Inspection of 1100-H14 and 5052-0 aluminum alloy surfaces deformed in tension, sheet forming, and rolling with a thick lubricant film indicated that similar mechanisms were involved in the roughening process. The predominant mechanism was associated with the orientation of slip systems in adjacent grains leading to mismatch strains at the grain boundaries. The emergence of slip planes played a lesser role in the roughening process. A roughening model that assumed a spatial hardness variation was developed. Theoretical predictions of the dependence of the Ra surface roughness with bulk strain, based on micro-hardness measurements, show excellent agreement with experiment.

Issue Section:
Technical Papers
Keywords:
forming processes, rough surfaces, aluminium alloys, slip, microhardness, surface topography
Topics:
Aluminum alloys, Metalworking, Microhardness, Surface roughness, Lubricants, Tension, Grain boundaries, Deformation
1.
Yamaguchi
,
K.
, and
Mellor
,
P. B.
,
1976
, “
Thickness and Grain Size Dependence of Limit Strains in Sheet Metal Stretching
,”
Int. J. Mech. Sci.
,
18
, pp.
85
–
90
.
2.
Saha
,
P. K.
, and
Wilson
,
W. R. D.
,
1994
, “
Influence of Plastic Strain on Friction in Sheet Metal Forming
,”
Wear
,
172
, pp.
167
–
173
.
3.
Wilson, W. R. D., and Farrell, W. J., 1976, “Lubricant Transport and Breakdown in a High Speed Forging Operation,” Proc. NAMRC IV (SME), pp. 130–137.
4.
Osakada
,
K.
, and
Oyane
,
M.
,
1971
, “
On the Roughening of Free Surface in Deformation processes
,”
Bull. JSME
,
14
, pp.
171
–
177
.
5.
Tokizawa
,
M.
, and
Yosikawa
,
Y.
,
1973
, “
The Mechanism of Lubricant Trapping under the Cold Compression of Metals
,”
J. Jpn. Inst. Met.
,
37
, pp.
19
–
25
.
6.
Chen
,
G.
,
Shen
,
H.
,
Hu
,
S.
, and
Baudelet
,
B.
,
1990
, “
Roughening of the Free Surfaces of Metallic Sheets during Stretch Forming
,”
Mat. Sci. Eng.
,
A128
, pp.
33
–
38
.
7.
Ratnagar
,
D. D.
,
Cheng
,
H. S.
, and
Schey
,
J. A.
,
1974
, “
The Surface Deformation of Aluminum Compressed With Viscous Lubricants
,”
J. Lubr. Technol.
,
96
, pp.
591
–
594
.
8.
Wilson
,
W. R. D.
,
1977
, “
Workpiece Surface Roughening in a Hydrodynamically Lubricated Metal Forming Process
,”
J. Lubr. Technol.
,
99
, pp.
10
–
14
.
9.
Wilson, W. R. D., and Siletto, J. G., 1980, “Surface Roughening in Liquid Lubricated Upsetting,” Metalworking Lubrication, ASME, New York, pp. 87–94.
10.
Wilson, W. R. D., and Schmid, S., 1992, “Surfaces in Metal Rolling,” PED-Vol 62., Engineered Surfaces., Ehmann K. F., and Wilson, W. R. D., eds., ASME, New York, pp. 91–100.
11.
Saha, P. K., Shih, H-C., and Wilson, W. R. D., 1996, “Modeling the Influence of Plastic Strain on Boundary Friction In Sheet Metal Forming,” NAMRI Trans. (SME), pp. 173–180.
12.
Wilson, W. R. D., Malkani, H. G., and Saha, P. K., 1991, “Boundary Friction Measurements Using a New Sheet Metal Forming Simulator,” Proc. NAMRC XIX (SME), pp. 37–42.
13.
Lee, W., 1996, “Surface Roughening in Metal Forming Processes,” Ph.D. Thesis, Mechanical Engineering, Northwestern University, Evanston, IL.
14.
Wilson, W. R. D., and Sheu, S., 1983, “Flattening of Workpice Surface Asperities in Metalforming,” Proc. NAMRC XI (SME), pp. 172–178.
15.
Wilson
,
W. R. D.
, and
Sheu
,
S.
,
1988
, “
Real Area of Contact and Boundary Friction in Metal Forming
,”
Int. J. Mech. Sci.
,
30
, No.
7
, pp.
475
–
489
.
Copyright © 2001
 by ASME
You do not currently have access to this content.