Abstract:

The effects of contact pressure, amplitudes, applied loads, temperature, number of cycles and the ratio of high cycle load to low cycle one on fretting fatigue life and frictional coefficient were carried out. The test results indicate that both the tensile stress and the contact pressure affect the FFL. The difference between the PFL and FFL is not obvious for large tensile stresses and so does the effect of the contact pressure on the FFL. For small tensile stresses FFL is reduced greatly and the contact pressure affects the FFL heavily; it is reduced first with the increase of contact pressure at low contact pressure, but increases when the latter is greater than 200Mpa because of the decrease of amplitude. With the increase of temperature the FFL decreases from room temperature to 200℃, increases at about 300℃, and decreases again. The SEM studies reveal that it is flake like oxide that protects the contact surface from further damage and results in an enhancement of FFL.

Key words: fret t ing fat igue, comp lex load, stainless steel, t itanium alloy