TI- Heat treat?

The times and temperatures sound about right, but I know nothing about the cleanliness issue. If someone doesn't have an answer for you, ask again, and I'll look it up. I have the ASM book that covers the subject.

-- Ed Huntress

messagenews:XNednQcnaLktDmbanZ2dnUVZ snipped-for-privacy@giganews.com...

I don't know about the times and temperatures, but I know that work on Ti alloys at elevated temperatures demand scrupulous cleanliness. Most heat treating and welding of Ti alloys is done in inert atmospheres. They sell a stainless steel heat treating wrap that is used to prevent oxidation in the heat treating furnace. This might be a good product to try. I see it listed in nearly every major tool catalog.

Thanks for the replys!

I have some of those SS bags for heat-treating but didn't have much luck last time tried to use them, was concerned about the part cooling while I opened the bag to get it to quench (at 1650F!).

Anyone got any tips? Do you put a match in with the part to "burn" the air inside?

Anyone?

I think you just quench everything. When I have seen it used, a tool that looks like a window-screen spline tool and a J-roller have been used to smooth the SS around the part, basically eliminating all the air. The goal is to effectively "plate" the part in stainless so that there is no Ti exposed to the furnace. You definitely would not want to put a match inside because the carbon from the flame would be bad.

Someone wanted a follow up to this so here you go...

I tried a small bit at the temps. given and it did harden it quite a bit, it could still be filed (barely) but was noticeably stiffer. Problem is that it warped the thin (0.030") sheet slightly, which isn't good for the application.

Any idea how I can keep thin sheet flat during the process?

ps: Didn't use the SS bags, there was a layer of white oxide before the quench and the finished part came out dull, but that's OK.

When you say "stiffer," do you mean it acts like a stiffer spring, or that it has more resistance to permanent bending? Titanium has some strange properties but you shouldn't notice any difference in springiness (there is some, but it's too small to detect without careful measurement). However, it will show more resistance to taking a permanent bend.

That's always a problem when you quench thin sections of metal. There are some methods. You might want to check with people who make custom knives. They ought to know.

-- Ed Huntress

It resists bending a whole lot better, which is what I needed. Never thought of the knife folks, would they use 6Al4V?