Recrystallization of ECAP-Processed AA4343 Aluminium Alloy Containing Large Second Phase Particles

2013 ◽  
Vol 753 ◽  
pp. 239-242
Author(s):  
Henryk Paul ◽  
Thierry Baudin ◽  
François Brisset ◽  
Anna Tarasek
Keyword(s):  
High Resolution ◽  
Aluminium Alloy ◽  
Second Phase ◽  
Pure Aluminium ◽  
Microstructure Development ◽  
Commercial Purity ◽  
Ecap Processing ◽  
Pure Silicon ◽  
Second Phase Particles ◽  
Deformed State

The objective of this study was to determine the effect of ECAP-processing on the texture and the microstructure development of the deformed and recrystallized material. The commercial purity AA4343 aluminium alloy, containing very large second phase particles (SPP) of pure silicon, was deformed via route C up to 10 passes and then annealed. The samples were characterized by TEM and SEM equipped with high resolution EBSD. It was found that the microstructure of the deformed state in areas far from coarse SPP was very similar to that observed in pure aluminium. The orientations of the new grains were scattered but not random and only specific groups of orientations were observed.

Mechanical and Corrosion Behavior of Pure Aluminium Added Friction Stir Weld Joint of Aluminium Alloy

2019 ◽  
Vol 821 ◽  
pp. 327-333
Author(s):  
Sunil Sinhmar ◽  
Dheerendra Kumar Dwivedi
Keyword(s):  
Friction Stir Welding ◽  
Aluminium Alloy ◽  
Corrosion Behavior ◽  
Weld Joint ◽  
Second Phase ◽  
Pure Aluminium ◽  
Nugget Zone ◽  
Friction Stir ◽  
Aluminium Addition ◽  
Aluminium Strip

Friction stir welding (FSW) of AA2014 aluminium alloy was performed by sandwiching pure aluminium (Al) in the form of strip between the abutting surfaces. Mechanical and corrosion behavior of weld joint with and without pure aluminium addition was compared. Friction stir welding was carried out at rotational speed of 931 rpm and traverse speed of 41 mm/min. Pure aluminium strip of 1 mm thickness was used for incorporating Al in weld nugget zone. Microstructure analysis was carried out using optical microscope and FESEM with energy dispersive spectroscopy (EDS). Microhardness and tensile testing were performed on the weld joints. Corrosion behavior was investigated using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (Tafel) test. FESEM analysis was performed before and after corrosion test. Traces of pure aluminium strip were observed in the microstructure. The incorporated strip was found not to be uniformly distributed in the nugget zone. Pure aluminium addition reduced the extent of formation of the second phase particle in the nugget zone as compared to the normal FSW joint i.e. without Al addition. This metallurgical homogeneity resulted in better corrosion resistance of the Al added weld joint than the normal FSW joint.

scholarly journals Alloying and Processing Effects on the Microstructure, Mechanical Properties, and Degradation Behavior of Extruded Magnesium Alloys Containing Calcium, Cerium, or Silver

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 391 ◽  
Author(s):  
Jan Bohlen ◽  
Sebastian Meyer ◽  
Björn Wiese ◽  
Bérengère J. C. Luthringer-Feyerabend ◽  
Regine Willumeit-Römer ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloys ◽  
Processing Parameters ◽  
Second Phase ◽  
Degradation Behavior ◽  
Microstructure Development ◽  
Corrosion Properties ◽  
Second Phase Particles ◽  
Degradation Rates ◽  
The Relationship

Magnesium alloys attract attention as degradable implant materials due to their adjustable corrosion properties and biocompatibility. In the last few decades, especially wrought magnesium alloys with enhanced mechanical properties have been developed, with the main aim of increasing ductility and formability. Alloying and processing studies allowed demonstrating the relationship between the processing and the microstructure development for many new magnesium alloys. Based on this experience, magnesium alloy compositions need adjustment to elements improving mechanical properties while being suitable for biomaterial applications. In this work, magnesium alloys from two Mg-Zn series with Ce (ZE) or Ca (ZX) as additional elements and a series of alloys with Ag and Ca (QX) as alloying elements are suggested. The microstructure development was studied after the extrusion of round bars with varied processing parameters and was related to the mechanical properties and the degradation behavior of the alloys. Grain refinement and texture weakening mechanisms could be improved based on the alloy composition for enhancing the mechanical properties. Degradation rates largely depended on the nature of second phase particles rather than on the grain size, but remained suitable for biological applications. Furthermore, all alloy compositions exhibited promising cytocompatibility.

Crystallographic Aspects of Deformation and Recrystallization in ECAP-Processed AA3104 Aluminium Alloy

2012 ◽  
Vol 186 ◽  
pp. 98-103
Author(s):  
Henryk Paul ◽  
Thierry Baudin ◽  
Anna Tarasek ◽  
François Brisset
Keyword(s):  
Aluminum Alloy ◽  
Shear Bands ◽  
Microstructure Development ◽  
Commercial Purity ◽  
Local Orientation ◽  
Ecap Processing ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Equiaxed Grains ◽  
Scanning Electron

The objective of this study was to determine the effect of ECAP-processing on the texture and the microstructure development of the deformed and recrystallized states. The commercial purity AA3104 aluminum alloy was deformed via route A up to 7 passes and then annealed to obtain the state of partial recrystallization. The shear bands formation and the texture transformation in annealing were investigated with the use of high resolution transmission and scanning electron microscopes equipped with the facilitates for the local orientation measurements. It was found that the instability of the layered structure of the flat grains within some narrow areas led to the formation of the kink-type bands, which were precursors of the shear bands. The orientations of the new grains occurring in the recrystallized samples were not random, i.e. only specific groups of orientations were observed. In most of the observed cases, the growth of the recrystallized grains led to nearly homogeneous equiaxed grains of a similar size.

Effect of Second Phase Particles on the Tensile Instability of a Nanostructured Al-1%Si Alloy

2014 ◽  
Vol 783-786 ◽  
pp. 2629-2634 ◽  
Author(s):  
Tian Lin Huang ◽  
Gui Lin Wu ◽  
Qing Liu ◽  
Xiao Xu Huang
Keyword(s):  
Tensile Tests ◽  
Structural Features ◽  
Second Phase ◽  
Commercial Purity ◽  
Localized Deformation ◽  
Dispersed Particles ◽  
Transmission Electron ◽  
Second Phase Particles ◽  
Tensile Instability ◽  
Recovery Annealing

A nanostructured Al-1%Si alloy containing dispersed Si particles was produced by heavily cold-rolling to study the effect of second phase particles on the tensile instability of nanostructured metals. Tensile tests were conducted on the as-deformed sample and the samples after recovery annealing treatments. The structural features of deformed and annealed samples were characterized by transmission electron microscopy. By comparing with the behavior of nanostructured commercial purity Al without dispersed particles, a remarked improvement in the tensile stability was found. This is related to a prevention of localized deformation by the presence of finely dispersed Si particles in the nanoscale matrix structure.

High-resolution TEM and analytical study of second-phase particles in Al2O3

1983 ◽  
Vol 41 ◽  
pp. 46-47
Author(s):  
K. J. Morrissey ◽  
Y. Kouh ◽  
C. B. Carter
Keyword(s):  
Grain Size ◽  
High Resolution ◽  
Grain Boundaries ◽  
Hot Pressing ◽  
Analytical Study ◽  
Second Phase ◽  
Initial Powder ◽  
Compact Density ◽  
Second Phase Particles ◽  
High Resolution Tem

The influence of additives such as MgO, NiO, and ZrO2 and impurities such as Na, K, and Ca on the sintering of alumina compacts has been the focus of a considerable amount of research. Since these additives affect compact density and grain size it is of interest to determine the behavior of the elements during processing. That is, it is important to know whether Ca and Mg segregate to grain boundaries or are located in the second-phase particles. Current results suggest that Ca is found uniformly at the grain boundaries and that Mg is accommodated in the second-phase particles.The present investigation is concerned with identifying second-phase particles in different commercially-produced Al2O3 compacts and studying both their structure and composition. Preliminary results have been discussed previously. The investigation has dealt mainly with two different alumina compacts. One compact was prepared from an initial powder containing 0.25% MgO, a small amount of intentionally added Ni, and was prepared by hot pressing.

Effect of Zn, Mg, Cu, Zr on Microstructure and Properties of Laser Welding Aluminium Alloy

2016 ◽  
Vol 877 ◽  
pp. 593-600 ◽  
Author(s):  
Zhi Hao Zhao ◽  
Wen Qiang Liu ◽  
Kai Tao ◽  
Qi Chao Chen ◽  
Gao Song Wang
Keyword(s):  
Laser Welding ◽  
Aluminium Alloy ◽  
Extrusion Direction ◽  
Optical Microscope ◽  
Second Phase ◽  
Ingot Metallurgy ◽  
Extrusion Processing ◽  
Second Phase Particles ◽  
Metallurgical Structure ◽  
Scanning Electron

A series of Al-6.3Zn-2.3Mg-2.3Cu-0.15Zr alloys with different reduce of Zn, Mg, Cu and Zr were prepared by ingot-metallurgy processing. The metallurgical structure and mechanical properties were investigated by optical microscope, scanning electron microscopy and other equipment. The results indicated that the ingot’s microstructures of the four alloys contain the phrases of η (MgZn2) and θ (Al2Cu), which mostly distribute at the grain boundaries in a shape of continuous network. After extrusion processing, the grain of laser welding aluminium alloy was elongated along the extrusion direction, therefore forming fibrous structures, and meanwhile the second phase particles with different degrees of fragmentation were arranged along the extrusion direction since the microstructure of extruded bars was inherited by the as-cast structure. Zr could significantly inhibit recrystallization of alloy; the recrystallization of the alloy with lower Zr was more obvious. As the content of Zr reduced, the tensile strength of alloy decreased, but the electrical conductivity and hardness increased. When the content of Cu was lower, the hardness were decreased.

A Microstructural Study of Reaction-Bonded Silicon Carbide

1992 ◽  
Vol 295 ◽  
Author(s):  
K. Das Chowdhury ◽  
R. W. Carpenter ◽  
W. Braue
Keyword(s):  
Electron Microscopy ◽  
Silicon Carbide ◽  
High Resolution ◽  
High Resolution Electron Microscopy ◽  
Second Phase ◽  
Oxygen Impurity ◽  
Microstructural Study ◽  
Impurity Segregation ◽  
Resolution Electron ◽  
Second Phase Particles

AbstractInterfaces in Reaction Bonded Silicon Carbide (RBSC) have been characterized by Analytical and High Resolution Electron Microscopy. Both Si/SiC and SiC/SiC interfaces were free of any oxygen impurity segregation, but contained metallic impurity precipitates. Oxygen was detected in the second phase particles in the SiC grains. A model is presented to explain the evolution of these second phase particles in the SiC grains.

Research On Method of Discovering Second Phase Particles with Scanning Electron Microscope

2011 ◽  
Vol 287-290 ◽  
pp. 1061-1064
Author(s):  
Xue Gang Ma ◽  
Rong Li Sang ◽  
Yuan Liang Li ◽  
Yi Shen
Keyword(s):  
Electron Microscope ◽  
Chemical Composition ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Lower Cost ◽  
Preparation Method ◽  
Second Phase ◽  
Second Phase Particles ◽  
Tem Method ◽  
Scanning Electron

The microphotograph, size distribution and chemical composition of second phase particles in Q195 steel were characterizated using SEM and EDS. In order to observe the nanometer grade second phase particles, SEM with high resolution should be used. Whether can be second phase particles discovered lies on the preparation method of samples. This method is easier for sample preparation, lower cost, more efficient than TEM method.

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