This paper aims to explain the size-effect in the Primary Deformation Zone (PDZ) in machining using strain gradient plasticity theory. Considering a parallel-sided shear zone configuration, models are formulated for the evaluation of strain gradient, density of geometrically necessary dislocations, shear strength and the specific shear energy. The analysis of deformation in the PDZ shows that the length of the shear plane represents the fundamental material length scale governing the size-effect. It also provides an estimate of the lower bound on the size-effect observed in the specific shear energy. The general trends predicted by the model are shown to agree well with the experimental values obtained from the literature.
Issue Section:
Technical Papers
1.
Ashby
, M. F.
, 1970
, “The Deformation of Plastically Non-Homogeneous Materials
,” Philos. Mag.
, 21
, pp. 399
–424
.2.
Fleck
, N. A.
, Muller
, G. M.
, Ashby
, M. F.
, and Hutchinson
, J. W.
, 1994
, “Strain Gradient Plasticity Theory and Experiment
,” Acta Metall. Mater.
, 42
(2
), pp. 475
–487
.3.
Ma
, Q.
, and Clarke
, D. R.
, 1995
, “Size Dependent Hardness of Silver Single Crystals
,” J. Mater. Res.
, 10
(4
), pp. 853
–863
.4.
Gao
, H.
, Huang
, Y.
, Nix
, W. D.
, and Hutchinson
, J. W.
, 1999
, “Mechanism Based Strain Gradient Plasticity—I Theory
,” J. Mech. Phys. Solids
, 47
, pp. 1239
–1263
.5.
Duan
, D. M.
, Wu
, N. Q.
, Slaughter
, W. S.
, and Mao
, S. X.
, 2001
, “Length Scale Effect in Mechanical Behavior due to Strain Gradient Plasticity
,” Mater. Sci. Eng., A
, 303
, pp. 241
–249
.6.
Usui
, E.
, Gujral
, A.
, and Shaw
, M. C.
, 1961
, “An Experimental Study of the Action of CCl4 in Cutting and Other Processes Involving Plastic Flow
,” Int. J. Mach. Tool Des. Res.
, 1
, pp. 187
–197
.7.
Walker, T. J., and Shaw, M. C., (1969), “On Deformation at Large Strains,” Proc. Of 10th IMTDR Conference, pp. 241–252.
8.
Shaw
, M. C.
, 1980
, “A New Mechanism of Plastic Flow
,” Int. J. Mech. Sci.
, 22
(11
), pp. 673
–686
.9.
Shaw, M. C., 1983, Metal Cutting Principles, Oxford University Press, pp. 194–195.
10.
Vyas
, A.
and Shaw
, M. C.
, 1999
, “Mechanics of Saw-Tooth Chip Formation in Metal Cutting
,” ASME J. Manuf. Sci. Eng.
, 121
(2
), pp. 163
–172
.11.
Backer
, W. R.
, Marshall
, E. R.
, and Shaw
, M. C.
, 1952
, “The Size Effect in Metal Cutting
,” Trans. ASME
, 74
, p. 62
62
.12.
Nakayama
, K.
, and Tamura
, K.
, 1968
, “Size Effect in Metal Cutting Force
,” ASME J. Eng. Ind.
90
(1
), pp. 119
–126
.13.
Boothroyd, G., and Knight, W. A., 1989, Fundamentals of Metal Machining and Machine Tools, Marcel Dekker, Inc. NY.
14.
Larson-Basse, J., and Oxley, P. L. B., 1973, “Effect of Strain Rate Sensitivity on Scale Phenomenon in Chip Formation,” Proc. Of 13th Int. Mach. Tool Des. Res. Conference, pp. 209–216.
15.
Dinesh, D., Swaminathan, S., Chandrasekar, S., and Farris, T. N., 2001, “An Intrinsic Size Effect in Machining due to the Strain Gradient,” Proc. of ASME IMECE, Nov 11–16, NY, USA, CD-ROM Proc., pp. 1–8.
16.
Van Luttervelt
, C. A.
, Delft
, T. U.
, Childs
, T. H. C.
, Jawahir
, I. S.
, Klocke
, F.
, and Venuvinod
, P. K.
, 1998
, “Present Situation and Future Trends in Modeling of Machining Operations
,” CIRP Ann.
, 47
(2
), pp. 587
–626
.17.
Oxley, P. L. B., and Welsh, M. J. M., 1963, “Calculating Shear Angle in Orthogonal Metal Cutting From Fundamental Stress, Strain and Strain-Rate Properties of the Work Material,” Proc. of 4th Int. Mach. Tool Des. Res. Conf., pp. 73–86.
18.
Stevenson
, M. G.
, and Oxley
, P. L. B.
, 1969
–70, “An Experimental Investigation of the Influence of Speed and Scale on the Strain-Rate in Zone of Intense Plastic Deformation
,” Proc. Inst. Mech. Eng.
, 184
, pp. 561
–576
.19.
Arsenlis
, A.
, and Parks
, D. M.
, 1999
, “Crystallographic Aspects of Geometrically-Necessary and Statistically-Stored Dislocation Density
,” Acta Mater.
, 47
(5
), pp. 1597
–1611
.20.
Merchant
, M. E.
, 1945
, “Mechanics of the Metal Cutting Process
,” J. Appl. Phys.
, 16
(5
), p. 267, and No. 6, p. 318
267, and No. 6, p. 318
.21.
Properties and Selection: Non-Ferrous Alloys and Special Purpose Materials, ASM Metals Handbook, 1990, Vol. II, pp. 304–305.
22.
Fleck, N. A., and Hutchinson, J. W., 1997, “Strain Gradient Plasticity,” Advances in Applied Mechanics, Hutchinson, J. W. and Wu, T. Y., eds., Vol. 33, Academic Press, New York, p. 295.
23.
Dieter, G. E., 1976, Mechanical Metallurgy, McGraw Hill Inc.
Copyright © 2004
by ASME
You do not currently have access to this content.
