Traditional machining operations such as turning, milling, boring, tapping, and sawing are easily performed on aluminum and its alloys. However, optimum machining parameters such as rotational speeds and feed rates are different on setups for aluminum.
Higher speeds: The inertia of aluminum alloy swarf is less than that of steel.
One-third Modulus of elasticity: Requires appropriate chucking and clamping arrangements that avoid deformation and distortion.
Faster Heat dissipation: The heat generated by the machining process is taken away with the swarf without having the time to diffuse into the metal; Thermal conductivity is higher.
2X Coefficient of linear expansion: Heating must be carefully controlled if dimensional stability are critical.
No "stress-free annealing" is required.
Non heat-treatable. Tensile strength 10 to 27 ksi: Often referred to as the pure aluminum series because it is required to have 99.0% minimum aluminum. They are weldable. When considered for fabrication, these alloys are selected primarily for their superior corrosion resistance such as in specialized chemical tanks and piping, or for their excellent electrical conductivity as in bus bar applications.
Heat-treatable. Tensile strength 27 to 62 ksi: Aluminum / Copper alloys (Copper ranging from 0.7% to 6.8%). High strength, high performance alloys that are often used for aerospace and aircraft applications. Excellent strength over a wide range of temperatures.
Non heat-treatable. Tensile strength 16 to 41 ksi: Aluminum / Manganese alloys (Manganese ranging from 0.05% to 1.8%). Moderate strength, good corrosion resistance, good formability and suited for use at elevated temperatures.
Non heat-treatable. Tensile strength 18 to 51 ksi: Aluminum / Magnesium alloys (Magnesium ranging from 0.2% to 6.2%). Highest strength of the non-heat treatable alloys. Readily weldable. Used for a wide variety of applications such as shipbuilding, transportation, pressure vessels, bridges and buildings. If more than 3.0% magnesium is not recommended for service above 150 deg F because of a potential for sensitization and susceptibility to stress corrosion cracking.
Heat-treatable. Tensile strength 18 to 58 ksi: Aluminum / Magnesium- Silicon alloys (Magnesium and Silicon approx 1.0%). Widely used in the welding fabrication industry, in the form of extrusions, and incorporated in many structural components. Magnesium-Silicide catalyzes solution heat treating for improved strength.
Heat-treatable. Tensile strength 32 to 88 ksi: Aluminum / Zinc alloys (Zinc from 0.8% to 12.0%). Some of the highest strength aluminum alloys, often used in aircraft, aerospace and competitive sporting equipment.