Effect of dissimilar metals on fretting fatigue behavior of Ti-6Al-4V

An investigation was conducted to explore fretting fatigue behavior of Ti-6Al-4V specimens in contact with pads of varying composition. Four conditions were selected to provide a range of compositions: Ti-6Al-4V (with two surface finishes), aluminum and nickel. Behavior against each pad condition was evaluated for two pad geometries (cylinder-on-flat, blended flat-on-flat) in two separate test fixtures. Experiments were conducted with varying applied fatigue stresses and contact forces. Applied clamping stresses for the flat-on-flat pads were similar to 200 and similar to 650 MPa. For the cylinder-on-flat geometry, forces were selected to provide Hertzian peak pressures of 292 and 441 MPa. The coefficient of friction, mu, was quantified and pad surfaces were characterized through hardness and composition evaluation. Finite element analyses of the test fixtures were conducted to assess variations in the stress fields. (c) 2006 Elsevier Ltd. All rights reserved.