Nitinol: The Shape Memory Effect and Superelasticity

The initial part of this video from The Engineering Guy isn't anything new to most of us teaching material science: NiTiNOL changes shape as its temperature is raised. From there, though, this video does a great job showing animations and graphics explaining what's happening within NiTiNOL when its temperature changes. 

I haven't heard the explanation of the mirrored or non-mirrored rhombic crystals. That's really interesting, and I'd admittedly like to get some confirmation from an expert that it's not an over simplification. 

Anodizing (Or the beauty of corrosion)

Hey, Bill.

This video - as promised earlier this week - gets into the explanation of how anodizing creates the beautiful colors via interference rather than by actual light absorption. 

It turns out that titanium and aluminum don't necessarily get tinted the same. Aluminum is often anodized and dyed.

Who knew?

Plastic Injection Molding

Well, if they're going to talk about - and briefly focus on - how Lego bricks are made (not Legos, ya savages), then I'm going to post the video.

Our material science class at Princeton High School doesn't get anywhere near practicing injection molding. One of our dreams out in the distance is to sometime get to lost wax casting, but that's about as close as we've considered. In this video, however, The Engineer Guy does a great job explaining the process of injection molding and a bit of the history of celluloid because one of the claimants for the invention of celluloid is the inventor of the injection molding process.

Plus there's the Lego connection...more of which after the break...

The ingeneous design of the aluminum beverage can

Holy crap is the aluminum can complicated.

Maybe I should stop throwing them into the back of m'pick up truck and just letting them blow away into the coutryside.

Seriously, though, the aluminum can is - as are so many of our modern technologies - an absolute marvel of engineering. The number of steps involved in turning a 0.3"-thick aluminum disk into the finished can is stunning. Also stunning, by the way, are the examples that The Engineering Guy has along every step of the process. I'm desperately curious - and more than a little envious - as to how he got his hands on all of those.

After the jump I'll include all the videos he references at the end of the above video.

Concrete: A slightly tongue-in-cheek look

That's a big piece of sewer pipe. It's kind of weird that it's in sharper focus than is the rest of the frame, though.

The Engineer Guy makes some concrete - apparently from quickcrete - and then waits for it to set while his sample cures.

At 1:45 he says that concrete doesn't really dry and explains what's really happening. Then, though, at 2:05 he says he's going to wait for the concrete to dry. Sheesh...

Copper: The Miracle Metal

The sound is all out of whack here, but if you hang around for the outtakes at the end of the concrete video, you can see why they had to use such extensive overdubbing.

I do dig the smooth slide to the right at 1:33.

Copper's five properties are - in case you missed them...

1. inert to water
2. easily shaped
3. plays friendly with other metals
4.    
5. 100% recyclable   

 ...or maybe they're...

1. easily shaped
2. conducts electricity
3. tolerates heat
4.   
5.   

I totally agree with The Engineer Guy in everything he said about copper. It's very cool.

But I might like things to be a little more linear when he's listing five things.

How a lead-acid battery works

Batteries are just so freakin' cool.

I had no idea the specific chemistry inside a lead-acid battery. Lead plus lead oxide making lead sulfate in each case...brilliant.

The comment at 3:00 - "with most engineered objects, there are going to be trade-offs, giving away the characteristics you want to gain others you must have" - is a marvelous summary of much of our design challenges.

Light bulb filament

This video, made to accompany an article on Wired magazine's website, absolutely blows me away. First off, the ease with which The Engineer Guy takes off the glass envelope of the light bulb at 0:45 is stunning. Can anybody recreate that with a pipe cutter? I've been trying for a couple of weeks with absolutely no luck.

At 0:58 then, the video does a great zoom in on the supercoiled tungsten filament and shows the original 20-inch filament coiled then coiled again.

The next part of the video - from 1:30 through 2:30 - explores the ductility of tungsten and the processes necessary to make it ductile. The six steps - at 2:00 - absolutely blow my mind. That anybody could ever figure those steps out is amazing.

And the video closes with explaining the need for the glass envelope and the gas within.

Great, great video!