Materials selection for a finite life time

Classical methods for materials selection only poorly account for the need of incorporating time into the design requirements. Corrosion, fatigue, wear and creep are phenomena that can lead to an accumulation of damage with time, ultimately causing failure. The first step in dealing with this is an evaluation of the potential risk for delayed damage followed by a qualitative ranking of the possible candidates. Beyond this point, both quantitative estimates and design rules have to be used to make the appropriate selection. Examples involving corrosion and creep will illustrate the possibility of and the need for under the form of.