Journal of Materials Science and Engineering with Advanced TechnologyAuthor's: S. Mall, E. Madhi and H.-K. Kim
Pages: [1] - [27]
Received Date: July 21, 2010
Submitted by:
Fretting fatigue behaviour of a nickel based alloy, IN100, was investigated at room temperature. Fretting fatigue tests were conducted at various stress levels by using two cylindrical pad geometries. Fretting fatigue crack initiation location and orientation angle were documented. Fretting reduced the strength/life in comparison to those in the plain fatigue; however, this reduction was relatively less than that in titanium alloy, Ti-6Al-4V. Both IN100 and Ti-6Al-4V are used in gas turbine engines. Increase in cylindrical pad radius had relatively less detrimental effect on the fretting fatigue life/strength of IN100 relative to those of titanium alloy, Ti-6Al-4V. The primary fretting fatigue crack initiated near the trailing edge on the contact surface, and at an orientation of 45° with a variation of ±10°. Finite element analysis was also conducted to obtain the stress state in the contact region, which was then used to compute a critical plane based parameter, modified shear stress range parameter, involving both normal and shear stresses on the critical plane. This parameter was found to be capable of predicting crack location, crack initiation angle and correlating the fretting fatigue lives of two contact geometries and plain fatigue lives on a single curve.
fretting, fatigue, IN100, critical plane parameter, contact mechanics.
