Sunday, August 31, 2014

Aluminum Thermal Explosion

And that, my friends, is why you always need to keep your mold totally, absolutely, perfectly dry when you're pouring molten metal. Steam explosions suck.

This is not something to laugh about...unless you're Russian, I guess.

Looking into an electric arc furnace with the power on

How the heck? Why are they that close?

And if the camera is shaking like that, is it being held by hand?

Back up, dude.

Admittedly, though, seeing the molten iron bubble and spit and boil like that is stunning to see, and I am thrilled that some nutcase - make that sentinel76 - stood close enough to let me see that.

Here's what I would assume the process would look like from much further away. Skip to about 1:38 to see the electrode fire up and the above process begin.

Charging the furnace

I was lucky enough to get to tour the Nucor steel plant in Tuscaloosa, AL a couple of years back for one of our summer ASM Teachers Camps. At that plant they use an electric arc furnace to melt their scrap iron which they then mix to the desired composition of steel. I remember seeing them charge the furnace with recycled scrap iron and thinking it was just about the scariest, brightest, most awesome thing I had ever seen.

I don't know where Christopher Birkbeck - the poster of the above video - was touring when he filmed this video, but I imagine it's a pretty similar set-up to what I saw in Tuscaloosa.

My understanding of what's happening is that the scrap iron has some organic compounds on it - oil, paint, um...paint and oil - which immediately vaporizes and burns off on contact with the already molten iron still in the furnace. This is further fed by the release of oxygen from any rust that is on the scrap iron.

The flare really is outstanding to watch.

Honestly, the best tours we take in the summer are almost always the dirtiest tours.

Thankfully, the two charges we got to see on our tour didn't look anything like this one...

Ours looked a lot more like this...

Really, I could watch these videos all day long...

Tensile test

Computer modeling is so cool.

Like in this tensile test, you can see that the force concentrates as the cross sectional area of the sample decreases, leading to more and more drastic necking.

I can't see that when I look at a real sample being tested, but with the rainbow coloration for the different amounts of force, I can kind of show that to my students.

Water Balz Jumbo Polymer Balls

Such cute, bouncy little music from a video about fun, deadly little toys.

Ok, deadly might be an overstatement, but the jumbo growing spheres available from various companies have been recalled because, as written on the US Consumer Product Safety Commission's website...
The soft and colorful product can be easily mistaken by a child for candy. When the marble-sized toy is ingested, it can expand inside a child’s body and cause intestinal obstructions, resulting in severe discomfort, vomiting, dehydration and could be life threatening. The toys do not show up on an x-ray and require surgery to be removed from the body.
That's a bit of a bummer as the gel spheres are great in class for demonstrating index of refraction, lensing in an eyeball, crosslinked polymers, and osmosis & diffusion and as a medium for watching seed germination. Some companies - including Education Innovations, a favorite of the ASM teachers camp program - are still selling the spheres in smaller sizes, but it appears that the giant spheres are no longer available because they can sort of stop of the intestines.

Which is bad...

...but isn't as bad as ingesting Aqua Dots would be.

Yeah, the egg survived and all, but I'm not sure I'm going to be able to crack it one handed and scramble up an omelet with it afterwards.

Though it could make dying Easter eggs a lot quicker. Line those suckers up and spray like fifty of them at once.

Plus you could probably reuse the same eggs every year for like a decade.

Line-X was mentioned by one of my students in class this week, and he asked if I could explain how it worked. I'd never heard of the stuff, but I went home and watched the video...videos, honestly, as the company has posted nearly eighty videos of their product in a huge range of varied uses. The next day we watched the video in class, and I gave my very brief explanation of what I understood about the coating. It's a polymer that provides a lot more wear resistance and durability for the watermelon, egg, plastic cups, and cement block shown in the video.

It's actually fascinating to see the uses - military protection, flooring applications, truck beds (the primary application from what I can tell), wall coatings, storage tanks, protection of underground reservoirs, and lots more - that can come from slight modifications of the basic product.

Wednesday, August 13, 2014

Corrosion found inside the 520 Bridge pontoons

"Local news station finds corrosion in" random piece of infrastructure isn't exactly the hardest news story to go about finding. It involves checking any bridge, overpass, train tunnel, subway car, or...well...anything made of metal at all, pretty much.

It's just the natural order of things. Metals are just ceramic wannabes.

This article is interesting in that it's a floating bridge in Seattle, WA, and its supports...

from Wikimedia
...that get churning water and weather like this...

from wsdot - check out the waves just on the South side of the bridge

microstructure grain growth simulation

In high school I won tickets to an Allman Brothers Band concert from a local radio station. At the concert they had an old-school, bubbles-of-oil-and-colored-water on an overhead projector light show.

For some reason this video reminds me of that light show every time I see it. Yeah, it's a simulation of crystal growth showing 'grains' growing together, but I can imagine that it would be a bit more fascinating with some music and recreational drug use (not that we - ASM, Master Teachers, the DAR, the LDS, or Jeff Bridges - would ever endorse that.

We do, however, fully endorse using this video in our summer teacher workshop powerpoints.

Google Science Fair: Meet Elif Bilgin

I had a student last year figure out how to make a bow and arrow out of a paper clip and a rubber band from his braces.

That's practically as awesome as make a bioplastic from banana peals, right?

Sunday, August 10, 2014

World Cup Chemistry: The Science Behind the Brazuca Ball - Reactions

The American Chemical Society worked with Compound Interest to produce this video on the chemistry of the polymers involved in producing the World Cup soccer futbol ball, the brazuca.

Oh, and am I too late to root for Australia in this year's World Cup?

What happened to this car?

I can answer that question: something bad happened to that car.

See? Genius.

Check out this nicely animated video explaining the process of liquifaction which turns quicksand into a liquid, allowing things like cars, people, small pirate villages to sink into them.

It's sort of the opposite of what oobleck does.

Misconceptions about heat

In today's video Dr Derek Muller of Veritasium takes a few minutes to again tell people that they're wrong. He seems to do that a lot. I'm not saying, but I'm just saying...

The informality of the testing that he does is one of Muller's great advantages since it leaves the viewer fairly well able to reproduce many of the experiments that he does. Yeah, he uses an infrared thermometer here, but that's not radically out of the realm of expenses for most folks.

The testing today is looking at whether a book - apparently an Asimov tome - is warmer or cooler than an aluminum-cased hard drive. The trick is that they're both at room temperature...the same temperature. It's just that the two materials transfer heat very differently.

There's a similar video with slightly higher production value also by Dr Muller over on the Catalyst, an ABC Australia program, website. The video there is downloadable but not embeddable, and it does have a nice transcript of the prettier video. They also have a larger version of the downloadable video, but it's not viewable in the US. It does, however, come with some teacher material.

Aluminum or gold? Which is more valuable? It depends.

The Smithsonian's National Museum of Natural History has an interactive, multimedia site called Dynamic Earth that explores some of the science involved in four areas: minerals and gems, plate tectonics and volcanoes, the solar system, and rocks and mining. The most interesting content for the material science subject is a mock assignment that a girl is given to explore which is more valuable, aluminum or gold. The link heads to a summary of the website contents around the topic and to a transcript of the video.

To get to the video involved today via the multimedia site, skip the intro, click to rocks and mining then mining, then minerals matter, and finally on Aluminum or Gold. Embedded there is a tiny (in size, not in length or content) video. I tried to find the same video over on YouTube or via Google but with no success.

I am linking to the non-multimedia version, because the multimedia version has only a single external link.

The world's largest gold coin

That's a heck of an expensive advertisement...go Canada!

Of course, we all know that "the Royal Canadian Mint sees a challenge and meets the challenge...the Royal Canadian Mint sees the standard and surpasses the standard...the Royal Canadian Mint raises the bar on excellence and is the artistic mastermind behind the world's most magnificant gold bullion coins."

I'm just trying to get a handle on the size of the coin, though. A hundred kilos is like, what, eight pounds in imperial units?

How It's Made Aluminum

And so goes the glory of Napoleon's really fancy knives and forks...

This video, from the How It's Made series, shows the process necessary to purify bauxite ore into useful, 'finished' aluminum.

Sadly, though, it is bereft of the corny joke that usually comes at the beginning of the How It's Made videos. I kind of miss the joke. Does that mean I've got Stockholm syndrome at this point?

ALCOA - Production Video

Aluminum is a miracle. Its reactivity is so high that our ability to purify it from its ore just stuns me, seriously stuns me every time that I think about it.

I warn you that this video is narrated by a British voice, so it does refer to aluminum as aluminium. Just thought you should know...

The video follows aluminum through the processing to take the ore into a somewhat finished form...
  • refining of bauxite ore (grinding, mixing with caustic soda - NaOH, and heating) into alumina
  • smelting the alumina in a bath of molten cryolite
  • passing electrical current through the mixture
  • processing of the ingots (at an ALCOA factory, of course) into plates
    • casting
    • homogenizing
    • scalping (sawing & milling)
    • heating & rolling 
    • shearing & cropping
    • horizontal solution treating (5:15 - which seems to use water, not a solution)
    • stretching 
    • precipitating/aging
    • conductivity testing & ultrasonic inspection (both non-destructive testing methods)

Tapping a furnace

I have no idea what direct, curricular material science connection this would have, but it's worth sharing.

I have so many questions that aren't answered by the video's concise description: "A tapper opening a taphole in the side of an iron furnace. Using an oxygen lance."
  • Why wasn't there already a hole?
  • How much did that dude have to get paid to do this?
  • Is this a regular occurrence, or did something go wrong to require this action?
  • What sort of safety equipment would have to be involved - because it doesn't look like nearly enough?
  • Is this a field trip we can take from one of the summer teachers camps?
  • Are either of those 'sentences' in the description really sentences at all? (Don't worry, I already know they aren't.)

Sep 11 - "Why the Towers Fell" - Nova PBS

It is human nature to look back with one eye to the future. If we can just figure out why that happened, we can make sure it doesn't happen again. That is, at its core, what failure analysis is all about.

NOVA, the PBS series, produced the documentary "Why the Towers Fell" looking at the conclusions of the engineers and scientists on the government's exploration panel attempting to answer the titular question. In their findings there are a number of material science connections...
  • tradoffs among cost, weight, and strength - particularly at 11:30
  • design constraints - 12:45 (designed for impact of a Boeing 707, the largest at the time of design)
  • mechanical testing methods (sheer, tension, vertical load) - 33:30
  • heat softening of the steel - 37:45, 44:35 (and throughout in small mentions typically as "the heat would have softened the steel")
  • failure analysis - all throughout, particularly at 45:00
NOVA also posted a website of information related to this episode, much of which is still online. Some links are starting to fail, however. The best of these are a very readable summary of the findings, the engineering history of the Towers, and a java interactive showing what metal atoms do as heat is applied.

This one's tough for me to post and was even tough for me to watch. I didn't have a direct connection to the tragedy of the Twin Towers, but I had at least one student who did, who knew someone on one of the planes. If it isn't already obvious, be aware that some of our students - or coworkers - may have closer connections and may still struggle with memories of the incident, of loved ones who were closer to the Towers, or even - like me - have memories of being in the Towers and being two or three relationship steps away from the tragedy.

Friday, August 8, 2014

Administrators go to camp at WSU for STEM refresher course


The summer camps are about a lot more than administrators. Administrators are, of course, welcome and have attended in the past. We'll just have to change a few of our jokes.

This article from the Ogden Standard-Examineris titled as though the camp attendees are all administrators, but the article itself doesn't mention a single administrator. The article describes a lab in the teachers camp - heat treating of steel; gets a few quotes from the two master teachers and a couple of attendees; and offers up a few reasons why the camp is important.

From Adam Johnston, Weber State University physics professor:
The purpose of this camp and science education in general is to promote enthusiasm for the sciences,” he said. “We would like to see a lot of different people working in the sciences. There are a lot of great employment opportunities, and STEM knowledge is great for future jobs and for the economy. And we believe that scientifically literate people are able to make better decisions for themselves, for their communities and for voting. Understanding science helps people understand the issues at hand and make better decisions.”

Thursday, August 7, 2014

Butte, America (part 2 - Montana Resources)

When last we left our intrepid explorers, they had seen the eventual outcome of the strip mining of copper, a toxic-water-filled pit.

Today our scene opens on the pit to the east of Berkeley Pit in the creatively named East Pit (or the Continental Pit according to Wikipedia) where copper and molybdenum ore is still being mined, ground, and purified by Montana Resources who were nice enough to host our teacher camp participants for a field trip. Big, big, big thanks to Tad Dale and the folks at Montana Resources. They were great hosts.

Check out their video of the processes at the pit.

Montana Resources module SD from Washington Corporations on Vimeo.

We started toward the end of the process, in the grinding and flotation plant.

Mike McGivern, in yellow, was our tour guide. Here we started our tour outside the flotation plant. Big thanks to Courtney Young (in white), our Montana Tech host.
Be warned, lots of photos after the jump...

Wednesday, August 6, 2014

Railcar filled with styrene begins to polymerize in Cincinnati - 8/28/05

The end of August of 2005 saw news in Cincinnati covering a story of a railcar spontaneously polymerizing styrene. The railcar was venting styrene and getting hotter thanks to the exothermic polymerization process.

You can catch a glimpse of the railcar being doused with water from 0:30-0:38 in this video...

The report from isitech's website says this...
The escape of gaseous styrene was observed from a safety valve on a stationary railway tank vehicle on the 28th August 2005 at approx. 5 pm, near Cincinnati at the regional airport Lunken in the state of Ohio. According to media reports, the tank vehicle contained approx. 24'000 gallons, that is about 90'000 liters of styrene. The tank vehicle belongs to a company that has been admitted to official quotation on the stock exchange with an ISO 9000 certification and a safety award "OSHA star site".


Because the opening of a safety valve requires an increase in internal pressure, one can assume that an exothermic (heat generating) reaction had taken place inside the tank. In the case of styrene, a well known reaction is the polymerization of styrene to polystyrene.
A stabiliser like 4-tertiary-butyl-catechol (TBC), which prevents polymerization, is usually added to styrene for transport and storage. In order for TBC to be effective, it is necessary that a certain concentration of oxygen is dissolved in the styrene solution besides TBC. Should no stabiliser be present or it has been used up, styrene can polymerize with oxygen to form a styrene-oxygen copolymer, benzaldehyde or formaldehyde.

Between 10-15 ppm TBC is added to styrene. Under ideal conditions, 10-15 ppm TBC stabilises styrene for approximately 3 months. The TBC can be used up faster according to oxygen concentration, temperature, humidity, rust or other impurities in the tank. In addition, a minimal oxygen concentration of 10 ppm. and preferentially of 15-20 ppm. is necessary.

The higher the temperature is, the faster the TBC concentration falls.


According to media reports, the tank wagon had been stationary at the site of the accident for 9 months. Due to this lengthy stationary period, the polymerisation would be likely to account for the rise in pressure.
Aristatek's website uses the incident as an example of a training document...
What caused the rail car to vent styrene monomer? The venting occurred because of an increase in pressure inside the tank. The website listed above explained that the increase in pressure was due to heat generated within the tank due to polymerization of the styrene monomer within the tank. Normally, a chemical inhibitor such as 15 parts per million of 4-tertiary-butyl-catechol (TBC) is added to the tank during transport to prevent polymerization. This inhibitor scavenges rust and other impurities within the tank that can act to initiate polymerization. Oxygen (about 10 ppm) is also required to be dissolved in the styrene monomer for the TBC to do its job. The TBC concentration decreases with time as it scavenges impurities; 15 ppm concentration would probably be mostly used up in possibly 3 months (even less time if ambient temperatures are warmer). The website mentioned that the rail car had been sitting there for 9 months. Without the inhibitor, the styrene monomer can polymerize with oxygen to form a styrene-oxygen copolymer or benzaldehyde and/or formaldehyde and polymerize with the release of heat. The heat further accelerates the polymerization releasing more heat. Fortunately, no explosion occurred, the chemical was not released all at once, and people were evacuated to safe distances. The safety valve did t he job it was designed to do, to release excessive pressure buildup slowly avoiding a catastrophic explosion. The error was that the rail car was allowed to sit there for nine months, during which time the inhibitor became depleted.
The Cincinnati Enquirer's website provides a day-by-day recounting of the entire event...

Westlake Chemical Company, the responsible party, did remove the railcar once the polymerization was complete and set up a claims process for local residents. One nearby resident died a few weeks later, and his death was attributed to inhalation of the styrene gas. Settlements ended up topping over $2 million (plus $400,000 for the city of Cincinnati, itself.)

This might've been bigger national news if it weren't for a little storm that hit New Orleans at about the same time...

Monday, August 4, 2014

These people love to collect radioactive glass. Are they nuts?

Far be it from me to claim that someone is nuts because of what they collect.

I have full three display cases of Lego minifigures hanging on my wall. If you happen to want to hang out with radioactive glass in your display cases, who am I to judge?

I've hard of vaseline glass and knew it was also known as uranium glass because of the uranium oxide in the glass. I hadn't heard of it being called canary glass, though, and I was never quite sure of the radiation dosage that any collectors would be receiving.

Luckily, this article, from Collectors Weekly clears that right up.


I love seeing the crystal grains develop as the acid etches the metal surface. It's just gorgeous.

The eight-and-a-half-minute video above shows the preparation of a few different samples, some of which show crystals large enough to be seen by the human eye as well as a few samples that have been etched through natural processes over time.

MaterialsScience2000 has ten total videos posted, and many of them are worth a watch, including a thorough explanation of the tests being preformed. Check out these, too...

A36 Steel Tensile Test

At about eight seconds in, I can start to see the necking which causes the force to concentrate on that area which causes further necking which causes force concentration...back and forth until catastrophic failure nearly at the end of the video.

Not much else to say here but that it's a nice video of a tensile test being performed. I just wish we could get a concurrent graph of the stress/strain curve being generated.

Here's another tensile test from a bit further away...

Playing with Polymers: make slime at home

Maki Naro is a webcomic artist with a blog on Popular Science's website. On the blog recently, Maki posted these instructions and explanations for making 'slime' from Elmer's glue, borax, water, and food coloring. (They're available in higher resolution over there.)

The instructions aren't anything revolutionary, nor is the explanation, but I look at this like Greg Louganis who always included an incredibly simple dive in his competition routine. Yes, the degree of difficulty was low, but he executed it perfectly.

Nice job, Maki.

Where are the ASM camps in 2014?

The 2014 ASM Teachers Camps schedule is now up and viewable online.

So, of course, I made a map...because I'm a visual learner, doncha know...

Updates: Montgomery Co added 1/23/14...Howard University, Meridian High School, Millersville University dates updates 2/16/14...Weber State and Utah University confirmed 4/8/14...Mississippi State date updated 4/26/14