Exploding Wires

In our summer camp (more info here, natch) we have an awesome demonstration that heats an iron wire via a variac that demonstrates the solid state phase transition from BCC iron (at room temp) to FCC iron (at higher temperatures).

This video heats wires of various metals at - I think - constant voltages - and observes a few interesting things:

• copper wire produces a green flash at the moment of melting
• magnesium ribbon rose as it heated and expanded (rather than sagging) at first
• molybdenum wire produced a series of evenly spaced 'balls' (unduloids) before melting and breaking

I've seen something somewhat similar to the molybdenum balls when the iron wire melts and fails. Each end of the iron wire creates one single ball of iron on its end where the wire failed. We don't get the repeated drops like molybdenum, but the metal balls are familiar to me.

I appreciate the explanation of the formation of unduloids forming via partial melting and surface tension pulling the molten surface together. Sounds good enough to me.

I do wish they had repeated the 90 degree turned experiment with the molybdenum wire - not just with the copper wires.

Molten Steel Exploding at 10,000fps - The Slow Mo Guys

There's not a ton of science in today's video, just some ridiculously slowed down footage of molten iron being smacked with a cricket bat by two British guys - thankfully with good personal protective equipment (PPE) for themselves. 

...but at least it's really, really pretty footage.

Making and Casting (Principles of Metallurgy)

This is a very information dense video explaining...

• where iron ore comes from and what it contains
• how blast furnaces purify iron from ore
• forming the iron from the furnace into steel
• arc furnaces melting and purifying already formed steel
• further steel refining
• casting of the steel into shape via...
• sand casting
• continuous casting
• ingot casting

This would be a great summary of the steel processing processes in class.

There's not much exciting to watch. I'm keeping the tone of my writing this week in line with the tone of the video so you know what to expect.

Thank you for reading.

Launching molten iron with a shovel

There's no info posted with this video...none at all.

The original was posted to reddit (in a subreddit to which I'm not going to link because of the problematic title), and there wasn't any info there, either.

I do appreciate that the two gents (I'm assuming gents, though I could be wrong) are in full PPE...

...unlike the guys in this video.

Iron wire demo and where to buy the supplies

Update (12/1/24): You can order the wire online from Ace Hardware now - either in 50 ft lengths or in 1540 ft lengths.

For some ridiculous reason, one of the hardest supplies for material science teachers to procure is the iron wire for our iron wire demonstration. It should be the simplest thing in the world to get because it's one of the least complicated things to make, but - for some of us - it's amazingly hard to find just the right wire. Though the TruValue near Chillicothe, MO seems to stock it in bulk, my local TruValue doesn't understand what I want with it and doesn't have it on hand.

Here's (above) a picture of the iron wire (anchor wire, stovepipe wire, black wire) that is exactly what we use in the summer camps, and here's a video of the demo as we perform it, too. That's Master Teacher Caryn Jackson there on the right. She has a nice variac (and some 15-amp fuses) to use. Some of us envy her for her awesome variac.



...and the same as narrated by Beth Eddy...