ABSTRACT
Many mechanical components have life limits in their service due to the deterioration of their durability over time. These limitations are either explicitly defined by mandating the replacement of the part within a defined amount of time, or implicitly defined by the need for periodic inspections in accordance with the maintenance manual. Although it is more technically challenging to reverse engineer a life-limited part, market demands and higher profit margins provide strong incentives for their reproduction using reverse engineering. The life cycle of a part is determined either by the total load cycles the part has experienced or by the total time period the part has been placed in service. For example, a jet engine turbine disk usually needs to be replaced after a certain number of cycles or hours. This life limitation is because certain material properties, and therefore the performance of the part made of this material, are time dependent. This chapter will focus on the following three material properties that can affect part performance throughout time and impose life limitations on a part: fatigue, creep, and corrosion.
