This is amazing! How did you get the pictures?

I spent a long time with various chemical processes to remove the layers of the chip before discovering that 1500-grit sandpaper works shockingly well. Then I took the pictures with my metallurgical microscope and stitched the images together with a program called Hugin. I wrote a blog post about the process: https://www.righto.com/2015/12/creating-high-resolution-inte...