Galling on Alumin(i)um alloy

ChrisR · Post by **ChrisR** » Tue Feb 05, 2019 10:33 am

As a teaser, What's that? (solved so title changed)
The colour is misleading, I left it because it shows information.

grgh · Post by **grgh** » Tue Feb 05, 2019 5:05 pm

Part of a plank of wood?.

ChrisR · Post by **ChrisR** » Tue Feb 05, 2019 5:30 pm

4MB download:
https://ufile.io/3nlci

It's not wood colour - the colour balance is off.

bralex · Post by **bralex** » Tue Feb 05, 2019 6:59 pm

Razor blade?

ChrisR · Post by **ChrisR** » Wed Feb 06, 2019 3:07 am

No,.
Its actually part of a microscope....

Pau · Post by **Pau** » Wed Feb 06, 2019 3:13 am

Metal, I think, a damaged or defective machined part

leonardturner · Post by **leonardturner** » Wed Feb 06, 2019 5:29 am

A surface that has seen some friction and abrasion. Those are pretty deep "trenches" in the stereo images. Did you get sand in your focusing mechanism?

Leonard

ChrisR · Post by **ChrisR** » Wed Feb 06, 2019 2:24 pm

Yes, it's alumin(i)um alloy "galling". It's happened in an epi illuminator, where the cubes are slid across.
It had become tight, and came to me with one of the slider-arms missing, presumably broken at its weak point, where the second one had bent.
That's despite the grease costing $968 per kg.
A microscope repairer advised that a light lithium grease would do, but I may look for something anti-seize.

The grooves do look deep, don't they? But the entire stack (M20x) is only 60µm or so. It was tilted a little to give some shadow, and the depth of the grooves was just covered.
The trenches are in focus, and FOV is APS length/20 so about 1000µm.
They do look a lot more than 1/20th the field width deep, huh?

The funny colour is Auto balance, on flash

.

This is the male dovetail surface. The carriers are a brass/bronze alloy.