Some Aluminum alloys are a lot easier to precision machine, and have quite different fatigue resistance levels.
For example:
6061 and most of the 6000 series alloys
While quite widely used, I consider them to be a pain to machine precisely. They tend to make long stringy ribbons instead of nice small chips, and the strength is sort of mediocre. An experienced machinist can make anything work, but for lesser skilled users, it is really handy if a metal breaks off in smaller chips rather than long ribbons.
IMHO, the mechanical properties are not all that much different than a piece of hard maple. I am not knocking hard maple at all, but it is a long ways from steel like properties.
The primary benefits of these alloys are flexible use range (welding, anodizing, can be machined, and most important - cheap)
2011-T3
The big benefit of this alloy is that it machines really well. The mechanical properties are acceptable and especially for people who do not do a lot of machining, it is easy to get good results. The free machining comes largely from including a small amount of lead.
7051 / 7075 - T6
These are the "real" aerospace alloys, in spite of the marketing hype of the 6000 series. The mechanical properties start to approach that of mild steel, and the machined chips are small, so it makes for easier machining.
These alloys are really designed to take shock loads and vibration (think fighter jets - pre carbon fiber ) so the main limitations are cost (roughly double) and you cannot really anodize them.
I guess all of them are better than just wood.
For example:
6061 and most of the 6000 series alloys
While quite widely used, I consider them to be a pain to machine precisely. They tend to make long stringy ribbons instead of nice small chips, and the strength is sort of mediocre. An experienced machinist can make anything work, but for lesser skilled users, it is really handy if a metal breaks off in smaller chips rather than long ribbons.
IMHO, the mechanical properties are not all that much different than a piece of hard maple. I am not knocking hard maple at all, but it is a long ways from steel like properties.
The primary benefits of these alloys are flexible use range (welding, anodizing, can be machined, and most important - cheap)
2011-T3
The big benefit of this alloy is that it machines really well. The mechanical properties are acceptable and especially for people who do not do a lot of machining, it is easy to get good results. The free machining comes largely from including a small amount of lead.
7051 / 7075 - T6
These are the "real" aerospace alloys, in spite of the marketing hype of the 6000 series. The mechanical properties start to approach that of mild steel, and the machined chips are small, so it makes for easier machining.
These alloys are really designed to take shock loads and vibration (think fighter jets - pre carbon fiber ) so the main limitations are cost (roughly double) and you cannot really anodize them.
I guess all of them are better than just wood.
