Macro and Microstructural Effects of the Application of an Induced Axial Magnetic Field During the Deposition of Aluminum Weld Beads

2009 ◽  
Vol 1242 ◽  
Author(s):  
M. A. García ◽  
V. H. López M. ◽  
R. García H. ◽  
F. F. Curiel L. ◽  
R. R. Ambríz R.
Keyword(s):  
Magnetic Field ◽  
Grain Size ◽  
Magnetic Fields ◽  
Weld Metal ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Axial Magnetic Field ◽  
Grain Structure ◽  
Bead Geometry ◽  
External Power Source

ABSTRACTIn this work, aluminum weld beads were deposited on aluminum plates of commercial purity (12.7 mm thick), using an ER-5356 filler wire. The aim of the experiments was to assess the effects that yield the induction of an axial magnetic field (AMF) during the application of the weld beads using the direct current gas metal arc welding process (DC-GMAW). An external power source was use to induce magnetic fields between 0 to 28 mT. The effects of the magnetic fields were assessed in terms of the macrostructural features of the deposits, morphology of the grain structure, grain size and grain size distribution in the weld metal. Macrostructural characteristics of the weld beads revealed that increasing the intensity of the magnetic induction to produce a magnetic field above 14 mT, leads to a significant loss of feeding material and there is a tendency of the deposits to increase their width and reduce penetration. Perturbation of the weld pool induced by the application of the AMF noticeably modified the grain structure in the weld metal. In particular, for the intensities of 5 and 14 mT, columnar growth was essentially non-existent. Grain size distribution plots showed, generally speaking, that the use of magnetic fields is an efficient method to produce homogeneous grain structures within the weld metal. Finite element analysis was used to explain the weld bead geometry with the intensity of the magnetic field.

scholarly journals EXPERIMENTAL EVALUATION OF STEREOLOGICAL METHODS FOR DETERMINING 3D GRAIN SIZE AND TOPOLOGICAL DISTRIBUTIONS

2011 ◽  
Vol 19 (2) ◽  
pp. 91 ◽  
Author(s):  
Guoquan Liu ◽  
Haibo Yu
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Experimental Evaluation ◽  
Single Phase ◽  
Experimental Methods ◽  
Grain Structure ◽  
Serial Sectioning ◽  
Topological Parameters ◽  
Selection Of

The conventional serial sectioning analysis and a set of modern stereological methods, including disector, selector, point-sampled intercepts, point-sampled area, and their combinations, have been used in this paper to measure the grain size, grain size distribution, topological parameters and their distributions in a spacefilling single-phase grain structure of steel. The results from different methods are compared and used to evaluate the methods quantitatively, based on which some suggestions will be given for selection of experimental methods in materials stereology research.

Statistical analysis of the parameters and grain size distribution functions of single-phase polycrystalline materials

2020 ◽  
Vol 86 (4) ◽  
pp. 39-45
Author(s):  
S. I. Arkhangelskiy ◽  
D. M. Levin
Keyword(s):  
Grain Size ◽  
Distribution Function ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Single Phase ◽  
Distribution Functions ◽  
Grain Structure ◽  
Polycrystalline Materials ◽  
Grain Sizes ◽  
Average Grain Size

A statistical analysis of the grain size distribution is important both for developing theories of the grain growth and microstructure formation, and for describing the size dependences of various characteristics of the physical and mechanical properties of polycrystalline materials. The grain size distribution is also an important characteristic of the structure uniformity and, therefore, stability of the properties of the products during operation. Statistical Monte Carlo modeling of single-phase and equiaxed polycrystalline microstructures was carried out to determine the type of statistically valid distribution function and reliable estimates of the average grain size. Statistical parameters (mean values, variances, variation coefficient) and distribution functions of the characteristics of the grain microstructure were obtained. It is shown that the distribution function of the effective grain sizes for the studied polycrystal model is most adequately described by γ-distribution, which is recommended to be used in analysis of the experimental distribution functions of grain sizes of single-phase polycrystalline materials with equiaxed grains. The general average (mathematical expectation) of the effective grain size (projection diameter) with γ-distribution function (parameters of the distribution function are to be previously determined in analysis of the grain structure of polycrystalline materials) should be taken as a statistically valid and reliable estimate of the average grain size. The results of statistical modeling are proved by the experimental data of metallographic study of the microstructures of single-phase model and industrial materials with different degree of the grain structure heterogeneity.

Statistical Analysis of Histograms of Grain Size Distribution in Nanostructured Materials Processed by Severe Plastic Deformation

2018 ◽  
Vol 284 ◽  
pp. 431-435 ◽  
Author(s):  
Alexey V. Stolbovsky ◽  
Elena Farafontova
Keyword(s):  
Plastic Deformation ◽  
Grain Size ◽  
Statistical Analysis ◽  
Severe Plastic Deformation ◽  
Size Distribution ◽  
Nanostructured Materials ◽  
Grain Size Distribution ◽  
Grain Structure ◽  
Standard Distribution ◽  
Statistical Analysis Methods

Analysis of histograms of grain size distribution of materials nanostructured by severe plastic deformation has been carried out using statistical analysis methods. It has been established that in materials with quite homogeneous nanostructure, the fitting of histograms of grain size distribution by using a logarithmic standard distribution is not accurate enough. It is proposed to compensate for the observed imprecision by including into the model the additional component – normal distribution. It is shown that this approach is applicable to nanostructured materials with both the deformation-origin nanostructure and the grain structure formed during annealing.

Control of Microstructure by Laser Spot Heating

2007 ◽  
Vol 127 ◽  
pp. 337-342 ◽  
Author(s):  
Toshiya Shibayanagi ◽  
Masahiro Tsukamoto ◽  
N. Matsuda ◽  
Y. Soga ◽  
Nobuyuki Abe ◽  
...  
Keyword(s):  
Computer Simulation ◽  
Grain Size ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Laser System ◽  
Grain Structure ◽  
Laser Spot ◽  
Heating Process ◽  
Polycrystalline Aluminum ◽  
Different Grain Size

The present study tried to control grain structure in polycrystalline aluminum or titanium by means of a laser spot heating method as well as by a computer simulation technique. Monte Carlo simulation of spot heating was performed utilizing two-dimensional grain structure model composed of 200 x 200 sites with hexagonal cells. Grain growth proceeded preferentially in the higher temperature region and resulted in a large grain surrounded by small grains. This large grain tended to keep on growing during homogeneous heating after the spot heating, suggesting that the spot heating technique can fabricate a peculiar grain structure such as different grain size distribution and texture that are not realized by utilizing conventional uniform heating process. Laser spot heating utilizing a fiber-laser system realized heating of small area such as 30micorn diameter to bring about peculiar grain size distribution as calculated by the computer simulation.

Grain Growth, Stress, and Impurities in Electroplated Copper

2002 ◽  
Vol 17 (3) ◽  
pp. 582-589 ◽  
Author(s):  
S. H. Brongersma ◽  
E. Kerr ◽  
I. Vervoort ◽  
A. Saerens ◽  
K. Maex
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Grain Growth ◽  
Sheet Resistance ◽  
Grain Size Distribution ◽  
High Temperatures ◽  
Intermediate State ◽  
Growth Stress ◽  
Grain Structure ◽  
Electroplated Copper

The widely observed secondary grain growth in electroplated Copper layers is shown to be incomplete after the sheet resistance and stress of the layer appear to have stabilized. Instead the layer is in an intermediate state with a grain size distribution that depends on the plating conditions. Further extensive annealing at high temperatures results in an additional considerable enlargement of the grain structure, accompanied by an additional decrease of the sheet resistance and desorption of impurities that were incorporated during plating.

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