Ti-6Al-4V Heat Treatment

[sushi75]

Hello!

I'm currently working on a structure made of Titanium, Ti-6Al-4V, and it is heat treated to improve mechanical properties. So I''ve been through a lot of books, documents, internet to get a better understanding of the heat treatments, and now I'm a bit confused. So I need some help to get my mind clear about that!!

In this case, the alloy is Solution Treated and Aged. So what I understand is that (please correct me if I'm wrong!!):

1-first the part is heated up above the beta transus temperature.During this step, the recrystallization occurs and new grains form, in the alpha phase.
2-then it is quenched. so the microstructure remains in the alpha phase.
3-at this stage the material is stronger but brittle so the idea is to soften it. this is done by doing tempering. increase of the temperature below the beta transus, and the idea is to make it softer to increase ductility.

In the case study there are parts STA ans other Milled Annealed. Is annealing process just consists of heating up the materials until it becomes ductile enough?

Many thanks for your help, the more information I try to get the more confusing it becomes!

Cheers

 

[EdStainless]

Try this:

http://www.dtic.mil/dtic/tr/fulltext/u2/675464.pdf

The alloy is a+b, and the ability to achieve the solution anneal+age hinges on sections being thin enough to quench.
Many structures are annealed+stress relieved because of thickness limitations.

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P.E. Metallurgy, Plymouth Tube