Material ratio curve as information on the state of surface topography—A review

Currently, the surface integrity-related issues of additively manufactured parts are limiting the potential high-end applications. The present work investigates the effectiveness of the pulsed-electropolishing technique to improve the surface integrity of aluminium alloys fabricated using the selective laser melting (SLM) technique. Due to its low density, high corrosion resistance, the aluminium alloys considerably enhance the performance of lightweight critical parts for different industrial applications. In this study, selective laser melted AlSi10Mg samples were subjected to microstructural examinations using optical microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction technique. The microhardness and tensile properties were determined using a microhardness tester and a universal testing machine, respectively. The pulsed-electropolishing process was employed for the surface finishing of the SLM-processed AlSi10Mg samples. The effect of current density on the electropolishing of selective laser melted AlSi10Mg alloy were also investigated. The microstructures of printed samples revealed a density of greater than 99.9% and weld beads along the build direction (longitudinal) and laser scan paths perpendicular to the build direction (transverse). The microhardness, yield and tensile strength properties were similar in both as-printed conditions. The pulsed electropolishing results showed a beneficial effect of higher current density values, resulting in decreased surface roughness of the SLM-processed AlSi10Mg samples. Compared to as-printed conditions, a significant decrease in surface roughness of about ∼73.35% under optimized electropolishing conditions was noted. The material ratio curve shows that the surface topography becomes more uniform with increased current density and has lesser surface undulations for as-printed samples. The 2D line profilogram and 3D surface topography of electropolished SLM-processed samples reveal the surface finish quality characteristics. The material ratio curve aids as an effective method to assess and qualify the surface topography of electropolished samples.

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Surface topography in autobody manufacture—the state of the art

Proceedings of the Institution of Mechanical Engineers Part B Journal of Engineering Manufacture ◽

10.1243/0954405001517883 ◽

2000 ◽

Vol 214 (9) ◽

pp. 811-820 ◽

Cited By ~ 6

Author(s):

F Sacerdotti ◽

B J Griffiths ◽

C Butler ◽

F Benati

Keyword(s):

Surface Topography ◽

State Of The Art ◽

The State

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Money, Markets, and the State: Social Democratic Economic Policies since 1918. By Ton Notermans. Cambridge: Cambridge University Press, 2000. Pp. xix, 302. $59.95.

The Journal of Economic History ◽

10.1017/s0022050700003971 ◽

2001 ◽

Vol 61 (2) ◽

pp. 586-588

Author(s):

Kenneth Mour??

Keyword(s):

The State ◽

Economic Policies ◽

Money Markets ◽

Social Democratic ◽

Cambridge University

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A History of Brewing in Holland, 9001900: Economy, Technology and the State. By Richard W. Unger. Leiden: Brill, 2001. Pp. xxii, 428. 140, $154.00.

The Journal of Economic History ◽

10.1017/s0022050703542048 ◽

2003 ◽

Vol 63 (3) ◽

pp. 867-868

Author(s):

ARJAN POELWIJK

Keyword(s):

The State ◽

History Of

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The Broad Applications of the Scanning Electron Microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100062002 ◽

1969 ◽

Vol 27 ◽

pp. 20-21

Author(s):

C. T. Nightingale ◽

S. E. Summers ◽

T. P. Turnbull

Keyword(s):

Electron Microscope ◽

Scanning Electron Microscope ◽

Light Microscopy ◽

Surface Topography ◽

Great Depth ◽

Resolving Power ◽

Depth Of Field ◽

Pictorial Representations ◽

Scanning Electron

The ease of operation of the scanning electron microscope has insured its wide application in medicine and industry. The micrographs are pictorial representations of surface topography obtained directly from the specimen. The need to replicate is eliminated. The great depth of field and the high resolving power provide far more information than light microscopy.

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Effects of Ion Beam Milling on Surface Topography

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100070862 ◽

1973 ◽

Vol 31 ◽

pp. 84-85

Author(s):

P.G. Pawar ◽

P. Duhamel ◽

G.W. Monk

Keyword(s):

Surface Topography ◽

Ion Beam ◽

Solid Material ◽

Beam Current ◽

Atomic Mass ◽

Micro Milling ◽

Ion Milling ◽

Controlled Atmospheres ◽

Milling Operations ◽

Sufficient Energy

A beam of ions of mass greater than a few atomic mass units and with sufficient energy can remove atoms from the surface of a solid material at a useful rate. A system used to achieve this purpose under controlled atmospheres is called an ion miliing machine. An ion milling apparatus presently available as IMMI-III with a IMMIAC was used in this investigation. Unless otherwise stated, all the micro milling operations were done with Ar+ at 6kv using a beam current of 100 μA for each of the two guns, with a specimen tilt of 15° from the horizontal plane.It is fairly well established that ion bombardment of the surface of homogeneous materials can produce surface topography which resembles geological erosional features.

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Practical Picture Processing

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100051700 ◽

1974 ◽

Vol 32 ◽

pp. 338-339

Author(s):

T. A. Welton

Keyword(s):

Radiation Damage ◽

Coherence Length ◽

Spatial Information ◽

State Of The Art ◽

Coherent Radiation ◽

The State ◽

Energy Spread ◽

Electron Micrograph ◽

Picture Processing ◽

Molecular Skeleton

Various authors have emphasized the spatial information resident in an electron micrograph taken with adequately coherent radiation. In view of the completion of at least one such instrument, this opportunity is taken to summarize the state of the art of processing such micrographs. We use the usual symbols for the aberration coefficients, and supplement these with £ and 6 for the transverse coherence length and the fractional energy spread respectively. He also assume a weak, biologically interesting sample, with principal interest lying in the molecular skeleton remaining after obvious hydrogen loss and other radiation damage has occurred.

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Low-Loss Images in a Stem/Tem Microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010009244x ◽

1976 ◽

Vol 34 ◽

pp. 496-497 ◽

Cited By ~ 1

Author(s):

David C. Joy ◽

Dennis M. Maher

Keyword(s):

High Resolution ◽

Surface Topography ◽

Beam Direction ◽

Low Loss ◽

Specimen Holder ◽

Glancing Angle ◽

High Resolution Images ◽

Set Up ◽

Conventional Manner ◽

Objective Type

High-resolution images of the surface topography of solid specimens can be obtained using the low-loss technique of Wells. If the specimen is placed inside a lens of the condenser/objective type, then it has been shown that the lens itself can be used to collect and filter the low-loss electrons. Since the probeforming lenses in TEM instruments fitted with scanning attachments are of this type, low-loss imaging should be possible.High-resolution, low-loss images have been obtained in a JEOL JEM 100B fitted with a scanning attachment and a thermal, fieldemission gun. No modifications were made to the instrument, but a wedge-shaped, specimen holder was made to fit the side-entry, goniometer stage. Thus the specimen is oriented initially at a glancing angle of about 30° to the beam direction. The instrument is set up in the conventional manner for STEM operation with all the lenses, including the projector, excited.

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