When you think of material characteristics for parts, lightweight and strength come to mind. Naturally, so do aluminum and titanium. Both materials tick off other important boxes, such as excellent resistance to corrosion and tolerance for heat. Using 3D printing or CNC machining, these two metals have proven to be incredibly versatile for parts across a range of industries.
Aluminum and titanium are both light but for different reasons. Aluminum’s low specific gravity (2.7 g/cm3) means that it’s considerably lighter than counterparts such as steel, which is about three times as heavy. Although titanium is about two-thirds heavier than aluminum, its inherent strength means that you need less of it. In fact, you need a fraction of the amount of titanium to get the same physical strength you would get with aluminum. Titanium is used in aircraft jet engines, for example, and in spacecraft, too. Its strength and light weight reduce fuel costs.
The big difference between your two choices for machining aluminum has to do with the amount of copper in the alloy. In a head-to-head comparison, if you need something with impressive strength that can tolerate a high-friction environment, 7075 makes the most sense. 6061 does better in welding applications, it’s easier to machine and costs less. The bottom line when machining aluminum: If low weight, high tolerance to heat, and high strength are key, 7075 is the way to go.
