Nickel Alloy Machining Techniques

A continuous challenge in the aerospace manufacturing industry is the machining of nickel-based super alloys such as Inconel in a cost effective and precise manner.  Inconel carries a 12% machinability rating per the AISI Machinability Index.  More commonly machined materials such as Aluminum or Steel boast machinability ratings of 360% and 66% respectively.  Additionally, aerospace components are produced at relatively low annual volumes.  This does not always permit a net shape casting to be made which results in machining parts from solid bar stock or plate.  Determining a way to efficiently machine Inconel is critical to success in the aerospace machining industry.

Solving this problem required hours of testing and development of different cutting tool geometries, coatings, and carbide grades as well as refining the machining processes and cutting parameters (speed and feed).  This required working with cutting tool suppliers from across the USA to test newly designed cutting tools in a controlled state.  Our Engineering Department measured tool life, spindle load, axis load, and part quality. The resulting solution is a combination of well-developed cutting tools and the utilization of a machining process called Chip Thinning.

The outcome from our designed experiment resulted in improved tool life and cycle time.  Specifically we were able to increase our material removal rate from 1.1 in³ per minute to 8.0 in³ per minute without sacrificing part quality or tool life.  These continuous improvements efforts allow us to offer competitive, world-class solutions to our customers.