Fundamentals of the Deep Rolling of Compressor Blades for Turbo Aircraft Engines

Abstract

The weakening of the fatigue strength of turbine blades due to local impact damage caused by foreign objects (Foreign Object Damage ‐ FOD) represents a significant safety risk in modern civil and military aviation. It is possible to employ deep rolling to counteract such component weakening in a particularly effective way. Although deep rolling has long been used on rotationally symmetric components, the underlying deformation processes are largely unknown. The deep rolling of thin‐walled free‐form surfaces, such as those on turbine blades, represents a new, demanding production challenge. For this reason, this paper describes the implementation of a deep‐rolling process for machining thin‐walled turbine blades and, by combining practical and numerical test results, outlines some of the underlying deformation processes.

Development of Combined Manufacturing Technologies for High-Strength Structural Components

“…Thus, surface near compressive residual stresses are created, which increase fatigue strength, reduce crack propagation and improve wear resistance [8]. Similar effects are found due to deep rolling of Ti6Al4V [9]. This indicates that an overlapping of rolling tracks allows the creation of planar compressive residual stresses in the subsurface of the workpiece.…”

“…In steel machining process steps for subsurface improvement are added, like deep rolling, finish rolling or shot peening [6,7]. Thus, surface near compressive residual stresses are created, which increase fatigue strength, reduce crack propagation and improve wear resistance [8]. Similar effects are found due to deep rolling of Ti6Al4V [9].…”

An overlapping domain decomposition method for the simulation of elastoplastic incremental forming processes

“…Deep rolling of turbine blades [1], see Figure 1, is a recently introduced forming technique, using simple shaped, small and flexible tools. This process is employed to counteract the weakening of fatigue strength by treating the surface of the component in such a way that hardening and residual compressive stresses are introduced.…”

Analytic roughness prediction by deep rolling

“…According to Klocke and Mader [4], the overlap factor u has a high influence on different surface values. The overlap u is a unitless factor, which relates the feed f w to the contact radius.…”