Research was conducted to evaluate a microtrenching process to create microchannels on the surface of poly (methyl methacrylate) (PMMA) for applications in tissue engineering. Experiments with a trenching tool included an exaggerated cutting edge radius (48 μm) to study the impact of a highly negative effective rake angle on forces during single pass microtrenching at subradius cutting conditions. During microtrenching, forces were measured by dynamometer and compared to a finite element (FE) model using an elastic-perfectly plastic material model for an undeformed chip thickness from 9 to 64 μm. During experiments, cutting was first observed when the ratio of undeformed chip thickness to cutting edge radius was 0.33. Measured and predicted values of thrust force exceeded cutting force up to an undeformed chip thickness equivalent to the cutting edge radius. The FE model predicted a linear trend in cutting force with feed (r = 0.99) and was substantiated by linear regression of experimental data (r = 0.99). However, at lower values of feed the model overestimated force, with a maximum difference of 42% at a feed of 22 μm. Thrust force was also predicted to be linear (r = 0.99), but at greater feed the experiments indicated a nonlinear decline in thrust force, resulting in a maximum difference of 27% at 64 μm. Finally, an analysis of nodal velocity plots from the FE model revealed a material stagnation zone developed along the cutting edge, rising from the workpiece surface in proportion to feed and then remaining fixed at 63 deg (stagnation angle) for all feeds greater than 35 μm. While the application of an elastic-perfectly plastic material model for PMMA was sufficient to predict microtrenching forces by the FE method, differences between predicted and measured thrust forces at greater undeformed chip thickness implies a more complex rheological model may add value.

References

References
1.
Sachlos
,
E.
, and
Czernuszka
,
J. T.
,
2003
, “
Making Tissue Engineering Scaffolds Work: Review on the Application of Solid Freeform Fabrication Technology to the Production of Tissue Engineering Scaffolds
,”
Eur. Cells Mater.
,
5
, pp.
29
40
.
2.
Vidaurre
,
A.
,
Cortazar
,
C.
, and
Ribelles
,
J. L. G.
,
2007
, “
Polymeric Scaffolds With a Double Pore Structure
,”
J. Non-Cryst. Solids
,
353
(
11–12
), pp.
1095
1100
.10.1016/j.jnoncrysol.2006.12.110
3.
Park
,
H.
,
Larson
,
B. L.
,
Guillemette
,
M. D.
,
Jain
,
S. R.
,
Hua
,
C.
,
Engelmayr
,
G. C.
, and
Freed
,
L. E.
,
2011
, “
The Significance of Pore Microarchitecture in a Multi-Layered Elastomeric Scaffold for Contractile Cardiac Muscle Constructs
,”
Biomaterials
,
32
(
7
), pp.
1856
1864
.10.1016/j.biomaterials.2010.11.032
4.
Albrecht
,
P.
,
1960
, “
New Development in the Theory of Metal-Cutting Process, Part I. The Ploughing Process in Metal Cutting
,”
ASME J. Eng. Ind.
,
82
(
4
), pp.
348
357
.10.1115/1.3664242
5.
Basuray
,
P. K.
,
Misra
,
B. K.
, and
Lal
,
G. K.
,
1977
, “
Transition From Ploughing to Cutting During Machining With Blunt Tools
,”
Wear
,
43
(
3
), pp.
341
349
.10.1016/0043-1648(77)90130-2
6.
Waldorf
,
D. J.
,
DeVor
,
R. E.
, and
Kapoor
,
S. G.
,
1998
, “
A Slip-Line Field for Ploughing During Orthogonal Cutting
,”
ASME J. Manuf. Sci. Eng.
,
120
(
4
), pp.
693
699
.10.1115/1.2830208
7.
Liu
,
X.
,
DeVor
,
R. E.
,
Kapoor
,
G. G.
, and
Ehmann
,
K. F.
,
2004
, “
The Mechanics of Machining at the Microscale: Assessment of the Current State of the Science
,”
ASME J. Manuf. Sci. Eng.
,
126
(
4
), pp.
666
678
.10.1115/1.1813469
8.
Waldorf
,
D. J.
,
DeVor
,
R. E.
, and
Kapoor
,
S. G.
,
1999
, “
An Evaluation of Ploughing Models for Orthogonal Machining
,”
ASME J. Manuf. Sci. Eng.
,
121
(
4
), pp.
550
558
.10.1115/1.2833050
9.
Kim
,
C.-J.
,
Mayor
,
J. R.
, and
Ni
,
J.
,
2005
, “
A Static Model of Chip Formation in Microscale Milling
,”
ASME J. Manuf. Sci. Eng.
,
126
(
4
), pp.
710
718
.10.1115/1.1813475
10.
Chae
,
J.
,
Park
,
S. S.
, and
Freiheit
,
T.
,
2006
, “
Investigation of Micro-Cutting Operations
,”
Int. J. Mach. Tool Manuf.
,
46
(
3–4
), pp.
313
332
.10.1016/j.ijmachtools.2005.05.015
11.
Aramcharoen
,
A.
, and
Mativenga
,
P. T.
,
2009
, “
Size Effect and Tool Geometry in Micromilling of Tool Steel
,”
Precis. Eng.
,
33
(
4
), pp.
402
407
.10.1016/j.precisioneng.2008.11.002
12.
Briscoe
,
B. J.
,
Evans
,
P. D.
,
Pelillo
,
E.
, and
Sinha
,
S. K.
,
1996
, “
Scratching Maps for Polymers
,”
Wear
,
200
(
1–2
), pp.
137
147
.10.1016/S0043-1648(96)07314-0
13.
Jardret
,
V.
, and
Morel
,
P.
,
2003
, “
Viscoelastic Effects on the Scratch Resistance of Polymers: Relationship Between Mechanical Properties and Scratch Properties at Various Temperatures
,”
Prog. Org. Coat.
,
43
(
2–4
), pp.
322
331
.10.1016/j.porgcoat.2003.02.002
14.
Pelletier
,
H.
,
Gauthier
,
C.
, and
Schirrer
,
R.
,
2010
, “
Relationship Between Contact Geometry and Average Plastic Strain During Scratch Tests on Amorphous Polymers
,”
Tribol. Int.
,
43
(
4
), pp.
796
809
.10.1016/j.triboint.2009.11.006
15.
Sinha
,
S. K.
, and
Lim
,
D. B. J.
,
2006
, “
Effects of Normal Load on Single-Pass Scratching of Polymer Surface
,”
Wear
,
260
(
7–8
), pp.
751
765
.10.1016/j.wear.2005.04.018
16.
Gauthier
,
C.
,
Lafaye
,
S.
, and
Schirrer
,
R.
,
2000
, “
Time and Temperature Dependence of the Scratch Properties of Poly(methylmethacrylate) Surfaces
,”
J. Mater. Sci.
,
35
(
9
), pp.
2121
2130
.10.1023/A:1004798019914
17.
Bucaille
,
J. L.
,
Gauthier
,
C.
,
Felder
,
E.
, and
Schirrer
,
R.
,
2006
, “
The Influence of Strain Hardening of Polymers on the Piling-up Phenomenon in Scratch Tests: Experiments and Numerical Modeling
,”
Wear
,
260
(
7–8
), pp.
803
814
.10.1016/j.wear.2005.04.007
18.
Marusich
,
T. D.
, and
Ortiz
,
M.
,
1995
, “
Modeling and Simulation of High-Speed Machining
,”
Int. J. Numer. Methods Eng.
,
38
(
21
), pp.
3675
3694
.10.1002/nme.1620382108
19.
Yuan
,
Z. J.
,
Zhou
,
M.
, and
Dong
,
S.
,
1996
, “
Effect of Diamond Tool Sharpness on Minimum Cutting Thickness and Cutting Surface Integrity in Ultraprecision Machining
,”
J. Mater. Process. Technol.
,
62
(
4
), pp.
327
330
.10.1016/S0924-0136(96)02429-6
20.
Son
,
S. M.
,
Lim
,
H. S.
, and
Ahn
,
J. H.
,
2005
, “
Effects of the Friction Coefficient on the Minimum Cutting Thickness in Micro Cutting
,”
Int. J. Mach. Tools Manuf.
,
45
(
4–5
), pp.
529
535
.10.1016/j.ijmachtools.2004.09.001
21.
Ikawa
,
N.
,
Shimada
,
S.
,
Tanaka
,
H.
, and
Ohmori
,
G.
,
1991
, “
An Atomistic Analysis of Nanometric Chip Removal as Affected by Tool-Work Interaction in Diamond Turning
,”
CIRP Ann. Manuf. Technol.
,
40
(
1
), pp.
551
554
.10.1016/S0007-8506(07)62051-4
22.
Weule
,
H.
,
Huntrup
,
V.
, and
Tritschler
,
H.
,
2001
, “
Micro-Cutting of Steel to Meet New Requirements in Miniaturization
,”
CIRP Ann. Manuf. Technol.
,
50
(
1
), pp.
61
64
.10.1016/S0007-8506(07)62071-X
23.
Vogler
,
M. P.
,
DeVor
,
R. E.
, and
Kapoor
,
S. G.
,
2004
, “
On the Modeling and Analysis of Machining Performance in Micro-Endmilling, Part I: Surface Generation
,”
ASME J. Manuf. Sci. Eng.
,
126
(
4
), pp.
685
694
.10.1115/1.1813470
24.
Woon
,
K. S.
,
Rahman
,
M.
,
Neo
,
K. S.
, and
Liu
,
K.
,
2008
, “
The Effect of Tool Edge Radius on the Contact Phenomenon of Tool-Based Micromachining
,”
Int. J. Mach. Tool. Manuf.
,
48
(
12–13
), pp.
1395
1407
.10.1016/j.ijmachtools.2008.05.001
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