Surface Finish Requirements (Ra 150) for Blasted Titanium Surfaces

[Ti QE]

My customer is responsible for the bonding operation; the surface roughness requirement helps the adhesion process.

[Ti QE]

In Reply to Parent Post by Crash Not

If it is an issue of "ours versus theirs" than maybe both profilometers should be calibrated to the same master. Or create a sample part and have them check it and indicate where the check(s) were made, in which direction, number of checks, ect., and keep that part for your reference.

We've exchanged sample parts with defined areas marked for measurement, defined measurement procedures and methodologies (direction, profilometer settings, etc) and eliminated variables from the process.

[swapnilmarne]

Hello Ti QE ,

Can you give detailed specification for roughness, roughness tester used make, maximum sampling length to be covered ?

I can give some inputs after receiving the data.

Regards

Swapnil

[Phil Fields]

Hello Ti QE,
Is adhesion the reason for the roughness? If yes, have you worked with your customer to determine the roughness (that you can produce) to give the best possible adhesion results?
It seems like you are worried more about the measurement comparison between you and the customer, when the solution is more centered on the adhesion process.

Phil

[Ti QE]

All - I've been in contact with Mahr Federal and Mitutoyo (both profilometers were used to check surface finish and both had problems) and they have advised that their instruments are not the best method to measure surface finish on a grit blasted surface. Both instruments have issues with the surface irregularities (stylus gets caught on rough edges, stylus bounces, etc) which results in the diamond tip being ripped from the mountings thus causing the instrument to throw errors. Normal time between stylus replacement runs from one week to ? depending on usage. I've decided to use optical laser scanning (yes, it's expensive) to determine Ra values but it seems to be a definitive answer to the problem at hand.

Thanks to all for your comments and suggestions.