Mechanical Properties ◽  
Deformation Behavior ◽  
Materials Science ◽  
High Pressure Torsion ◽  
Uniform Elongation ◽  
Grain Structure ◽  
Coarse Grained ◽  
Ultrafine Grain ◽  
Ultrafine Grained ◽  
Ultrafine Grain Structure

Investigations of mechanical properties of nanocrystalline (nc) materials are still in interest of materials science, because they offer wide application as structural materials thanks to their outstanding mechanical properties. NC materials demonstrate superior hardness and strength as compared with their coarse grained counterparts, but very often they possess a limited ductility or show low uniform elongation due to poor strain hardening ability. Here, we present the results of investigation of the microstructure and mechanical properties of nc Pd and Pd-x%Ag (x=20, 60) alloys. The initially coarse grained Pd-x% Ag samples were processed by high pressure torsion, which resulted in formation of homogenous ultrafine grain structure. The increase of Ag contents led to the decrease of the resulted grain size and change in deformation behavior, because of decreasing of stacking fault energy (SFE). The samples with larger Ag contents demonstrated the higher values of hardness, yield stress and ultimate stress. Remarkably the uniform elongation had also increased with increase of strength.

Grain Refinement of an Al-Cu-Mg Alloy by Microalloying and Common Thermo-Mechanical Treatment

2007 ◽  
Vol 546-549 ◽  
pp. 917-922
Author(s):  
Bao Lin Wu ◽  
Gui Ying Sha ◽  
Yi Nong Wang ◽  
Yu Dong Zhang ◽  
Claude Esling
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Mechanical Treatment ◽  
Grain Structure ◽  
Mg Alloy ◽  
Ultrafine Grain ◽  
Fine Grain ◽  
Thermo Mechanical Treatment ◽  
Ultrafine Grain Structure ◽  
Thermal Stability Of

Heavy deformation plus micro alloying could be an effective way to obtain ultrafine grain structure of metals. In the present work, an Al-Cu-Mg alloy was microalloyed with Zr to obtain homogeneous precipitates and then heavily deformed by conventional forging at high temperature. The possible refining processing routes were studied and the superplasticity behaviors of the alloy was investigated. Results show that the micro alloyed alloy can be stably refined to 3-5μm under conventional processing routes. The Al-3Zr precipitates act both as additional sites to enhance recrystallization nucleation rate and pins to impede grain growth to increase the thermal stability of the fine grain structure. However, as the Al3Zr precipitates remains along grain boundaries, the superplastic capability of the material is not high. At 430°C with 1×10-4S-1 strain rate, the elongation obtained was 260%.

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 The Production of Material with Ultrafine Grain Structure in Al-Zn Alloy in the Process of Rapid Solidification

2014 ◽  
Vol 14 (2) ◽  
pp. 57-62
Author(s):  
M. Szymaneka ◽  
B. Augustyn ◽  
D. Kapinos ◽  
S. Boczkal ◽  
J. Nowak
Keyword(s):  
Rapid Solidification ◽  
Melt Spinning ◽  
Hot Extrusion ◽  
High Strength ◽  
Strength Properties ◽  
Grain Structure ◽  
Ultrafine Grain ◽  
Plastic Working ◽  
Metal Treatment ◽  
Ultrafine Grain Structure

Abstract In the aluminium alloy family, Al-Zn materials with non-standard chemical composition containing Mg and Cu are a new group of alloys, mainly owing to their high strength properties. Proper choice of alloying elements, and of the method of molten metal treatment and casting enable further shaping of the properties. One of the modern methods to produce materials with submicron structure is a method of Rapid Solidification. The ribbon cast in a melt spinning device is an intermediate product for further plastic working. Using the technique of Rapid Solidification it is not possible to directly produce a solid structural material of the required shape and length. Therefore, the ribbon of an ultrafine grain or nanometric structure must be subjected to the operations of fragmentation, compaction, consolidation and hot extrusion. In this article the authors focussed their attention on the technological aspect of the above mentioned process and described successive stages of the fabrication of an AlZn9Mg2.5Cu1.8 alloy of ultrafine grain structure designated for further plastic working, which enables making extruded rods or elements shaped by the die forging technology. Studies described in the article were performed under variable parameters determined experimentally in the course of the alloy manufacturing process, including casting by RS and subsequent fragmentation.

Ultrafine-grain structure and properties of carbon-steel wire after complex deformation

2014 ◽  
Vol 44 (5) ◽  
pp. 390-393 ◽  
Author(s):  
M. A. Polyakova ◽  
A. E. Gulin ◽  
O. A. Nikitenko ◽  
D. V. Konstantinov ◽  
M. S. Zherebtsov
Keyword(s):  
Carbon Steel ◽  
Steel Wire ◽  
Grain Structure ◽  
Ultrafine Grain ◽  
Structure And Properties ◽  
Complex Deformation ◽  
Ultrafine Grain Structure

Effect of Heat Treatment on the Mechanical Properties of Wrought Al-Zn-Mg-Cu Alloy Cast by Rapid Solidification

2013 ◽  
Vol 765 ◽  
pp. 496-500 ◽  
Author(s):  
Dawid Kapinos ◽  
Marcin Szymanek ◽  
Bogusław Augustyn ◽  
Maciej Gawlik
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Rapid Solidification ◽  
Solution Heat Treatment ◽  
Grain Structure ◽  
Ultrafine Grain ◽  
Cu Alloy ◽  
Optimum Heat ◽  
Ultrafine Grain Structure ◽  
Alloy Cast

The article presents the change in mechanical properties of AlZn9Mg2.5Cu1.8 alloy resulting from the process of solution heat treatment and aging. The heat treatment was performed on a unique UMSA (Universal Metallurgical Simulator and Analyzer) device. The aim of the study was to determine optimum heat treatment parameters for the tested alloy of ultrafine grain structure obtained by Rapid Solidification (RS). To achieve this purpose, heat treatment to the T4 and T6 condition was carried out. The solution heat treatment was carried out at a constant temperature of 460 °C for 2 hours, while the time - temperature parameters of the aging process varied. The treatment undertaken resulted in improved mechanical properties.

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