Grinding Titanium 3

[rwild]

Has anyone had any experience with grinding Titanium. I need to remove material on some very thin 6al-4v. We have tried milling but we are tearing the corners. If you can grind it, is there a recommended wheel, grit , coolant,etc. Thanks all.

 

[CoryPad]

Grinding can be used for titanium alloys. Compared with steels, you need to use a more gentle process. From the ASM Handbook Volume 16 Machining:

Wheel Grinding

Selection of wheel, wheel speed, and fluid is important. For hard wheel grinding, vitrified bonded wheels are the most effective. Aluminum oxide (Al₂O₃) wheels give good results when limited to grinding speeds of 10 m/s (2000 sfm) or less. Silicon carbide (SiC) wheels can be used at 20 to 30 m/s (4000 to 6000 sfm) if higher speeds are desirable. A feed of about 0.025 mm/pass (0.001 in./pass) is generally suitable for all wheels. Abrasive grit size of 60 to 80 and wheel hardness medium grades J to L are commonly used.

The workpiece can be flooded with standard grinding oils. Water-soluble nitrite amine solutions (rust inhibitors) also work well with aluminum oxide wheels. Silicon carbide wheels, however, operate best with sulfochlorinated grinding oils. Complete flooding of the workpiece minimizes the possibility of fire. A 10% solution of nitride rust inhibitor in water eliminates the risk of fire but is less effective than oil with SiC wheels. Water-soluble oils are also useful but are less effective.

 

[unclesyd]

We make synthetic fiber spinnerets (8"x12"x1") from Titanium. We finish the blanks by grinding on a Blanchard Grinder to get a flat and parallel faces withing 0.0005". After drilling the counterbores and capillaries we then diamond lap both faces.
Our grinding normally removes a total of about 0.010" of metal from the blanks.

 

[saberblue]

The use of nitrides in any form in metal working fluids particularly in conjunction with amines raises a great many health and safety issues -- other than that I agree with what Cory had to say

here is a link to a TRIM Technical Bulletin on this subject that should provide additional background

http://www.masterchemical.com/db-docs/technical-bulletins/HSEA_Nitrites.pdf

A.R. "Andy" Nelson
Engineering Consultant
anelson@arnengineering.com