Abstract
The type of lubrication regime which occurs in a metal forming operation has a strong influence on the frictional conditions as well as on other important factors such as product surf ace finish and tooling wear rate. The characteristics of the different types of regimes which can occur are reviewed, together with what is known about their incidence in drawing, extrusion, rolling, and upsetting operations. In the light of this information it is evident that the commonly used methods of characterizing friction can often lead to erroneous results. Suggestions for improved methods of characterizing friction are made.
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Abbreviations
- A:
-
−66.1 exp (0.019445), semi-empirical function
- B:
-
1.05 + (4.32/s), semi-empirical function
- Cr :
-
roughness correction factor
- Ct :
-
thermal correction factor
- C1C2 :
-
arbitrary constants
- G:
-
γσ, non-dimensional pressure coefficient of viscosity
- H:
-
h 0/ha, non-dimensional entrained film thickness
- L:
-
μ 0αŪ2/k, viscous thermal parameter
- L*:
-
\(\mu _0 \alpha \bar U^2 /k\) viscous thermal parameter
- R:
-
r/h 0, non-dimensional roughness
- S:
-
ratio of workpiece strength to lubricant strength
- T:
-
temperature
- T0 :
-
surface temperature
- Ū:
-
mean surface speed
- U1 :
-
inlet workpiece speed
- V:
-
die approach speed
- a:
-
roll radius, fractional contact area
- b:
-
fraction of pressure carried by contact
- h:
-
local lubricant film thickness
- ha :
-
applied lubricant coating thickness
- h0 :
-
entrained or entrapped lubricant film thickness
- k:
-
lubricant thermal conductivity
- m:
-
t f/τw, friction factor
- p:
-
local pressure
- q:
-
extrusion pressure
- r:
-
RMS surface roughness, radius from axis of symmetry
- t:
-
time
- x:
-
distance along lubricant film
- x1 :
-
contact length, workpiece radius, workpiece half-width
- α:
-
lubricant temperature coefficient of viscosity
- β:
-
angle between roughness lay and rolling direction
- γ:
-
lubricant pressure coefficient of viscosity
- θ:
-
die semi-angle, angle of nip
- μ:
-
lubricant viscosity, coefficient of friction
- μ0 :
-
lubricant viscosity at zero pressure and surface temperature
- μb :
-
coefficient of function in boundary regime
- μ1 :
-
coefficient of function in thick film regime
- σ:
-
workpiece flow strength
- τf :
-
friction stress
- τw :
-
workpiece shear strength
- ϕ:
-
redundant work factor
References
W. R. D. Wilson:Int. J. Mech. Sci., 1971, vol. 13, pp. 17–28.
R. W. Snidle, B. Parsons, and D. Dowson:Elastohydrodynamic lubrication-1972 Symposium, pp. 107–18, Inst. Mech. Eng., London, 1972.
A. Eichinger and W. Lueg:Mitt Kaiser Wilhelm Inst fur Eisenforschung, 1941, vol. 23, pp. 21–30.
Y. H. Tsao and L. B. Sargent:Trans. ASLE, 1978, vol. 21, pp. 20–26.
W. R. D. Wilson and J. A. Walowit:J. Lub. Technol., 1971, vol. 93, pp. 69–74.
W.R.D. Wilson and J.A. Walowit:Tribology Convention-1971, pp. 169–72, Inst. Mech. Eng., London, 1972.
W.R.D. Wilson:J. Lub. Technol., 1971, vol. 93, pp. 75–78.
W. R. D. Wilson and L. E. Murch:J. Lub. Technol., 1976, vol. 98, pp. 426–32.
W. R. D. Wilson and S. M. Mahdavian:J. Lub. Technol., 1976, vol. 98, pp. 27–31.
W. R. D. Wilson and B. B. Aggarwal:Wear, 1978, vol. 47, pp. 119–32.
L.B. Sargent and Y.H. Tsao:Joint Lubrication Conference 1978, presented at A.S.L.E.-A.S.M.E. and to be published inTrans. ASLE.
W. R. D. Wilson and K. Halliday:Wear, 1977, vol. 42, pp. 135–48.
K. Halliday and W.R.D. Wilson:Proc. NAMRC V, pp. 165–70, S.M.E., Detroit, 1977.
W. R. D. Wilson:Proceedings First Int. Conf. on Lubrication Challenges, IITRI, Chicago, 1978.
D. R. White and W. R. D. Wilson: “Solid lubricant entrainment in hydrostatic extrusion,” submitted toTrans. ASLE.
M. Oyane and K. Osakada:Bull. J.S.M.E., 1969, vol. 12, pp. 149–55.
W. R. D. Wilson:J. Lub. Technol., 1974, vol. 95, pp. 539–46.
W. R. D. Wilson and C. J. Wong:J. Lub. Technol., 1974, vol. 95, pp. 605–10.
W. R. D. Wilson and C. J. Wong:Proc. NAMRC III, pp. 168–78, Carnegie Press, Pittsburgh, 1975.
J. G. Silletto and W. R. D. Wilson: “Solid lubricant entrapment in an upsetting operation,” in preparation.
B. B. Aggarwal and W. R. D. Wilson: “Thermal effects in hydrodynamically lubricated strip rolling,” presented at 1978 Leeds-Lyons Symposium, to be published by Inst. Mech. Eng.
W. R. D. Wilson and W. B. Carpenter:Wear, 1973, vol. 24, pp. 351–60.
W. R. D. Wilson and E. A. Kokoska:Wear, 1975, vol. 32, pp. 25–32.
W. R. D. Wilson and W. P. Delmolino:Wear, 1974, vol. 25, pp. 1–10.
W. R. D. Wilson and W. J. Farrel:Proc. NAMRC IV, pp. 130–37, Battelle, Columbus, 1976.
W. R. D. Wilson and S. M. Mahdavian:Proc. NAMRC III, pp. 52–71, Carnegie Press, Pittsburgh, 1975.
W. R. D. Wilson and S. Lak:J. of Lub. Technol., 1977, vol. 99, pp. 230–35.
S. Lak and W.R.D. Wilson:Proc. 1977 Leeds-Lyons Symposium, Inst. Mech. Eng., London.
W. R. D. Wilson and P. Cazeault:Proc. NAMRC IV, pp. 165–70, Battelle, Columbus, 1976.
W. R. D. Wilson:J. Lub. Technol., 1973, vol. 95, pp. 541–43.
S. M. Mahdavian and W. R. D. Wilson:J. Lub. Technol., 1976, vol. 98, pp. 22–26.
R. W. Snidle, B. Parsons, and D. Dowson:J. Lub. Technol., 1976, vol. 98, pp. 335–43.
H. S. Cheng:Friction and Lubrication in Metal Processing, pp. 69–80, A.S.M.E., New York, 1966.
Y. H. Tsao and L. B. Sargent:Trans. ASLE, 1977, vol. 20, pp. 55–63.
W. R. D. Wilson and P. Cazeault:Proc. NAMRC IV, pp. 165–70, Battelle, Columbus, 1976.
W. R. D. Wilson:Proc. G.M. Symposium on Mechanics of Sheet Metal Forming, Plenum, New York.
N. Patir and H. S. Cheng: ASME Paper No. 78-LUB 17, to be published inJ. Lub. Technol.
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Wilson, W.R.D. Friction and lubrication in bulk metal-forming processes. J. Applied Metalworking 1, 7–19 (1978). https://doi.org/10.1007/BF02833955
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DOI: https://doi.org/10.1007/BF02833955