The effect of workpiece cooling on the machining of biomedical grade polymers
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2014Access:
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Barry Aldwell, Jimmy O'Mahony, Garret Edward O'Donnell, The effect of workpiece cooling on the machining of biomedical grade polymers, 9th CIRP Conference on Intelligent Computation in Manufacturing Engineering, 2014Download Item:
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Abstract:
Biomedical grade polymers are commonly used in applications where surface finish and dimensional accuracy are key, such as in t
otal joint
replacement and intraocular lenses, yet relatively little research
has been conducted into the machining of these materials. It
has been
established that workpiece temperature has a lar
ge effect on machinability in soft polymers
,
with alterations to the chip formation mechanism
p
ossible when workpiece temperature is adequately controlled. This
is due to the change in material behaviour at the glass tran
sition
temperature, which varies with the composition and crystallinity
of the polymer. In polymers which have low glass transition te
mperatures,
liquid nitrogen cooling is used, in some cases with a control system used to regulate the workpiece temperature during machinin
g. This work
concentrates on the machining of Ultra High Molecular Weig
ht Polyethylene (UHMWPE) workpieces which have been pre
-
cooled before
mach
ining. Past work has concentrated on the development of a measurement chain for the monitoring of polymer machining, and
characterising the machining of UHMWPE at ambient temperature, wh
ile varying tool and process parameters. Little work has been
done on
the cryogenic machining of UHMWPE, though it is known that the hi
gh crystallinity of UHMWPE alters thermomechanical behaviour w
hen
compared to conventional blends of polyethylene, and
the glass transition temperature is in the region of
-
120°C. The aim of this work is to
p
rovide insight into the effect of workpiece temper
ature on machinability and surface quality in UHMWPE.
Author's Homepage:
http://people.tcd.ie/aldwelbahttp://people.tcd.ie/odonnege
Description:
PUBLISHED
Author: ALDWELL, BARRY; O'DONNELL, GARRET
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9th CIRP Conference on Intelligent Computation in Manufacturing EngineeringType of material:
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