Watch aluminium and steel workpieces as they travel from one equipment station to the next in a machine shop. The two metals offer contrasting material properties. As a consequence of these physical differences, the steel fabrication process is necessarily different from the approach used to machine aluminium parts. To name one obvious difference, steel pieces are denser. They’re harder to cut. What other machining provisos separate the two industry-prevalent metals?
Winning the Malleability Contest
Lightweight aluminium parts deform easily. Now, while that feature may be a drawback in some impact-heavy industries, it’s seen as a benefit in the fabrication sector. Aluminium panels and tubes bend easily and can be elastically formed into any imaginable shape. Steel, a hardened alloy, requires significant quantities of energy to achieve similar results.
Untangling the Welding Question
Aluminium has a talent for conducting heat. Furthermore, it easily gains an oxide coating. Thanks to the former property, excessive surface burn through episodes are commonplace. The latter material trait is solved by comprehensively pre-treating the burn zone. As for the equipment solutions, Gas Metal Arc Welding equipment is preferred when an aluminium weld is required. On a similar steel join, several welding methods quickly get the job done. Basically, aluminium welding is a different beast, one that requires great training and skill.
Dealing with Granular Memory
This next fabrication difference is a curious one. Imagine the two alloys as they’re moving through the machine shop. They’re bent and deformed, cut and pressed. As mentioned already, the steel production line requires harder cutting blades and more bending energy because steel is a dense metal. Beyond that common sense observation, steel has form memory. Exposed to a cold worked processing phase, its microcrystalline grain absorbs stress and shape memory. This machine-imparted shape memory is typically corrected by passing the steel part through a heat treatment furnace.
Qualifying the Aluminium Difference
The lighter-than-steel option doesn’t lock in a shape when it’s manipulated by shop machines, but it does collect work fatigue. Aluminium also comes in two forms, a heat-treatable and non-heat treatable variety, so cold-worked metal fatigue is easily corrected in the heat treated type when numerous material deformations are carried out during a production run.
Just what is it we’re hinting at in this post? Well, both aluminium and steel are handled expertly in fabrication shops every day. But they’re very different, mechanically and physically. While it would be tempting to use the same tooling setup to work with both alloy families, the results would be an unmitigated washout. Aluminium and steel metal fabrication lines must be equipped with two discrete sets of tools.