Aerospace, tight tolerances and titanium: it’s not rocket science

Titanium and its alloys are popular materials for the aerospace industry, because it is stronger than steel, has twice the elasticity and weighs half as much. However, despite its many beneficial properties, titanium is notoriously difficult to machine.

That’s because titanium is a poor thermal conductor, so heat intensifies at the cutting area, and dulls cutting tools. Using dull cutting edges can generate even more heat, further shortening tool life.

 

Fortunately, there are some broad steps manufacturers should consider in effectively approaching titanium machining, and find the sweet spot where best practice tooling and optimal efficiency come together with required tolerances:

 

  • Material selection: the manufacturing operation will vary depending on the titanium alloy to be used. The industry standard, titanium 6-4, is not necessarily the best material for the job. Consider different alloys of titanium depending on the final end use of the part, and only then consider the necessary machining parameters for the individual alloy.
  • Equipment: carefully consider the equipment you will be using to machine titanium. Does it need to be replaced or upgraded? It must be rigid to withstand and cut such a hard material, whilst capable of generating the geometry of the component.
  • Tooling: consideration should also be given to proper tooling, which must be able to deal with the high heat and additional wear that titanium generates during machining.
  • Machining parameters: everyone wants to cut and machine as efficiently as possible. However, the more aggressive the cut, the more heat is generated and the more wear is inflicted on the tool. What is already a key issue in machining titanium will be compounded.
  • Verification: an effective way to test the setup, without wasting titanium, is to first run aluminum through the machine, to ensure the part will be suitably tolerance and well within spec.

 

Titanium manufacturing depends heavily on operator experience. The more experience you have, the more quickly you will know what will work and what won’t.

 

Getting this experience up front, and considering where it will come from before you try to implement a titanium capability at your facility is critical to avoid unnecessary delays. Consulting a third party on how to machine a part will speed up implementation greatly, rather than going through trial and error, and a lengthy learning curve, yourself.

About the author

Dr. Radu Pavel

CTO