Revealing Secrets of Homemade Metal/ Bronze under Microscope

I made bronze crysknife from Dune in my previous video and I was curious what is inside the bronze I prepared for casting the knife. I did expect some fllaws like some sulphur residues (sulphur sulphides), since i used copper sulfate (chalcantite) ore as the source of copper.
#casting #bronze #microscopy

[@lilanedaria]

Nice work! I quite enjoy your videos. I hope the algorithm gives you more visibility. Keep it up!

[@JustAnotherCraftsman]

Thank you, appreciate 🙂. My channel is long time driven by my curiosity and by being unable to stay still. It would be nice, but I don't expect it. But I'll definitely work on constant improvment 🙂.

[@hardwareful]

Amazing amount of sample prep for such a video. I wonder how the crack formation came about - does the volume of the beta phase regions change so much?

[@JustAnotherCraftsman]

Thank you! I'm new to bronze structures, so I might be wrong, but my guess is relation to beta, gama, delta crystal structure change. I'm not sure about beta, but delta is relatively fragile so volumetric change plus fragility might be the cause. Another reason might that it is broken into a pore behind it.

[@dav1dsm1th]

Interesting. Does the outer edge of the crossection exhibit a different structure - as it may have cooled more quickly? Or would the heat from the interior have to pass through that region, making the structure fairly homogenous? Thanks for the videos.

[@JustAnotherCraftsman]

Hello David, Thank you for your feedback! I would say that apart from the peripheral porosity, probably caused by the violent burning of the petrobond sand, it is fairly homogeneous. There is no systematic distribution of individual phases. Here and there there are random areas enriched with delta phase, so there are literally islands of alpha surrounded by light blue colored delta, but other than that, and some random cracks, it's similar. There is one interesting phenomenon that I forgot to mention, the streaked lines that look like smudges revealing the different orientation of the dendrites. I'm planning a follow-up video showing the changes caused by annealing and peening... somehow I'm hooked by the topic :), because it kind of intersects with my daily job.