Inconel 718 is one of the most commonly used nickelbased alloys in aerospace industry. It is known to be among
the most difficult-to-cut materials due to its high strength even
at high temperatures, low thermal conductivity, and especially
rapid work hardening. Tool wear is an unavoidable and
complicated phenomenon occurring in machining process. It is
of great interests to machining industry to investigate the
inherent relationship among tool flank wear, surface integrity,
and fatigue performance of machined components.
In this research, the effects of tool flank wear on surface
integrity and fatigue life of components by end milling of
Inconel 718 was studied. The variation of surface integrity at
different levels of tool flank wear and diverse combinations of
process parameters was investigated. Tool wear values were
measured and determined by an on-line optical tool inspection
and measurement system. Surface integrity was characterized
and four-point bending fatigue testing was used to determine
the fatigue life of milled Inconel 718 specimens. By
correlating tool flank wear, surface integrity, and fatigue
performance of the machined components, a process space
with acceptable tool flank wear can be determined for
designed fatigue life with controlled variance.