11-04-2012, 02:48 PM
Abrasive flow machining performance measures on work-piece surfaces
having different vent/passage considerations for media outflow
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INTRODUCTION
AFM is an advanced machining process [1] that is
used to debur, radius, polish, remove recast layer, and
to produce compressive residual stresses. The process is
gaining widespread attention due to its ability to
produce consistent and predictable results and its wide
scope of practical applications; anywhere that the media
can be forced to flow represents a practical application
of AFM process. In this process, an abrasive laden
pliable semi-solid compound is forced to flow across
the work-piece surface to be machined. Abrasion occurs
wherever the medium passes through the highly
restrictive passage.
Procedure
The experiments were performed and micromachining
by AFM technique conducted on cylindrical
work-piece surfaces of varying cross-sections and
lengths having single vent/passage, three vents/passage
& five vents/passages for media outflow with brass as
work material. For preparing these specimens, the
brass section is machined at the predetermined cutting
conditions. The other/inner side of the section is
milled to get the required passage geometry. From this
section, the pieces are cut in the desired size and then
filed so as to make them of desirable dimensions.
EXPERIMENTAL SETUP AND PROCEDURE
Fig.1 shows an assembly drawing of the table-top
setup for an AFM process, designed and fabricated by
the authors. The setup is mounted on the work table
with the help of steady rests. The configuration is a
single cylinder, one-way AFM setup which comprises
of single media cylinder,
CONCLUSIONS
The following conclusions have been derived from
the above study:
1. Vent/passage considerations for media outflow in
work-piece surface significantly affects
performance measures, material removal (MR) and
surface roughness (Ra value) in abrasive flow
machining.
2. Micro machining work-piece surfaces having
single vent/passage for media outflow by abrasive
flow machining produced better results in
comparison with work-piece surfaces having
multiple vents.
3. Work-piece surfaces having single vent/passage for
media outflow have higher material removal and
more improvement in surface roughness and the
performance measures decrease with increase in
the number of vents for media outflow.
4. The change in surface roughness, ΔRa increases
with the increase in length of the work-piece and
decreases with the increase in cross section of the
work-piece.