Request for material recommendation for a Titanium grade or similar lightweight material with high yield strength

Hi everyone,

I need to machine two small parts. One part requires a yield strength of 100,000 PSI and one part requires a yield strength of 200,000 PSI. It's probably best to machine the parts from stock that has a thickness near the part thickness. There are some small internal radii and a small cutter of 1/4" OD will probably be needed for much of the machining and a 3/6" OD cutter for a few other small inside radii. I need a lightweight material preferably similar in weight to Aluminum. I'm guessing that Titanium is the best compromise (perhaps the only one) even though it's a little heavier than aluminum it's still lighter than steel.

I've listed the overall dimensions of the two parts below along with the required yield strengths.

Part #1 overall dimensions (required yield is 100,000 PSI)

Part # 2, overall dimensions (required yield is 200,000 PSI)

Part 2.339=94 thick

Here is what I found in Machineries Handbook...

5 Al, 2.5 Sn (low O2) Yield =3D 108 KSI condition is annealed

I have no real experience with Titanium, they list Alpha, Alpha-Beta, Near-Alpha, & beta alloys but I'm not sure what the real differences are.

For a few parts this small, what is the general difference in cost (materials plus labor) as compared to making the part from aluminum or steel ? Aluminum and non-hardened steel are probably out of the question at both the required yields, but I'm just curious how titanium would compare.

How hard is Titanium to machine ? How does it compare to Aluminum and say 4140 pre-hard ? I'm guessing it must fall somewhere between these two ranges.

I would appreciate any recommendations for a specific grade of material and any tips for machining.

Thanks John