Metallurgical Eye Candy

Metallurgical Eye Candy

Metallography is a method of materials analysis used to characterize the microscopic structure of a metal sample. Generally, the process involves cutting a sample from some object of interest, polishing its surface to high smoothness, and etching it with a chemical agent to highlight grain boundaries, inclusions, and other microstructural features. The sample is then imaged using one of a number of types of microscopy. The resulting pictures are often strikingly (if incidentally) beautiful. That’s OK by me, personally—incidental beauty is usually my favorite kind.

August is Metals Month

August is Metals Month

Well, what’s left of August is Metals Month, I should say. A broad subject, to be sure, and with only a couple of weeks to explore it, I want to be fairly ruthless about focusing on interesting and unusual metals themselves, and processes for working with them, rather than more general “cool stuff made from metal.”

Engineer Guy vs. the flight data recorder

Bill Hammack’s video confection is especially sweet this week. Bill scored a vintage Delta “black box” on eBay and, in this week’s installment, tears it apart on camera to show you how they built ’em in the old days to stand up to “three-thousand gees and one-thousand degrees.” I just watched it, and I’m having a hard time resisting my ebullient urge to spoil the ending for you, so I’ll just shut up and let Engineer Guy take it away. [Thanks, Bill!]

How-To:  Anodize aluminum

How-To: Anodize aluminum

Ron Newman’s fantastic page on DIY room-temperature anodizing of aluminum parts was last revised in 2007, and looks like it may be significantly older than that. Ron’s selling a how-to book, now, and a bunch of anodizing supplies, from the same page, but to me it looks like there’s more than enough free info there already for a savvy person to figure it out for him- or herself. And while Ron’s set-up, pictured above, may look intimidating, it’s actually possible to do this without a lot of expensive equipment.

Time lapse video of ‘tin pest’ metallic phase change

Really amazing. What’s going on in this cool time-lapse video from Italian YouTuber wwwperiodictableru isn’t a chemical reaction per se–it’s not oxidation or some other type of traditional corrosion. Turns out metallic or “white” tin spontaneously changes its so-called alpha crystal structure at temperatures below XX to the crumbly beta structure of “gray” tin. It’s the same stuff before and after–just different allotropes of the same element. The transformation, known as “tin pest” (Wikipedia), catalyzes itself–once it starts it just gets faster and faster.