STP889

    Measurement of Hardness at Indentation Depths as Low as 20 Nanometres

    Published: Jan 1985


      Format Pages Price  
    PDF Version (424K) 19 $25   ADD TO CART
    Complete Source PDF (4.9M) 19 $55   ADD TO CART


    Abstract

    Hardness as a function of depth is examined over a wide range of depths in gold, nickel, lithium fluoride (LiF), and silicon. To examine hardness in very shallow indents (100 nm), a special hardness tester with 2.5-μN load resolution and 0.2-nm indenter displacement resolution was used. The tester monitors the load continuously as the load is applied and removed. The hardness is calculated using the depth measurements. Images of indents in the scanning electron microscope (SEM) and transmission electron microscope (TEM) are used to check that the expected contact areas are achieved. It is shown that the contact area can be calculated if elastic effects are accounted for. The loading and unloading portions of the curves are discussed in detail. Attention is paid to the mechanisms of hardness changes with depth and the effects of elastic recovery on contact area measurement.

    Keywords:

    microhardness, surfaces, mechanical properties, elastic recovery, gold, nickel, lithium fluoride, silicon, microindentation, hardness testing


    Author Information:

    Oliver, WC
    Research scientist, Oak Ridge National Laboratory, Oak Ridge, TN

    Hutchings, R
    Staff member, University of Cape Town, Cape Town,

    Pethica, JB
    Staff member, Cavendish Laboratory, University of Cambridge, Cambridge,


    Paper ID: STP32953S

    Committee/Subcommittee: E04.05

    DOI: 10.1520/STP32953S


    CrossRef ASTM International is a member of CrossRef.