Wear - Stages of Wear

Stages of Wear

Under normal mechanical and practical procedures, the wear-rate normally changes through three different stages(ref.4):

  • Primary stage or early run-in period, where surfaces adapt to each other and the wear-rate might vary between high and low.
  • Secondary stage or mid-age process, where a steady rate of ageing is in motion. Most of the components operational life is comprised in this stage.
  • Tertiary stage or old-age period, where the components are subjected to rapid failure due to a high rate of ageing.

The secondary stage is shortened with increasing severity of environmental conditions such as higher temperatures, strain rates, stress and sliding velocities etc.
In explicit wear tests simulating industrial conditions between metallic surfaces, there are no clear chronological distinction between different wear-stages due to big overlaps and symbiotic relations between various friction mechanisms. Surface engineering and treatments are used to minimize wear and extend the components working life.

Read more about this topic:  Wear

Famous quotes containing the words stages of, wear and/or stages:

    The playing adult steps sideward into another reality; the playing child advances forward to new stages of mastery....Child’s play is the infantile form of the human ability to deal with experience by creating model situations and to master reality by experiment and planning.
    Erik H. Erikson (20th century)

    Don’t order any black things. Rejoice in his memory; and be radiant: leave grief to the children. Wear violet and purple.... Be patient with the poor people who will snivel: they don’t know; and they think they will live for ever, which makes death a division instead of a bond.
    George Bernard Shaw (1856–1950)

    Phlebas the Phoenician, a fortnight dead,
    Forgot the cry of gulls, and the deep sea swell
    And the profit and loss.
    A current under sea
    Picked his bones in whispers. As he rose and fell
    He passed the stages of his age and youth
    Entering the whirlpool.
    —T.S. (Thomas Stearns)