Journal of Materials Research


The frictional component of the indentation size effect in low load microhardness testing

H. Lia1 p1, A. Ghosha1 p2, Y.H. Hana1 and R.C. Bradta1

a1 Mackay School of Mines, University of Nevada, Reno, Nevada 89557-0136


The role of friction between the microhardness indenter and the test specimen is addressed through the analysis of dry (unlubricated) and lubricated tests on iron by Atkinson and Shi. Quantitative evaluation through a proportional specimen resistance model accurately describes the results. It suggests that friction is a major portion of the observed hardness increase at low test loads, the indentation size effect. The ISE is related to the surface-area-to-volume ratio of the indentation, which is inversely related to the indentation dimension.

(Received June 15 1992)

(Accepted December 20 1992)


p1 Present address: Department of Materials Engineering, Materials Research Center, Rensselaer Polytechnic Institute, Troy, New York 12180-3590.

p2 Present address: Southwest Research Institute, San Antonio, Texas 78228.