aluminum surface pitting
aluminum surface pitting
(OP)
We have found some surface pitting on a CNC turned aluminum part (7075-T6) due to the machining process. It was previously run on a high speed Hurco machine (without the problem) but recently changed to a older and slower CNC. Anyone experienced this before and have an idea or two to where to begin?





RE: aluminum surface pitting
If the pitting was found during machining it is probably a bad batch of material.
RE: aluminum surface pitting
I will check on the preservation technique we are using and see if that could be a problem. Another thing of note - it that after cleaning these parts they are not subjected to any finishing process that would leave a protective coating (none specified on the print anyway). Older vesions were anodized but prior to my arrival that finishing process was halted for cost reasons. This may be my ammunition to bring it back if it ends up being a corrosion problem.
RE: aluminum surface pitting
RE: aluminum surface pitting
thanks
RE: aluminum surface pitting
These may seem elementary but are the two machines running identical tooling at identical parameters? Do new parts from each machine show any differences?
Griffy
RE: aluminum surface pitting
RE: aluminum surface pitting
RE: aluminum surface pitting
My experience with aluminum (admittedly limited to a few cast and wrought alloys) was that some combinations of operating parameters had a tendency to "wipe" material across the surface. When a little oxidation occurred these areas often lifted and left a spot or area with a different appearance.
Could this be what you are experiencing?
Griffy
RE: aluminum surface pitting
Chris
Sr. Mechanical Designer, CAD
SolidWorks 05 SP2.0 / PDMWorks 05
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