Choosing the proper metal forming lubricant for nonferrous metals such as aluminum, copper, and brass has become a difficult and complicated decision. The effects of deformation velocity and the influence of deforming material were determined in the two sets of experiments carried out using a single punch with a roughness magnitude Ra of 0.17 μm and four lubricants such as grease, corn oil, VG100, and VG32. In the first set, two different deformation speeds of 0.1 and 1 mm/s were used for cylindrical specimens made of aluminum alloys of 6061-O, 1050-O, and copper alloys tests using a counterpunch die of roughness magnitude Ra of 0.08 μm. In the second set of experiments, cylindrical specimens made of aluminum alloys of AA2024-O and AA6061-O and three deformation speeds of 0.1, 1, and 5 mm/s were used to evaluate the performance of each lubricant under increasing ram speed, but with a roughness magnitude Ra of 0.63 μm. All the lubricants show reduction in maximum load with increasing deformation speed except grease which shows a rise in the maximum load from zero to a maximum at a deformation speed of 1 mm/s and then descends gradually to a minimum load at a speed of 5 mm/s for AA2024-O and AA6061-O. This load reduction seen with grease as lubricant is probably due to thermal softening; therefore grease will not be considered a desirable lubricant under increasing deformation speed because of the adverse effects on the tooling. The present findings show that tip test can be utilized to select an appropriate lubricant for a particular alloy. It reveals that none of the tested lubricants can be used for copper alloy as all the lubricants show increasing measured load for increasing speed magnitude. However, of the liquid lubricants (corn oil, VG100, and VG32) considered, corn oil shows as the best lubricant for cold forging operations of aluminum 6061-O, 1050-O, and 2024-0 under increasing speed magnitude. Also, the tip test has been able to differentiate among materials.

References

References
1.
Schrader
,
T.
,
Shirgaokar
,
M.
, and
Altan
,
T.
, 2007, “
A Critical Evaluation of the Double Cup Extrusion Test for Selection of Cold Forging Lubricants
,”
J. Mater. Proc. Technol.
,
189
, pp.
36
44
.
2.
Schikorra
,
M.
,
Donati
,
L.
,
Tomesani
,
L.
, and
Kleiner
,
M.
, 2007, “
The Role of Friction in the Extrusion of AA6060 Aluminum Alloy, Process Analysis and Monitoring
,”
J. Mater. Proc. Technol.
,
191
, pp.
288
292
.
3.
Ghobrial
,
M. I.
,
Lee
,
J. Y.
,
Altan
,
T.
,
Bay
,
N.
, and
Hansen
,
B. G.
, 1993, “
Factors Affecting the Double Cup Extrusion Test for Evaluation of Friction in Cold and Warm Forging
,”
Ann. CIRP
,
42
(
1
), pp.
347
351
.
4.
Vigso
,
C.
,
Kim
,
H.
,
Sweeney
,
K.
,
Shen
,
G.
, and
Altan
,
T.
, 1994, “Evaluation of Friction in Cold Forging by the Single/Double Cup Extrusion Test,” Report (ERC/NSM-B-94-59), The Ohio State University.
5.
Im
,
Y. T.
,
Cheon
,
J. S.
, and
Kang
,
S.-H.
, 2002, “
Determination of Friction Condition by Geometrical Measurement of Backward Extruded Aluminum Alloy Specimen
,”
ASME J. Manuf. Sci. Eng.
,
124
, pp.
409
415
.
6.
Im
,
Y. T.
,
Jung
,
K.-H.
,
Lee
,
H -C.
,
Ajiboye
,
J. S.
, and
Kang
,
S.-H.
, 2009, “
Measurement of the Effect of Surface Topology on Friction by Tip Test
,” Proc. of the ASME 2009 Inter. Manuf. Sci. and Eng. Conf. October 4–7, West Lafayette, IN, pp.
1
9
.
7.
Jung
,
K.-H.
,
Lee
,
H.-C.
,
Ajiboye
,
J. S.
,
Kang
,
S.-H.
, and
Im
,
Y. T.
, 2009, “
The Effect of Surface Conditions on Friction by Tip Test
,”
ASME J. Tribol.
,
132
, p.
011601
.
8.
Jung
,
K.-H.
, and
Im
,
Y. T.
, 2010, “
The Effect of Deformation Speed on Frictional Behavior by Tip Test
,”
ASME J. Tribol.
,
132
(
3
), pp.
1
6
.
9.
Sims
,
R. B.
, and
Arthur
,
D. F.
, 1952, “
Speed Dependent Variables in Cold Strip Rolling
,”
J. Iron Steel Inst.
,
172
, pp.
285
295
.
10.
Cann
,
P. M.
, 1997, “
Grease Lubricant Film Distribution in Rolling Contacts
,”
NLGI Spokesman
,
61
(
2
), pp.
22
29
.
11.
Wallace
,
P. W.
, and
Schey
,
J. A.
, 1971, “
Speed Effects in Forging Lubrication
,”
J. Lubrication Technol., Ser. F
,
93
(
3
), pp.
317
323
.
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