Fretting wear rate evolution of a flat-on-flat low alloyed steel contact: A weighted friction energy formulation

Abstract

Fretting wear resulting from micro-displacement oscillatory movements is considered a serious impediment to many industrial applications like gears, turbo engines, etc. Large conformal contact configurations of industrial components are very complicated to reproduce at laboratory scale. As a result, simple non-conformal contact geometries including sphere-on-flat and cylinder-on-flat are usually adopted in research laboratories. Yet, few are the researches that examined fretting wear using flat-on-flat geometry due to its high sensitivity to alignment issues although this contact configuration allows the analysis of quasi-constant pressure condition. In the current study, fretting wear of flat-on-flat dry contact made of a steel alloy (35NCD16) is investigated experimentally by varying several parameters including test duration, contact pressure, sliding amplitude and frequency. A power law formulation is introduced providing reliable prediction of the wear rate. The analysis of test results confirms a high dependency of the wear kinetics on the loading condition regarding the transition from abrasive to adhesive wear.

Modelling adhesive wear extension in fretting interfaces: An advection-dispersion-reaction contact oxygenation approach

“…MPa, sliding amplitude δ g =±100 µm, and the apparent contact area A=25 mm². Note that the number of fretting cycles was fixed at 20000 cycles to achieve the steady state friction regime which is reached after 5000 fretting cycles [37]. Former investigations [14] confirmed insignificant changes regarding the partition between abrasive and adhesive wear areas between 5000 to 40000 cycles.…”

“…Fretting tests were performed on a homogeneous 34NiCrMo16 interface. This low steel alloy was previously investigated in [14,37]. The mechanical properties and the chemical composition of 34NiCrMo16 are displayed in Table 2.…”

“…5b) which is highly adapted to examine large horizontal crossed flat configurations. More detailed description of the test setup is provided elsewhere [14,37]. The fretted surface is rectangular in shape exhibiting a nominal contact area " ".…”

“…A major interest of this flat-on-flat interface compared to the usual Hertzian configuration is the possibility to keep constant the apparent contact area whatever the surface wear extension. Besides, former FEM surface wear simulations suggest that the contact pressure profile converges to a flat mean contact pressure distribution after few hundred cycles allowing a direct correlation with the given ADR model [37]. Three frequencies (f=0.5, 1, & 10 Hz) are investigated to calibrate the model while keeping constant the fretting cycles N=20000 cycles, contact pressure p=100…”

Explicit formulations of adhesive wear extension in fretting interfaces applying the contact oxygenation concept

“…A hydraulic test machine, specific for testing large flat contacts (see Ref. [12,18]) is used to perform the experiments.…”