scholarly journals A Microstructure Investigation of the Deformation and Recrystallization of Particle-Containing Aluminium-Silicon Alloys

1993 ◽  
Vol 20 (1-4) ◽  
pp. 125-140 ◽  
Author(s):  
F. Habiby ◽  
F. J. Humphreys
Keyword(s):  
Single Crystals ◽  
Recrystallization Texture ◽  
Rolling Texture ◽  
Plasticity Theory ◽  
Second Phase ◽  
Slip Systems ◽  
Deformation Bands ◽  
Silicon Alloys ◽  
X Ray ◽  
Second Phase Particles

Single crystals and polycrystals of aluminium containing non-deformable second-phase particles of silicon, have been deformed, and the resultant structures investigated by microscopy and by X-ray and microtexture techniques. The particle size is found to influence the scale of the deformation bands formed, and there is evidence that particles may affect the nucleation of these bands. The deformed materials were recrystallized, and the effect of particle stimulated nucleation on the weakening of the rolling texture is discussed with reference to a computer simulation. In contrast, the recrystallization texture of particle-containing single crystals deformed on only two slip systems is sharp, and it is shown that the texture components are consistent with plasticity theory.

Analytical Electron Microscopy Study of Second-Phase Particles in 7075 and 7475 Aluminum Alloys

1985 ◽  
Vol 43 ◽  
pp. 348-349
Author(s):  
M. Raghavan ◽  
J. Y. Koo ◽  
J. W. Steeds ◽  
B. K. Park
Keyword(s):  
Aluminum Alloys ◽  
Silicon Oxide ◽  
Analytical Electron Microscopy ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Partial Substitution ◽  
Second Phase ◽  
X Ray ◽  
Second Phase Particles ◽  
Almost All

X-ray microanalysis and Convergent Beam Electron Diffraction (CBD) studies were conducted to characterize the second phase particles in two commercial aluminum alloys -- 7075 and 7475. The second phase particles studied were large (approximately 2-5μm) constituent phases and relatively fine ( ∼ 0.05-1μn) dispersoid particles, Figures 1A and B. Based on the crystal structure and chemical composition analyses, the constituent phases found in these alloys were identified to be Al7Cu2Fe, (Al,Cu)6(Fe,Cu), α-Al12Fe3Si, Mg2Si, amorphous silicon oxide and the modified 6Fe compounds, in decreasing order of abundance. The results of quantitative X-ray microanalysis of all the constituent phases are listed in Table I. The data show that, in almost all the phases, partial substitution of alloying elements occurred resulting in small deviations from the published stoichiometric compositions of the binary and ternary compounds.

Thermal Fatigue Mechanism of Welding Deposited Metal of Dies Steels

2007 ◽  
Vol 353-358 ◽  
pp. 2053-2056
Author(s):  
Ren Pei Liu ◽  
Yan Hong Wei ◽  
Wen Hua Chen
Keyword(s):  
Thermal Fatigue ◽  
Experimental Results ◽  
Second Phase ◽  
Slip Systems ◽  
Multiple Slip ◽  
Second Phase Particles ◽  
Deposited Metal ◽  
Deformation Behaviors ◽  
Fatigue Deformation ◽  
Heterogeneous Deformation

This paper conducted the outer constraint test of Coffin thermal fatigue and studied the deformation behaviors of microstructure for two kinds of welding deposited metals, they are 3Cr2W8 and HM3. The experimental results show that the thermal fatigue deformation belongs to multiple slip systems and the heterogeneous deformation mainly concentrates around the second phase particles. Moreover, it is found that the cracking initiation relates to the separation between the second phase particles and base body, void and micro-cracking formation.

Nanoscale Three-Dimensional Microstructural Characterization of an Sn-Rich Solder Alloy Using High-Resolution Transmission X-Ray Microscopy (TXM)

2016 ◽  
Vol 22 (4) ◽  
pp. 808-813 ◽  
Author(s):  
Chandrashekara S. Kaira ◽  
Carl R. Mayer ◽  
V. De Andrade ◽  
Francesco De Carlo ◽  
Nikhilesh Chawla
Keyword(s):  
Fresnel Zone ◽  
Three Dimensional ◽  
Microstructural Characterization ◽  
Second Phase ◽  
Full Field ◽  
X Ray ◽  
Second Phase Particles ◽  
Rich Alloy ◽  
Nanoscale Features

AbstractThree-dimensional (3D) nondestructive microstructural characterization was performed using full-field transmission X-ray microscopy on an Sn-rich alloy, at a spatial resolution of 60 nm. This study highlights the use of synchrotron radiation along with Fresnel zone plate optics to perform absorption contrast tomography for analyzing nanoscale features of fine second phase particles distributed in the tin matrix, which are representative of the bulk microstructure. The 3D reconstruction was also used to quantify microstructural details of the analyzed volume.

scholarly journals Local Textures in Deformed and Recrystallized Aluminium Crystal

1993 ◽  
Vol 20 (1-4) ◽  
pp. 141-154 ◽  
Author(s):  
A. Akef ◽  
J. H. Driver
Keyword(s):  
Single Crystals ◽  
Plane Strain ◽  
Crystal Orientation ◽  
Recrystallization Texture ◽  
True Strain ◽  
Plane Strain Compression ◽  
Deformation Bands ◽  
Transition Band ◽  
Complete Recrystallization

The recrystallization mechanisms in deformed aluminium single crystals have been investigated by SEM microdiffraction techniques (ECP and EBSP). Aluminium crystals of (001)(uv0) and (001)[011-] orientations were deformed in plane strain compression to a true strain of ~1 to develop different deformation microstructures. Transition bands separating deformation bands were formed by orientation splitting in the (001)(uv0) crystals, but were not observed in the (001)[011-] crystal.During annealing at 250°C and 400°C, recrystallization nuclei are developed in both the deformed matrix and along transition bands. Matrix nucleation appears to occur by a subgrain coalescence mechanism according to which the new grains are misoriented 15-30° from the average as-deformed material. Transition band nucleation gives an orientation spread 20-30° around the original, undeformed crystal orientation. A well-defined cube recrystallization texture is obtained at 400°C after complete recrystallization of the initial cube crystal.

scholarly journals The Development of Dislocation Structure and Texture in Rolled Copper (001)[110] Single Crystals

1988 ◽  
Vol 10 (1) ◽  
pp. 67-75 ◽  
Author(s):  
M. Wróbel ◽  
S. Dymek ◽  
M. Blicharski ◽  
S. Gorczyca
Keyword(s):  
Electron Microscopy ◽  
Single Crystals ◽  
Dislocation Structure ◽  
Transverse Direction ◽  
Shear Bands ◽  
Taylor Factor ◽  
Initial Orientation ◽  
Slip Systems ◽  
Deformation Bands ◽  
Pole Figures

The initial orientation has split into two equally strong symmetric orientations: (112)[111¯] and (112)[1¯1¯1]. Areas of identical orientation were band shaped and were called deformation bands. Up to 60% reduction, deformation occurs by slip on one plane (one from two possible) in two directions. This leads to the appearance of deformation bands with transition bands between them. Due to such deformation the initial orientation rotates around transverse direction towards the end-orientation {112}〈111〉. Due to rotation of the crystallographic lattice with deformation, the Taylor factor M changes as well, and it causes the activation of two not coplanar slip systems which stabilize the end-orientations {112}〈111〉. Such a sequence of the slip systems activation was concluded from the agreement of the calculated and experimental pole figures. The electron microscopy investigations showed that first shear bands formed due to the activation of these new slip systems.

Study on the Preparation and Micro Structure of the Mg Containing Porous HA with Ultra-Fine Grain

2009 ◽  
Vol 610-613 ◽  
pp. 1132-1136
Author(s):  
Xing Yi Li ◽  
Xiang Cai Meng ◽  
Guo Quan Liu ◽  
Shi Dan Yuan
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Chemical Precipitation ◽  
Second Phase ◽  
X Ray Diffraction ◽  
Micro Structure ◽  
X Ray ◽  
Fine Grain ◽  
Transmission Electron ◽  
Second Phase Particles

The Nano-HA powder were synthesized by chemical precipitation with Ca(H2PO4)2•H2O and Ca (OH)2 and porous HA was prepared by sintering with magnesium as pore-creator. Nano-HA powder and porous HA were characterized by wide angle X-ray diffraction, transmission electron microscopy(TEM), scanning electron microscopy (SEM), SEM in combination with energy dispersive X-ray spectroscopy (SEM-EDX), X-ray photoelectron spectroscopy. The experimental results show that HA powder synthesized by chemical precipitation is nanometer powder. Magnesium was ideal pore-creator for preparation of porous materials. The grain size of porous HA was sub-micron and MgO which existed in the grain boundary of HA as a second phase particles that played the roles of inhibiting the HA grain growth.

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