Metallurgy (and heat treatment) is a very unique science. 

 

A lot of people shy away from it simply because they don’t understand it, or choose not to. But they’re missing out, and here’s why: Heat treatment makes parts stronger, tougher and helps them last longer, which can reduce weight and save money in the long run.

To help you understand how heat treatment actually works, our Vice President of Sales, Steve Metz, shared an old story he told his wife back when they were dating. As a materials engineer courting an interior designer, he wanted to talk about his job in a language she could understand: diamonds. Here’s Steve’s story.

My wife and I are very complementary to each other, and we use completely opposite halves of our brains. I’m the left: the science, the logic, the how-things-work half; and she’s the right: the color, the space, the creative side. Back when we first got married and I worked in a foundry, it was much easier to explain what I did. Let’s say you want to make a cast iron fire hydrant. You can go to a foundry, look at a pattern for the hydrant, watch it being pressed into sand, see the sand mold take the negative shape of the hydrant, and understand that in that negative space, molten metal will be poured to shape the parts. Done. 

Eventually, I got into the world of heat treatment. In this world, as I told my wife, we rearrange atoms for a living. Because this rearrangement of atoms is difficult to see without high magnification, it was difficult to envision what this meant.

To help her understand, I started going through the periodic table of elements and arrived at element number four, Carbon. With carbon, there are two predominant crystalline formats. One is “hexagonal, close packed,” which forms graphite — think pencils, charcoal, and so forth. It’s soft, dark in color, and burns easily.

Now, let’s rearrange the atoms. When we apply enough pressure, 150,000x atmospheric, we transform the structure to “diamond cubic.” Unlike graphite, a diamond is clear, and it’s the hardest substance known to man. It’s got a completely different set of mechanical and physical properties — and yet all we’ve done is rearrange the atoms. That’s the difference between graphite and diamonds. 

So, my wife gets it now. She can’t see the rearrangement of atoms, but she understands that the result is a change in format in something you can see or experience.

In the world of metallurgy, how do we make parts stronger? We heat treat them and rearrange things at the atomic level. You can’t see it unless viewed at high magnifications, but this new arrangement offered by austempering makes steel and iron parts stronger, and tougher and more wear-resistant.