Grain Size Control in the Weld Pool and Heat Affected Zone Using Holograms

This paper considers the use of Holographic Optical Elements (HOEs) to shape the weld beam and hence control the grain size of the weld bead and the grain growth and phase transformations in the HAZ. Welds have been produced on carbon steel with the introduction of a nickel based filler powder, using different energy densities produced by the HOEs. Cross sections of the welds have been analysed in terms of the weld profile, weld pool shape and grain size in the deposit and the HAZ. Electron BackScatter Diffraction (EBSD) coupled with Energy Dispersive X-ray Spectroscopy (EDS) has been used to study the microstructures developed. The results have shown that by utilising HOEs the grain size within the weld pool can be controlled such that a more equiaxed grain structure is developed when compared with the coarse columnar grains seen with a Gaussian beam.

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Weld Pool Shaping and Microstructural Control Using Novel Computer Generated Holographic Optic Laser Welding of Steel and Stainless Steel

Materials Science Forum ◽

10.4028/www.scientific.net/msf.638-642.3673 ◽

2010 ◽

Vol 638-642 ◽

pp. 3673-3678 ◽

Cited By ~ 8

Author(s):

R.L. Higginson ◽

M. Gibson ◽

J. Kell ◽

J. Tyrer

Keyword(s):

Weld Pool ◽

Cross Sections ◽

Electron Backscatter Diffraction ◽

Plain Carbon Steel ◽

Grain Structure ◽

Optical Elements ◽

Pool Shape ◽

Columnar Grains ◽

And Control ◽

Weld Pool Shape

This work considers the use of Holographic Optical Elements (HOEs) to shape the weld beam and control the microstructure of the weld bead. The beam profiles investigated are a standard Gaussian and an Offset Rugby Post produced by a HOE. Autogenous welds have been produced on plain carbon steel with the introduction of a nickel alloy filler powder, using different energy densities. Cross sections of the welds have been analysed in terms of the weld profile, weld pool shape, HAZ and the extent of the deposit/substrate mixing. Electron BackScatter Diffraction (EBSD) coupled with Energy Dispersive X-ray Spectroscopy (EDS) has been used to study the microstructures developed. The results have shown that by utilising HOE’s the weld pool shape can be modified so that a squarer profile can be obtained. The grain structure within the weld pool can be controlled such that a finer more equiaxed grain structure can be developed when compared with the coarse columnar grains seen with a Gaussian beam with a marked difference in the microstructures in the HAZ.

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Characterization of Nanostructured Electrodeposited NiCo Samples by use of Electron Backscatter Diffraction (EBSD)

MRS Proceedings ◽

10.1557/proc-880-bb1.3 ◽

2005 ◽

Vol 880 ◽

Author(s):

Alice Bastos ◽

Dierk Raabe ◽

Stefan Zaefferer ◽

Christopher Schuh

Keyword(s):

Grain Size ◽

Cross Sections ◽

Electron Backscatter Diffraction ◽

Growth Direction ◽

Grain Structure ◽

Local Texture ◽

Average Grain Size ◽

Electron Backscatter ◽

Backscatter Diffraction

AbstractA Cobalt-20wt.% Nickel polycrystal produced by electrodeposition has been investigated in planar and cross sections using a high resolution scanning electron microscope. The local texture, grain size, amount of phase and grain boundaries, were characterized by Electron Backscatter Diffraction (EBSD). The average grain size perpendicular to the grain growth direction was 400 nm. Parallel to it, a pronounced bimodal grain structure was observed with grains reaching more than 10 μm and grains of approximately 800 nm diameter.

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Cross Section Analysis of Cu Filled TSVs Based on High Throughput Plasma-FIB Milling

ISTFA 2012: Conference Proceedings from the 38th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2012p0039 ◽

2012 ◽

Author(s):

Frank Altmann ◽

Jens Beyersdorfer ◽

Jan Schischka ◽

Michael Krause ◽

German Franz ◽

...

Keyword(s):

High Resolution ◽

Cross Section ◽

High Throughput ◽

Cross Sections ◽

Electron Backscatter Diffraction ◽

Grain Structure ◽

Electron Backscatter ◽

Section Surface ◽

Backscatter Diffraction ◽

Section Analysis

Abstract In this paper the new Vion™ Plasma-FIB system, developed by FEI, is evaluated for cross sectioning of Cu filled Through Silicon Via (TSV) interconnects. The aim of the study presented in this paper is to evaluate and optimise different Plasma-FIB (P-FIB) milling strategies in terms of performance and cross section surface quality. The sufficient preservation of microstructures within cross sections is crucial for subsequent Electron Backscatter Diffraction (EBSD) grain structure analyses and a high resolution interface characterisation by TEM.

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Three-dimensional virtual grain structure generation with grain size control

Mechanics of Materials ◽

10.1016/j.mechmat.2012.08.005 ◽

2012 ◽

Vol 55 ◽

pp. 89-101 ◽

Cited By ~ 15

Author(s):

P. Zhang ◽

M. Karimpour ◽

D. Balint ◽

J. Lin

Keyword(s):

Grain Size ◽

Three Dimensional ◽

Size Control ◽

Grain Structure ◽

Structure Generation ◽

Grain Size Control

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Effect of Annealing on Microstructural Development and Grain Orientation in Electrodeposited Ni

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.160.235 ◽

2010 ◽

Vol 160 ◽

pp. 235-240 ◽

Cited By ~ 5

Author(s):

Uta Klement ◽

L. Hollang ◽

S.R. Dey ◽

M. Battabyal ◽

O.V. Mishin ◽

...

Keyword(s):

Grain Growth ◽

Cross Sections ◽

Electron Backscatter Diffraction ◽

Microstructural Development ◽

Growth Behaviour ◽

Coalescence Model ◽

Transmission Electron ◽

Columnar Grains ◽

Backscatter Diffraction

Thick (up to 5 mm) Ni electrodeposits were produced by the pulsed electrodeposition (PED) technique. The PED-Ni was investigated in planar and cross-sections using high resolution scanning electron microscopy. Grain size and local texture were studied by electron backscatter diffraction. Thermal stability and grain growth behaviour were investigated using in-situ annealing in the transmission electron microscope. It is observed that columnar grains are present in the material and that the orientation of grains is not uniform. Textures and in-situ annealing behaviour are compared to previous data on nanocrystalline PED-Ni and Ni-Fe, where a subgrain coalescence model adopted from recrystallization is used to describe the occurrence of abnormal grain growth upon annealing and where twinning was found to be responsible for the texture development.

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Interfacial studies in Nb3Sn superconductors

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100087264 ◽

1991 ◽

Vol 49 ◽

pp. 590-591

Author(s):

Ernest L. Hall ◽

Lee E. Rumaner ◽

Mark G. Benz

Keyword(s):

Grain Size ◽

Grain Boundaries ◽

Flux Pinning ◽

Size Control ◽

High Magnetic Fields ◽

Type Ii ◽

Reaction Interface ◽

Liquid Diffusion ◽

Type Ii Superconductor ◽

Grain Size Control

The intermetallic compound Nb3Sn is a type-II superconductor of interest because it has high values of critical current density Jc in high magnetic fields. One method of forming this compound involves diffusion of Sn into Nb foil containing small amounts of Zr and O. In order to maintain high values of Jc, it is important to keep the grain size in the Nb3Sn as small as possible, since the grain boundaries act as flux-pinning sites. It has been known for many years that Zr and O were essential to grain size control in this process. In previous work, we have shown that (a) the Sn is transported to the Nb3Sn/Nb interface by liquid diffusion along grain boundaries; (b) the Zr and O form small ZrO2 particles in the Nb3Sn grains; and (c) many very small Nb3Sn grains nucleate from a single Nb grain at the reaction interface. In this paper we report the results of detailed studies of the Nb3Sn/Nb3Sn, Nb3Sn/Nb, and Nb3Sn/ZrO2 interfaces.

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