Design of engineering components is concerned with their strength and durability characteristics. While design for strength is influenced by the bulk material characteristics, the design for durability is dependant on the surface characteristics. Majority of the component failures are surface originated. Surface engineering could play a vital role in minimizing such failures. Thermal sprayed coatings, one of the versatile surface coating techniques, can be applied to components of machinery surfaces to avoid such failures. The present paper presents a methodology for contact stress evaluation of surface coated elements, adopting a layered structure approach, and thereby analytically predict their spalling life. Further data on cycles to single pit formation, and spalling of spray fused coatings obtained from experimental testing are presented for assessing the applicability of life prediction models to layered structures such as sprayed coatings. Experimental investigations were conducted on spray fused coatings using a twin disk RCF test setup. The surface and subsurface contact stress distribution have been obtained analytically by Smith–Liu equations along with first order model perturbation method (FOMP), to account for the variation of elastic modulus constants of the layered structure. Applying Lundberg-Palmgren and Tallian life prediction models, the spalling life of these coatings has been predicted analytically and compared with experimental life values. [S0742-4787(00)02502-9]

1.
Hannah
,
M.
,
1951
, “
Contact Stress Determination in a Thin Elastic Layer
,”
Q. J. Mech. Appl. Math.
,
4
, pp.
94
105
.
2.
Pao
,
Y. C.
,
Wu
,
T. S.
, and
Chiu
,
Y. P.
,
1971
, “
Bounds on Maximum Contact Stress of an Indented Elastic layer
,”
ASME J. Appl. Mech.
,
38
, p.
608
608
.
3.
Gupta, P. K., Walowit, J. A., and Finkin, E. F., 1973, “Stress Distributions in Plane Strain Layered Elastic Solids Subjected to Arbitrary Boundary Loading,” ASME J. Lubr. Technol., pp. 427–433.
4.
Komvopoulos
,
K.
,
1989
, “
Elastic-Plastic Finite Element Analysis of Indented Layered Media
,”
ASME J. Tribol.
,
111
, pp.
430
439
.
5.
Komvopoulos
,
K.
,
1988
, “
Finite Element Analysis of a Layered Elastic Solid in Normal Contact With a Rigid Surface
,”
ASME J. Tribol.
,
110
, pp.
477
485
.
6.
Ahn
,
H. S.
, and
Roylance
,
B. J.
,
1990
, “
Stress Behavior of Surface-Coated Materials in Concentrated Sliding Contact
Surf. Coat. Technol.
,
41
, pp.
1
15
.
7.
Cole
,
S. J.
, and
Sayles
,
R. S.
,
1992
, “
A Numerical Model For the Contact of Elastic Bodies With Real Rough Surfaces
,”
ASME J. Tribol.
,
114
, pp.
334
340
.
8.
Elsharkawy
,
A. A.
, and
Hamrock
,
B. J.
,
1993
, “
A Numerical Solution for Dry Sliding Line Contact of Multilayered Elastic Bodies
,”
ASME J. Tribol.
,
115
, pp.
237
245
.
9.
Tobe S., Kodama, S., Sekiguchi, K., 1988 “Rolling Fatigue Behavior of Plasma Coated Steel,” Proceedings of Surface Engineering International Conference, Japan Thermal Spray Society, Tokyo, Japan, pp. 35–44.
10.
Hadfield
,
M.
,
Tobe
,
S.
, and
Stolarski
,
T.
,
1994
, “
Subsurface Crack Investigation on Delaminated Ceramic Elements
,”
Tribol. Int.
,
27
, No.
5
, pp.
359
367
.
11.
Hadfield
,
M.
, and
Stolarski
,
T.
,
1995
, “
The Effect of the Test Machine on the Failure Mode in Lubricated Rolling Contact of Silicon Nitride
,”
Tribol. Int.
,
28
, No.
6
, pp.
377
382
.
12.
He, J. W-., Hendrix, B. C., Hu, N. S., Xu, K.-W., Bell, T., Sun, Y., and Mao, K., 1996, “Interfacial Fatigue Limit As Measure of Cyclic Bonding Strength of Hard Coat,” Surf. Eng., No. 1, pp. 49–54.
13.
Ahmed
,
R.
, and
Hadfield
,
M.
,
1997
, “
Rolling Contact Fatigue Performance of Detonation Gun Coated Elements
,”
Tribol. Int.
,
30
, No.
2
, pp.
129
137
.
14.
Smith
,
J. O.
, and
Liu
,
C. K.
,
1953
, “
Stresses Due to Tangential and Normal Loads on Elastic Solids with Application to Some Contact Stress Problem
,”
ASME J. Appl. Mech.
,
75
, pp.
157
166
.
15.
Huajian
,
Chiu
, and
Lee
,
Jin
,
1992
, “
Elastic Contact Versus Indentation Modelling of Multilayered Materials
,”
Int. J. Solids Struct.
,
29
, pp.
2471
2492
.
16.
Lundberg
,
G.
, and
Palmgren
,
A.
,
1947
, “
Dynamic Capacity of Roller Bearings
,”
Acta Polytechnica 7, Mech. Engg. Series
,
2
, No. 3, Stockholm, Sweden.
17.
Tallian
,
T. E.
,
1992
, “
Simplified Contact Fatigue Life Prediction Model - Part II: New Model
,”
ASME J. Tribol.
,
114
, pp.
214
222
.
18.
Dowson, D., and Higginson, G. R., 1977, ElastoHydrodynamic Lubrication, Pergamon Press, Oxford.
19.
Sarma, B. Y., 1997 “Some studies on life prediction of Thermal Sprayed Coatings under rolling contact condition” M.S., thesis, Department of Mechanical Engineering, Indian Institute of Technology, Madras.
20.
Johnson, K. L., and Jefferis, J. A., 1963 “Plastic Flow and Residual Stresses in Rolling and Sliding Contact,” Proc. Institution of Mechanical Engineering Symposium on Rolling Contact Fatigue, London, p. 50.
You do not currently have access to this content.