Steel Metallurgy - Principles of Metallurgy

Again with the mAtallurgy Data channel...

Maybe they're trying to combine material and metallurgy into matallurgy?

Whatever portmanteau they're aiming for, their videos are excellent for understanding metals. This one goes over how different metallic ingredients affect the properties of alloy steels, the carbon-iron phase diagram, CTT and TTT graphs (something I haven't seen before, admittedly), hardenability, and ways to strengthen steel.

It's not necessarily written for my students' levels - most of them, anyway - but it's good background understanding for me to have.

Properties and Grain Structure

Properties and Grain Structure: BBC 1973 Engineering Craft Studies

Yup, 1973...that means not only is the narration done with an English accent, it's also paced for a 1973 world meaning I ran the video at 1.5 speed to bring it up to a modern pacing.

The video shows the etching process for various metals then does it again after cold rolling the aluminum sample, then discussing how the material's properties (ductility, hardness, toughness) change.

The video then repeats things for heat treating after cold working the aluminium (sp?)...then various carbon steels being annealed, quenched, and tempered.

I absolutely love the hand-cranked tensile tester that we see at around 8:10 in the video.

It's a great video for showing the properties and crystal structures of aluminum (sp?) and steel and how the crystal structures coordinate to that.

Understanding Material Strength, Ductility, and Toughness

Strength vs toughness is such a subtle concept for my students to understand.

That isn't really a tough (sorry) thing to reason out. The two words are used somewhat interchangeably in the non-material science world. 

This video does a great job animating and showing the differences between those words and using the stress strain curve to do so. 

Understanding Metals

Well, that just about covers the entirety of our metals chapter for both our summer camp and our year-long material science course.

If my students could understand the totality of this seventeen-minute video, they would rock my end of chapter test. It covers...

• BCC/FCC/HCP
• crystalline v amorphous
• slip planes
• defects - point, line, and screw
• grains and grain boundaries
• cold working / work hardening
• alloying - both substitutional and interstitial
• heat treating
• two-phase alloys & precipitation hardening
• the iron/carbon eutectic diagram with ferrite and austenite

Thankfully the video is incredibly well laid out, animated, and presented. This would make a great end of the chapter review for students to watch.

Can you GROW an Opal?

Opals are pretty.

Full stop

And they are incredibly rare and labor intensive to mine.

So why not just make them at home?

All it takes is seven or so months, a fume hood, some ethyl alcohol (purer is better), tetraethyl orthosilicate, ammonium hydroxide, a stirrer, water bath, hot plate, resin, a vacuum chamber, and apparently infinite patience.

I looked into buying them, and even the synthetic ones aren't terribly cheap.

Wind energy has a massive waste problem. New technologies may be a step closer to solving it...and...How can companies recycle wind turbine blades?

 

From the CNN article

Wind energy might be the solution - or at least part of the solution - to our energy problems. We absolutely need to stop burning things (methane, oil, coal, wood, trash, retired Beanie Babies) to make energy. That is not in dispute.

One of the things that is in dispute, however, is how to deal with the waste from retired wind turbine blades. From the same article, "[b]lade waste is projected to reach 2.2 million tons in the US by 2050. Globally, the figure could be around 43 million tons by 2050." The blades are, as a CNN article writes, "made from fiberglass bound together with epoxy resin, a material so strong it is incredibly difficult and expensive to break down." 

Recycling the themoset resin is challenging, though a company named Vesta "has been working on in partnership with Aarhus University, the Danish Technological Institute and US-based epoxy company Olin, uses a liquid chemical solution to break down the blade into epoxy fragments and fibers. The epoxy resin is then sent to Olin which can process it into 'virgin-grade' epoxy"

There are other possible solutions mentioned in the article - pyrolitic separation of the resin and fibers allowing both to be reused, chopping the composite blades into fragments to then mix into cement, and...well...not much else.

A C&EN article explores the same issue and adds in an option of repurposing the blades rather than recycling them, showing an image of a playground made of decommissioned blades in the Netherlands and saying that they have also been turned into bus shelters and other public structures. The article also reports that there are companies exploring making the blades out of more easily recycled materials, though little detail of what those materials could be are provided as the materials and processes are still being devloped.

Making a BULLETPROOF John Wick Suit in Real Life!

I love the John Wick series. It's ridiculous and phenomenally unreal that the main character would survive even the remotest bit of the damage done to him throughout the series of films.

With that being said, I guess a bulletproof dress suit similar to John Wick's is possible. I say that because this video is about the process of making just such a suit.

There is a lot of firing of guns - all on a controlled, safety-checked gun range, at least - in the video. The high quality stuff to me is the initial exploration of how they should do the testing to see which materials are bulletproof and the minimum of those materials that they can use. The try to cheap out on the testing methods initially but come to realize that the testing standards are written because the standards describe the ways that actually work. I appreciate that.

I also appreciate the discussion of composite materials even though the sheer-thickening fluids from my previous post didn't seem to provide any advantages, which is a little disappointing.