Spatially resolved on-line monitoring during laser beam welding of steel and aluminum

2004 ◽  
Author(s):  
Jürgen Müller-Borhanian ◽  
Christoph Deininger ◽  
Friedrich H. Dausinger ◽  
Helmut Hügel
Keyword(s):  
Laser Beam ◽  
Laser Beam Welding ◽  
Spatially Resolved ◽  
On Line

The Studies of Plasma Torch Processes by Laser Beam Welding

2017 ◽  
Vol 893 ◽  
pp. 190-194
Author(s):  
Igor Yu. Letyagin ◽  
Dmitriy Trushnikov ◽  
Vladimir Ya. Belenkiy
Keyword(s):  
Laser Beam ◽  
Thermal Processing ◽  
Plasma Torch ◽  
Laser Beam Welding ◽  
Melting Process ◽  
Work Piece ◽  
Testing Procedures ◽  
On Line

The manufacturing of significant products with help of laser beam welding technologies requires higher stability characteristics of such technologies; this explains the necessity to run on-line testing procedures of through pro-melting process. This type of testing can be carried out by the registration of plasma streams that occur under a work piece by through pro-melting [i.e. metal undergoes an intensive laser beam thermal processing].

On-line monitoring of penetration depth in laser beam welding

1997 ◽  
Author(s):  
J. Beersiek ◽  
R. Poprawe ◽  
W. Schulz ◽  
Hongping Gu ◽  
R. E. Mueller ◽  
...  
Keyword(s):  
Laser Beam ◽  
Penetration Depth ◽  
Laser Beam Welding ◽  
On Line

Recent Progress and Plans in Computer-Controlled High Resolution Electron Microscopy

1990 ◽  
Vol 48 (1) ◽  
pp. 154-155
Author(s):  
W.J. de Ruijter ◽  
Peter Rez ◽  
David J. Smith
Keyword(s):  
Electron Microscopy ◽  
Digital Processing ◽  
High Resolution Electron Microscopy ◽  
Objective Lens ◽  
Linear Filter ◽  
Contrast Transfer Function ◽  
Image Displacement ◽  
Spatially Resolved ◽  
Wide Range ◽  
On Line

Digital computers are becoming widely recognized as standard accessories for electron microscopy. Due to instrumental innovations the emphasis in digital processing is shifting from off-line manipulation of electron micrographs to on-line image acquisition, analysis and microscope control. An on-line computer leads to better utilization of the instrument and, moreover, the flexibility of software control creates the possibility of a wide range of novel experiments, for example, based on temporal and spatially resolved acquisition of images or microdiffraction patterns. The instrumental resolution in electron microscopy is often restricted by a combination of specimen movement, radiation damage and improper microscope adjustment (where the settings of focus, objective lens stigmatism and especially beam alignment are most critical). We are investigating the possibility of proper microscope alignment based on computer induced tilt of the electron beam. Image details corresponding to specimen spacings larger than ∼20Å are produced mainly through amplitude contrast; an analysis based on geometric optics indicates that beam tilt causes a simple image displacement. Higher resolution detail is characterized by wave propagation through the optical system of the microscope and we find that beam tilt results in a dispersive image displacement, i.e. the displacement varies with spacing. This approach is valid for weak phase objects (such as amorphous thin films), where transfer is simply described by a linear filter (phase contrast transfer function) and for crystalline materials, where imaging is described in terms of dynamical scattering and non-linear imaging theory. In both cases beam tilt introduces image artefacts.

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