Saturday, May 12, 2007

And then an Aluminium plant!

Here in the middle of Lafayette is an Alcoa aluminium mill.

Shawn was very nice and arranged a tour for himself and myself. We were not allowed to take photos, but here are some off the internet that was pretty much what we saw. They guy who gave us the tour works in R&D and had heard of CSIRO and their work in aluminium near Melbourne.

They cast ingot and make billets, but they mostly turn them into extruded parts, or extruded then drawn tubing. The parts they can make are over 100 feet.

Here are the cast ingots.

They trim them down and cut them into billets.

Then they heat the billets typically to around 800 degrees for the extrusion process.

The process is basically pushing the metal through a hole of the right shape. The billets can start out at about 3 feet by 18 inches and end up at 100 feet with a small shaped cross section about 4-6 inches across.

The thinner the walls, the longer the sections, but they cut them to fit in the heat treatment furnace.

They can make quite complicated cross sections, but Alcoa tend to do support beams for the aerospace industry so are more basic than these.

More like these.

For tubing they can do a cold drawing process to get thin walls. This is a diagram of what happens.

This is the final tube.

It was fabulous seeing the extrusion process. They have the largest press outside Russia and it is so cool to see it loaded with billet, the die put in place and then the product squeezed out with such apparent ease. Of course the press is about the size of a diesel train engine plus pumps and things. It is awesome. The drawing process was cool because it was so fast. A 10 foot pipe became a 20 foot pipe in about 10 seconds!

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