[Erik Mannie]

I have never worked with Ti, but I need to make a bunch of parts with .071"-.078" titanium sheet. I will try to work with Grade 5 6AL-4V first, but if I can't bend and weld it then I suppose I could use Grade 2 CP-2.

I bought some on eBay which is coming from China, but I think that I will be using a domestic supplier for future orders. I am not finding the Alibaba ordering system very user friendly. The first supplier that I contacted wanted to do the deal outside of Alibaba; this seemed like a red flag (pun intended).

With the sheet, I cut two pieces: 5" X 4" and 5" X 1". I then bend it by hammering it on a 4 1/2" OD mild steel pipe. Then I grind the pieces so that they fit up together for a single weld bead.

My questions are:
(1) Will this be hard to cut? The 6AL-4V is annealed.
(2) Will I be able to pound on it with a sledgehammer to bend it, or will I have to heat it and then pound on it? I will cover the steel pipe so that it doesn't contaminate the Ti.
(3) Is it overly challenging for a noob to weld 6AL-4V? I bought the proper filler rods: ERTi-5 for the Grade 5 and ERTi-2 for the Grade 2. I have never welded on Ti before, but I need to learn how.
(4) Are my instincts correct to buy the sheet from a domestic supplier? I think I will have enough trouble cutting, bending, grinding, cleaning and welding the Ti. I just don't want to introduce delays or QC problems.

I am confident that I would be able to weld on the Grade 2, but I really want the Grade 5 for my application. Strong and light!

I may also be encountering an issue with galvanic corrosion. I want to use Grade 12.9 steel bolts. The shank of the bolt will be in a hole in the Ti. I could use plastic washers against the Ti so that I could use a steel nut. I really don't want to spring for Ti bolts.

What I have read about galvanic corrosion leads me to believe that the steel bolt (shank) will suffer the consequences of the dissimilar metals. The Ti part that I am making will spend its life inside a bicycle tire, so no high temperatures and very little moisture. The tire gets bald after about 6-12 months, and all of the bolts come out at that point so I would be in a position to inspect the bolts for corrosion and replace if necessary. I may use latex tire sealant in there, but I imagine that I am on my own with that slimy mess.

[LtBadd]

I'm not sure how difficult it will be to cold work it, but it will be challenging . Welding Ti isn't hard as long as you have the proper gas coverage, if you can't back purge then use chill blocks

[Erik Mannie]

I'm not sure how difficult it will be to cold work it, but it will be challenging . Welding Ti isn't hard as long as you have the proper gas coverage, if you can't back purge then use chill blocks

It says here https://titaniumprocessingcenter.com/gu ... e/grade-5/ that the bend radius https://en.wikipedia.org/wiki/Bend_radius is 5.0 X thickness, so my bend radius of 2 1/4" is well within this limit.

There is some contradicting advice here https://www.practicalmachinist.com/vb/g ... eet-89565/ on bending Ti sheet. I will try cold working as well as heating to an orange color. It sounds like it can be done. I was concerned that the Grade 5 is so brittle that it would break upon cold working, but I shall find out soon and post here how it went.

I think that the welding the annealed 6AL-4V will be the least of my problems. It says here https://www.twi-global.com/technical-kn ... alloys-024 that the Grade 5 is "readily welded in the annealed condition".

I don't have any idea how I will cut the Grade 5. All I have is a cut-off wheel, cut-off saw https://www.walmart.com/ip/Grizzly-G074 ... /142269764 and hacksaw at home. At work, we have a metal bandsaw almost exactly like this http://www.boltontools.net/BS-1018B. I am confident that this could cut .078" Grade 5 sheet!

[Erik Mannie]

I got 25 5" X 5" squares of .071" 6AL-4V sheet for $5 each from Sackin' Metals in Huntington Beach, CA. That wasn't too bad of a price. The quotes that came in from Alibaba were higher than that, and I will be happy to work with domestic material.